Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.
The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Organelles in which the splicing and excision reactions that remove introns from precursor messenger RNA molecules occur. One component of a spliceosome is five small nuclear RNA molecules (U1, U2, U4, U5, U6) that, working in conjunction with proteins, help to fold pieces of RNA into the right shapes and later splice them into the message.
Nucleotide sequences located at the ends of EXONS and recognized in pre-messenger RNA by SPLICEOSOMES. They are joined during the RNA SPLICING reaction, forming the junctions between exons.
RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The relationships of groups of organisms as reflected by their genetic makeup.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
A process whereby multiple RNA transcripts are generated from a single gene. Alternative splicing involves the splicing together of other possible sets of EXONS during the processing of some, but not all, transcripts of the gene. Thus a particular exon may be connected to any one of several alternative exons to form a mature RNA. The alternative forms of mature MESSENGER RNA produce PROTEIN ISOFORMS in which one part of the isoforms is common while the other parts are different.
A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.
The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Short chains of RNA (100-300 nucleotides long) that are abundant in the nucleus and usually complexed with proteins in snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR). Many function in the processing of messenger RNA precursors. Others, the snoRNAs (RNA, SMALL NUCLEOLAR), are involved with the processing of ribosomal RNA precursors.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.
RNA that has catalytic activity. The catalytic RNA sequence folds to form a complex surface that can function as an enzyme in reactions with itself and other molecules. It may function even in the absence of protein. There are numerous examples of RNA species that are acted upon by catalytic RNA, however the scope of this enzyme class is not limited to a particular type of substrate.
A species of fresh-water, flagellated EUKARYOTES in the phylum EUGLENIDA.
Ribonucleic acid in fungi having regulatory and catalytic roles as well as involvement in protein synthesis.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
The joining of RNA from two different genes. One type of trans-splicing is the "spliced leader" type (primarily found in protozoans such as trypanosomes and in lower invertebrates such as nematodes) which results in the addition of a capped, noncoding, spliced leader sequence to the 5' end of mRNAs. Another type of trans-splicing is the "discontinuous group II introns" type (found in plant/algal chloroplasts and plant mitochondria) which results in the joining of two independently transcribed coding sequences. Both are mechanistically similar to conventional nuclear pre-mRNA cis-splicing. Mammalian cells are also capable of trans-splicing.
The functional hereditary units of FUNGI.
Any method used for determining the location of and relative distances between genes on a chromosome.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
The functional hereditary units of PLANTS.
A form of GENE LIBRARY containing the complete DNA sequences present in the genome of a given organism. It contrasts with a cDNA library which contains only sequences utilized in protein coding (lacking introns).
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
A phylum of photosynthetic EUKARYOTA bearing double membrane-bound plastids containing chlorophyll a and b. They comprise the classical green algae, and represent over 7000 species that live in a variety of primarily aquatic habitats. Only about ten percent are marine species, most live in freshwater.
A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
A class of EUKARYOTA (traditionally algae), characterized by biflagellated cells and found in both freshwater and marine environments. Pigmentation varies but only one CHLOROPLAST is present. Unique structures include a nucleomorph and ejectosomes.
The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm, and pre-rRNA processing in the nucleolus (see RIBONUCLEOPROTEINS, SMALL NUCLEOLAR).
A phylum of fungi which have cross-walls or septa in the mycelium. The perfect state is characterized by the formation of a saclike cell (ascus) containing ascospores. Most pathogenic fungi with a known perfect state belong to this phylum.
Components of ribosomal RNA that undergo auto-catalyzed molecular rearrangements of their RNA sequence.
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U2 snRNP along with other small nuclear ribonucleoproteins (U1, U4-U6, and U5) assemble into SPLICEOSOMES that remove introns from pre-mRNA by splicing. The U2 snRNA forms base pairs with conserved sequence motifs at the branch point, which associates with a heat- and RNAase-sensitive factor in an early step of splicing.
Elements that are transcribed into RNA, reverse-transcribed into DNA and then inserted into a new site in the genome. Long terminal repeats (LTRs) similar to those from retroviruses are contained in retrotransposons and retrovirus-like elements. Retroposons, such as LONG INTERSPERSED NUCLEOTIDE ELEMENTS and SHORT INTERSPERSED NUCLEOTIDE ELEMENTS do not contain LTRs.
Deoxyribonucleic acid that makes up the genetic material of fungi.
The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)
A genus of ciliate protozoa commonly used in genetic, cytological, and other research.
Genes bearing close resemblance to known genes at different loci, but rendered non-functional by additions or deletions in structure that prevent normal transcription or translation. When lacking introns and containing a poly-A segment near the downstream end (as a result of reverse copying from processed nuclear RNA into double-stranded DNA), they are called processed genes.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
The parts of the messenger RNA sequence that do not code for product, i.e. the 5' UNTRANSLATED REGIONS and 3' UNTRANSLATED REGIONS.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
'Poisonous fishes' are aquatic organisms belonging to the Phylum Chordata and Class Pisces, that contain toxic substances either in their tissues or secretions, which can cause harmful or lethal effects when ingested, touched, or coming into contact with their released toxins.
Use for nucleic acid precursors in general or for which there is no specific heading.
A free-living soil amoeba pathogenic to humans and animals. It occurs also in water and sewage. The most commonly found species in man is NAEGLERIA FOWLERI which is the pathogen for primary amebic meningoencephalitis in primates.
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.
Any of the DNA in between gene-coding DNA, including untranslated regions, 5' and 3' flanking regions, INTRONS, non-functional pseudogenes, and non-functional repetitive sequences. This DNA may or may not encode regulatory functions.
Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.
Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.
Databases containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS; NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.
A phylum of unicellular flagellates of ancient eukaryotic lineage with unclear taxonomy. They lack a CELL WALL but are covered by a proteinaceous flexible coat, the pellicle, that allows the cell to change shape. Historically some authorities considered them to be an order of protozoa and others classed them as ALGAE (some members have CHLOROPLASTS and some don't).
Cells of the higher organisms, containing a true nucleus bounded by a nuclear membrane.
Small nuclear RNAs that are involved in the processing of pre-ribosomal RNA in the nucleolus. Box C/D containing snoRNAs (U14, U15, U16, U20, U21 and U24-U63) direct site-specific methylation of various ribose moieties. Box H/ACA containing snoRNAs (E2, E3, U19, U23, and U64-U72) direct the conversion of specific uridines to pseudouridine. Site-specific cleavages resulting in the mature ribosomal RNAs are directed by snoRNAs U3, U8, U14, U22 and the snoRNA components of RNase MRP and RNase P.
Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.
Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.
A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).
Deoxyribonucleic acid that makes up the genetic material of CHLOROPLASTS.
A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
The sequence at the 5' end of the messenger RNA that does not code for product. This sequence contains the ribosome binding site and other transcription and translation regulating sequences.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.
Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.
Enzymes that catalyze the hydrolysis of the internal bonds and thereby the formation of polynucleotides or oligonucleotides from ribo- or deoxyribonucleotide chains. EC 3.1.-.
A plant division. They are simple plants that lack vascular tissue and possess rudimentary rootlike organs (rhizoids). Like MOSSES, liverworts have alternation of generations between haploid gamete-bearing forms (gametophytes) and diploid spore-bearing forms (sporophytes).
The functional hereditary units of protozoa.
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
A species of fruit fly much used in genetics because of the large size of its chromosomes.
Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.
Ribonucleic acid in archaea having regulatory and catalytic roles as well as involvement in protein synthesis.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
The internal fragments of precursor proteins (INternal proTEINS) that are autocatalytically removed by PROTEIN SPLICING. The flanking fragments (EXTEINS) are ligated forming mature proteins. The nucleic acid sequences coding for inteins are considered to be MOBILE GENETIC ELEMENTS. Inteins are composed of self-splicing domains and an endonuclease domain which plays a role in the spread of the intein's genomic sequence. Mini-inteins are composed of the self-splicing domains only.
A phylum of fungi that produce their sexual spores (basidiospores) on the outside of the basidium. It includes forms commonly known as mushrooms, boletes, puffballs, earthstars, stinkhorns, bird's-nest fungi, jelly fungi, bracket or shelf fungi, and rust and smut fungi.
Proteins found in ribosomes. They are believed to have a catalytic function in reconstituting biologically active ribosomal subunits.
A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.
An order of CRENARCHAEOTA comprised of rod, disc, or spherical shaped, nonseptate, anaerobic, extreme thermophiles and found in solfataric hot waters, mud holes, and superheated submarine environments.
Cytochromes of the b group that have alpha-band absorption of 563-564 nm. They occur as subunits in MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III.
The genetic complement of MITOCHONDRIA as represented in their DNA.
A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.
Genotypic differences observed among individuals in a population.
Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
The genetic complement of a plant (PLANTS) as represented in its DNA.
Deoxyribonucleic acid that makes up the genetic material of plants.
A theoretical representative nucleotide or amino acid sequence in which each nucleotide or amino acid is the one which occurs most frequently at that site in the different sequences which occur in nature. The phrase also refers to an actual sequence which approximates the theoretical consensus. A known CONSERVED SEQUENCE set is represented by a consensus sequence. Commonly observed supersecondary protein structures (AMINO ACID MOTIFS) are often formed by conserved sequences.
A genus of EUKARYOTES, in the phylum EUGLENIDA, found mostly in stagnant water. Characteristics include a pellicle usually marked by spiral or longitudinal striations.

In vivo expression of the nucleolar group I intron-encoded I-dirI homing endonuclease involves the removal of a spliceosomal intron. (1/9869)

The Didymium iridis DiSSU1 intron is located in the nuclear SSU rDNA and has an unusual twin-ribozyme organization. One of the ribozymes (DiGIR2) catalyses intron excision and exon ligation. The other ribozyme (DiGIR1), which along with the endonuclease-encoding I-DirI open reading frame (ORF) is inserted in DiGIR2, carries out hydrolysis at internal processing sites (IPS1 and IPS2) located at its 3' end. Examination of the in vivo expression of DiSSU1 shows that after excision, DiSSU1 is matured further into the I-DirI mRNA by internal DiGIR1-catalysed cleavage upstream of the ORF 5' end, as well as truncation and polyadenylation downstream of the ORF 3' end. A spliceosomal intron, the first to be reported within a group I intron and the rDNA, is removed before the I-DirI mRNA associates with the polysomes. Taken together, our results imply that DiSSU1 uses a unique combination of intron-supplied ribozyme activity and adaptation to the general RNA polymerase II pathway of mRNA expression to allow a protein to be produced from the RNA polymerase I-transcribed rDNA.  (+info)

Tight binding of the 5' exon to domain I of a group II self-splicing intron requires completion of the intron active site. (2/9869)

Group II self-splicing requires the 5' exon to form base pairs with two stretches of intronic sequence (EBS1 and EBS2) which also bind the DNA target during retrotransposition of the intron. We have used dimethyl sulfate modification of bases to obtain footprints of the 5' exon on intron Pl.LSU/2 from the mitochondrion of the alga Pylaiella littoralis, as well as on truncated intron derivatives. Aside from the EBS sites, which are part of the same subdomain (ID) of ribozyme secondary structure, three distant adenines become either less or more sensitive to modification in the presence of the exon. Unexpectedly, one of these adenines in subdomain IC1 is footprinted only in the presence of the distal helix of domain V, which is involved in catalysis. While the loss of that footprint is accompanied by a 100-fold decrease in the affinity for the exon, both protection from modification and efficient binding can be restored by a separate domain V transcript, whose binding results in its own, concise footprint on domains I and III. Possible biological implications of the need for the group II active site to be complete in order to observe high-affinity binding of the 5' exon to domain I are discussed.  (+info)

A premature termination codon interferes with the nuclear function of an exon splicing enhancer in an open reading frame-dependent manner. (3/9869)

Premature translation termination codon (PTC)-mediated effects on nuclear RNA processing have been shown to be associated with a number of human genetic diseases; however, how these PTCs mediate such effects in the nucleus is unclear. A PTC at nucleotide (nt) 2018 that lies adjacent to the 5' element of a bipartite exon splicing enhancer within the NS2-specific exon of minute virus of mice P4 promoter-generated pre-mRNA caused a decrease in the accumulated levels of P4-generated R2 mRNA relative to P4-generated R1 mRNA, although the total accumulated levels of P4 product remained the same. This effect was seen in nuclear RNA and was independent of RNA stability. The 5' and 3' elements of the bipartite NS2-specific exon enhancer are redundant in function, and when the 2018 PTC was combined with a deletion of the 3' enhancer element, the exon was skipped in the majority of the viral P4-generated product. Such exon skipping in response to a PTC, but not a missense mutation at nt 2018, could be suppressed by frame shift mutations in either exon of NS2 which reopened the NS2 open reading frame, as well as by improvement of the upstream intron 3' splice site. These results suggest that a PTC can interfere with the function of an exon splicing enhancer in an open reading frame-dependent manner and that the PTC is recognized in the nucleus.  (+info)

Alterations in the conserved SL1 trans-spliced leader of Caenorhabditis elegans demonstrate flexibility in length and sequence requirements in vivo. (4/9869)

Approximately 70% of mRNAs in Caenorhabditis elegans are trans spliced to conserved 21- to 23-nucleotide leader RNAs. While the function of SL1, the major C. elegans trans-spliced leader, is unknown, SL1 RNA, which contains this leader, is essential for embryogenesis. Efforts to characterize in vivo requirements of the SL1 leader sequence have been severely constrained by the essential role of the corresponding DNA sequences in SL1 RNA transcription. We devised a heterologous expression system that circumvents this problem, making it possible to probe the length and sequence requirements of the SL1 leader without interfering with its transcription. We report that expression of SL1 from a U2 snRNA promoter rescues mutants lacking the SL1-encoding genes and that the essential embryonic function of SL1 is retained when approximately one-third of the leader sequence and/or the length of the leader is significantly altered. In contrast, although all mutant SL1 RNAs were well expressed, more severe alterations eliminate this essential embryonic function. The one non-rescuing mutant leader tested was never detected on messages, demonstrating that part of the leader sequence is essential for trans splicing in vivo. Thus, in spite of the high degree of SL1 sequence conservation, its length, primary sequence, and composition are not critical parameters of its essential embryonic function. However, particular nucleotides in the leader are essential for the in vivo function of the SL1 RNA, perhaps for its assembly into a functional snRNP or for the trans-splicing reaction.  (+info)

Promoter and exon-intron structure of the protein kinase C gene from the marine sponge Geodia cydonium: evolutionary considerations and promoter activity. (5/9869)

We report the gene structure of a key signaling molecule from a marine sponge, Geodia cydonium. The selected gene, which codes for a classical protein kinase C (cPKC), comprises 13 exons and 12 introns; the introns are, in contrast to those found in cPKC from higher Metazoa, small in size ranging from 93 nt to 359 nt. The complete gene has a length of 4229 nt and contains exons which encode the characteristic putative regulatory and catalytic domains of metazoan cPKCs. While in the regulatory domain only one intron is in phase 0, in the catalytic domain most introns are phase 0 introns, suggesting that the latter only rarely undergo module duplication. The 5'-flanking sequence of the sponge cPKC gene contains a TATA-box like motif which is located 35-26 nt upstream from the start of the longest sequenced cDNA. This 5'-flanking sequence was analyzed for promoter activity. The longest fragment (538 nt) was able to drive the expression of luciferase in transient transfections of NIH 3T3 fibroblasts; the strong activity of the sponge promoter was found to be half the one displayed by the SV40 reference promoter. Deletion analysis demonstrates that the AP4 site and the GC box which is most adjacent to the TATA box are the crucial elements for maximal promoter activity. The activity of the promoter is not changed in 3T3 cells which are kept serum starved or in the presence of a phorbol ester. In conclusion, these data present the phylogenetically oldest cPKC gene which contains in the 5'-flanking region a promoter functional in the heterologous mammalian cell system.  (+info)

Interleukin-18 binding protein: a novel modulator of the Th1 cytokine response. (6/9869)

An interleukin-18 binding protein (IL-18BP) was purified from urine by chromatography on IL-18 beads, sequenced, cloned, and expressed in COS7 cells. IL-18BP abolished IL-18 induction of interferon-gamma (IFNgamma), IL-8, and activation of NF-kappaB in vitro. Administration of IL-18BP to mice abrogated circulating IFNgamma following LPS. Thus, IL-18BP functions as an inhibitor of the early Th1 cytokine response. IL-18BP is constitutively expressed in the spleen, belongs to the immunoglobulin superfamily, and has limited homology to the IL-1 type II receptor. Its gene was localized on human chromosome 11q13, and no exon coding for a transmembrane domain was found in an 8.3 kb genomic sequence. Several Poxviruses encode putative proteins highly homologous to IL-18BP, suggesting that viral products may attenuate IL-18 and interfere with the cytotoxic T cell response.  (+info)

The stability and fate of a spliced intron from vertebrate cells. (7/9869)

Introns constitute most of the length of typical pre-mRNAs in vertebrate cells. Thus, the turnover rate of introns may significantly influence the availability of ribonucleotides and splicing factors for further rounds of transcription and RNA splicing, respectively. Given the importance of intron turnover, it is surprising that there have been no reports on the half-life of introns from higher eukaryotic cells. Here, we determined the stability of IVS1Cbeta1, the first intron from the constant region of the mouse T-cell receptor-beta, (TCR-beta) gene. Using a tetracycline (tet)-regulated promoter, we demonstrate that spliced IVS1Cbeta1 and its pre-mRNA had half-lives of 6.0+/-1.4 min and 3.7+/-1.0 min, respectively. We also examined the half-lives of these transcripts by using actinomycin D (Act.D). Act.D significantly stabilized IVS1Cbeta1 and its pre-mRNA, suggesting that Act.D not only blocks transcription but exerts rapid and direct posttranscriptional effects in the nucleus. We observed that in vivo spliced IVS1Cbeta1 accumulated predominantly as lariat molecules that use a consensus branchpoint nucleotide. The accumulation of IVS1Cbeta1 as a lariat did not result from an intrinsic inability to be debranched, as it could be debranched in vitro, albeit somewhat less efficiently than an adenovirus intron. Subcellular-fractionation and sucrose-gradient analyses showed that most spliced IVS1Cbeta1 lariats cofractionated with pre-mRNA, but not always with mRNA in the nucleus. Some IVS1Cbeta1 also appeared to be selectively exported to the cytoplasm, whereas TCR-beta pre-mRNA remained in the nucleus. This study constitutes the first detailed analysis of the stability and fate of a spliced nuclear intron in vivo.  (+info)

Genome-wide bioinformatic and molecular analysis of introns in Saccharomyces cerevisiae. (8/9869)

Introns have typically been discovered in an ad hoc fashion: introns are found as a gene is characterized for other reasons. As complete eukaryotic genome sequences become available, better methods for predicting RNA processing signals in raw sequence will be necessary in order to discover genes and predict their expression. Here we present a catalog of 228 yeast introns, arrived at through a combination of bioinformatic and molecular analysis. Introns annotated in the Saccharomyces Genome Database (SGD) were evaluated, questionable introns were removed after failing a test for splicing in vivo, and known introns absent from the SGD annotation were added. A novel branchpoint sequence, AAUUAAC, was identified within an annotated intron that lacks a six-of-seven match to the highly conserved branchpoint consensus UACUAAC. Analysis of the database corroborates many conclusions about pre-mRNA substrate requirements for splicing derived from experimental studies, but indicates that splicing in yeast may not be as rigidly determined by splice-site conservation as had previously been thought. Using this database and a molecular technique that directly displays the lariat intron products of spliced transcripts (intron display), we suggest that the current set of 228 introns is still not complete, and that additional intron-containing genes remain to be discovered in yeast. The database can be accessed at http://www.cse.ucsc.edu/research/compbi o/yeast_introns.html.  (+info)

Introns are non-coding sequences of DNA that are present within the genes of eukaryotic organisms, including plants, animals, and humans. Introns are removed during the process of RNA splicing, in which the initial RNA transcript is cut and reconnected to form a mature, functional RNA molecule.

After the intron sequences are removed, the remaining coding sequences, known as exons, are joined together to create a continuous stretch of genetic information that can be translated into a protein or used to produce non-coding RNAs with specific functions. The removal of introns allows for greater flexibility in gene expression and regulation, enabling the generation of multiple proteins from a single gene through alternative splicing.

In summary, introns are non-coding DNA sequences within genes that are removed during RNA processing to create functional RNA molecules or proteins.

RNA splicing is a post-transcriptional modification process in which the non-coding sequences (introns) are removed and the coding sequences (exons) are joined together in a messenger RNA (mRNA) molecule. This results in a continuous mRNA sequence that can be translated into a single protein. Alternative splicing, where different combinations of exons are included or excluded, allows for the creation of multiple proteins from a single gene.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Exons are the coding regions of DNA that remain in the mature, processed mRNA after the removal of non-coding intronic sequences during RNA splicing. These exons contain the information necessary to encode proteins, as they specify the sequence of amino acids within a polypeptide chain. The arrangement and order of exons can vary between different genes and even between different versions of the same gene (alternative splicing), allowing for the generation of multiple protein isoforms from a single gene. This complexity in exon structure and usage significantly contributes to the diversity and functionality of the proteome.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

A spliceosome is a complex of ribonucleoprotein (RNP) particles found in the nucleus of eukaryotic cells that removes introns (non-coding sequences) from precursor messenger RNA (pre-mRNA) and joins exons (coding sequences) together to form mature mRNA. This process is called splicing, which is an essential step in gene expression and protein synthesis. Spliceosomes are composed of five small nuclear ribonucleoprotein particles (snRNPs), known as U1, U2, U4/U6, and U5 snRNPs, and numerous proteins. The assembly of spliceosomes and the splicing reaction are highly regulated and can be influenced by various factors, including cis-acting elements in pre-mRNA and trans-acting factors such as serine/arginine-rich (SR) proteins.

RNA splice sites are specific sequences on the pre-messenger RNA (pre-mRNA) molecule where the splicing process occurs during gene expression in eukaryotic cells. The pre-mRNA contains introns and exons, which are non-coding and coding regions of the RNA, respectively.

The splicing process removes the introns and joins together the exons to form a mature mRNA molecule that can be translated into a protein. The splice sites are recognized by the spliceosome, a complex of proteins and small nuclear RNAs (snRNAs) that catalyze the splicing reaction.

There are two main types of splice sites: the 5' splice site and the 3' splice site. The 5' splice site is located at the junction between the 5' end of the intron and the 3' end of the exon, while the 3' splice site is located at the junction between the 3' end of the intron and the 5' end of the exon.

The 5' splice site contains a conserved GU sequence, while the 3' splice site contains a conserved AG sequence. These sequences are recognized by the snRNAs in the spliceosome, which bind to them and facilitate the splicing reaction.

Mutations or variations in RNA splice sites can lead to abnormal splicing and result in diseases such as cancer, neurodegenerative disorders, and genetic disorders.

RNA precursors, also known as primary transcripts or pre-messenger RNAs (pre-mRNAs), refer to the initial RNA molecules that are synthesized during the transcription process in which DNA is copied into RNA. These precursor molecules still contain non-coding sequences and introns, which need to be removed through a process called splicing, before they can become mature and functional RNAs such as messenger RNAs (mRNAs), ribosomal RNAs (rRNAs), or transfer RNAs (tRNAs).

Pre-mRNAs undergo several processing steps, including 5' capping, 3' polyadenylation, and splicing, to generate mature mRNA molecules that can be translated into proteins. The accurate and efficient production of RNA precursors and their subsequent processing are crucial for gene expression and regulation in cells.

Molecular evolution is the process of change in the DNA sequence or protein structure over time, driven by mechanisms such as mutation, genetic drift, gene flow, and natural selection. It refers to the evolutionary study of changes in DNA, RNA, and proteins, and how these changes accumulate and lead to new species and diversity of life. Molecular evolution can be used to understand the history and relationships among different organisms, as well as the functional consequences of genetic changes.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Phylogeny is the evolutionary history and relationship among biological entities, such as species or genes, based on their shared characteristics. In other words, it refers to the branching pattern of evolution that shows how various organisms have descended from a common ancestor over time. Phylogenetic analysis involves constructing a tree-like diagram called a phylogenetic tree, which depicts the inferred evolutionary relationships among organisms or genes based on molecular sequence data or other types of characters. This information is crucial for understanding the diversity and distribution of life on Earth, as well as for studying the emergence and spread of diseases.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

Nucleic acid conformation refers to the three-dimensional structure that nucleic acids (DNA and RNA) adopt as a result of the bonding patterns between the atoms within the molecule. The primary structure of nucleic acids is determined by the sequence of nucleotides, while the conformation is influenced by factors such as the sugar-phosphate backbone, base stacking, and hydrogen bonding.

Two common conformations of DNA are the B-form and the A-form. The B-form is a right-handed helix with a diameter of about 20 Å and a pitch of 34 Å, while the A-form has a smaller diameter (about 18 Å) and a shorter pitch (about 25 Å). RNA typically adopts an A-form conformation.

The conformation of nucleic acids can have significant implications for their function, as it can affect their ability to interact with other molecules such as proteins or drugs. Understanding the conformational properties of nucleic acids is therefore an important area of research in molecular biology and medicine.

Alternative splicing is a process in molecular biology that occurs during the post-transcriptional modification of pre-messenger RNA (pre-mRNA) molecules. It involves the removal of non-coding sequences, known as introns, and the joining together of coding sequences, or exons, to form a mature messenger RNA (mRNA) molecule that can be translated into a protein.

In alternative splicing, different combinations of exons are selected and joined together to create multiple distinct mRNA transcripts from a single pre-mRNA template. This process increases the diversity of proteins that can be produced from a limited number of genes, allowing for greater functional complexity in organisms.

Alternative splicing is regulated by various cis-acting elements and trans-acting factors that bind to specific sequences in the pre-mRNA molecule and influence which exons are included or excluded during splicing. Abnormal alternative splicing has been implicated in several human diseases, including cancer, neurological disorders, and cardiovascular disease.

A gene is a specific sequence of nucleotides in DNA that carries genetic information. Genes are the fundamental units of heredity and are responsible for the development and function of all living organisms. They code for proteins or RNA molecules, which carry out various functions within cells and are essential for the structure, function, and regulation of the body's tissues and organs.

Each gene has a specific location on a chromosome, and each person inherits two copies of every gene, one from each parent. Variations in the sequence of nucleotides in a gene can lead to differences in traits between individuals, including physical characteristics, susceptibility to disease, and responses to environmental factors.

Medical genetics is the study of genes and their role in health and disease. It involves understanding how genes contribute to the development and progression of various medical conditions, as well as identifying genetic risk factors and developing strategies for prevention, diagnosis, and treatment.

Sequence homology in nucleic acids refers to the similarity or identity between the nucleotide sequences of two or more DNA or RNA molecules. It is often used as a measure of biological relationship between genes, organisms, or populations. High sequence homology suggests a recent common ancestry or functional constraint, while low sequence homology may indicate a more distant relationship or different functions.

Nucleic acid sequence homology can be determined by various methods such as pairwise alignment, multiple sequence alignment, and statistical analysis. The degree of homology is typically expressed as a percentage of identical or similar nucleotides in a given window of comparison.

It's important to note that the interpretation of sequence homology depends on the biological context and the evolutionary distance between the sequences compared. Therefore, functional and experimental validation is often necessary to confirm the significance of sequence homology.

In genetics, sequence alignment is the process of arranging two or more DNA, RNA, or protein sequences to identify regions of similarity or homology between them. This is often done using computational methods to compare the nucleotide or amino acid sequences and identify matching patterns, which can provide insight into evolutionary relationships, functional domains, or potential genetic disorders. The alignment process typically involves adjusting gaps and mismatches in the sequences to maximize the similarity between them, resulting in an aligned sequence that can be visually represented and analyzed.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Small nuclear RNA (snRNA) are a type of RNA molecules that are typically around 100-300 nucleotides in length. They are found within the nucleus of eukaryotic cells and are components of small nuclear ribonucleoproteins (snRNPs), which play important roles in various aspects of RNA processing, including splicing of pre-messenger RNA (pre-mRNA) and regulation of transcription.

There are several classes of snRNAs, each with a distinct function. The most well-studied class is the spliceosomal snRNAs, which include U1, U2, U4, U5, and U6 snRNAs. These snRNAs form complexes with proteins to form small nuclear ribonucleoprotein particles (snRNPs) that recognize specific sequences in pre-mRNA and catalyze the removal of introns during splicing.

Other classes of snRNAs include signal recognition particle (SRP) RNA, which is involved in targeting proteins to the endoplasmic reticulum, and Ro60 RNA, which is associated with autoimmune diseases such as systemic lupus erythematosus.

Overall, small nuclear RNAs are essential components of the cellular machinery that regulates gene expression and protein synthesis in eukaryotic cells.

DNA Sequence Analysis is the systematic determination of the order of nucleotides in a DNA molecule. It is a critical component of modern molecular biology, genetics, and genetic engineering. The process involves determining the exact order of the four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - in a DNA molecule or fragment. This information is used in various applications such as identifying gene mutations, studying evolutionary relationships, developing molecular markers for breeding, and diagnosing genetic diseases.

The process of DNA Sequence Analysis typically involves several steps, including DNA extraction, PCR amplification (if necessary), purification, sequencing reaction, and electrophoresis. The resulting data is then analyzed using specialized software to determine the exact sequence of nucleotides.

In recent years, high-throughput DNA sequencing technologies have revolutionized the field of genomics, enabling the rapid and cost-effective sequencing of entire genomes. This has led to an explosion of genomic data and new insights into the genetic basis of many diseases and traits.

A conserved sequence in the context of molecular biology refers to a pattern of nucleotides (in DNA or RNA) or amino acids (in proteins) that has remained relatively unchanged over evolutionary time. These sequences are often functionally important and are highly conserved across different species, indicating strong selection pressure against changes in these regions.

In the case of protein-coding genes, the corresponding amino acid sequence is deduced from the DNA sequence through the genetic code. Conserved sequences in proteins may indicate structurally or functionally important regions, such as active sites or binding sites, that are critical for the protein's activity. Similarly, conserved non-coding sequences in DNA may represent regulatory elements that control gene expression.

Identifying conserved sequences can be useful for inferring evolutionary relationships between species and for predicting the function of unknown genes or proteins.

A catalytic RNA, often referred to as a ribozyme, is a type of RNA molecule that has the ability to act as an enzyme and catalyze chemical reactions. These RNA molecules contain specific sequences and structures that allow them to bind to other molecules and accelerate chemical reactions without being consumed in the process.

Ribozymes play important roles in various biological processes, such as RNA splicing, translation regulation, and gene expression. One of the most well-known ribozymes is the self-splicing intron found in certain RNA molecules, which can excise itself from the host RNA and then ligase the flanking exons together.

The discovery of catalytic RNAs challenged the central dogma of molecular biology, which held that proteins were solely responsible for carrying out biological catalysis. The finding that RNA could also function as an enzyme opened up new avenues of research and expanded our understanding of the complexity and versatility of biological systems.

'Euglena gracilis' is a species of unicellular flagellate belonging to the genus Euglena. It is a common freshwater organism, characterized by its elongated, flexible shape and distinct eyespot that allows it to move towards light sources. 'Euglena gracilis' contains chloroplasts for photosynthesis but can also consume other organic matter through phagocytosis, making it a facultative autotroph. It is often used as a model organism in scientific research due to its unique combination of features from both plant and animal kingdoms.

Ribonucleic acid (RNA) is a type of nucleic acid that plays a crucial role in the process of gene expression. There are several types of RNA molecules, including messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). These RNA molecules help to transcribe DNA into mRNA, which is then translated into proteins by the ribosomes.

Fungi are a group of eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. Like other eukaryotes, fungi contain DNA and RNA as part of their genetic material. The RNA in fungi is similar to the RNA found in other organisms, including humans, and plays a role in gene expression and protein synthesis.

A specific medical definition of "RNA, fungal" does not exist, as RNA is a fundamental component of all living organisms, including fungi. However, RNA can be used as a target for antifungal drugs, as certain enzymes involved in RNA synthesis and processing are unique to fungi and can be inhibited by these drugs. For example, the antifungal drug flucytosine is converted into a toxic metabolite that inhibits fungal RNA and DNA synthesis.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

Restriction mapping is a technique used in molecular biology to identify the location and arrangement of specific restriction endonuclease recognition sites within a DNA molecule. Restriction endonucleases are enzymes that cut double-stranded DNA at specific sequences, producing fragments of various lengths. By digesting the DNA with different combinations of these enzymes and analyzing the resulting fragment sizes through techniques such as agarose gel electrophoresis, researchers can generate a restriction map - a visual representation of the locations and distances between recognition sites on the DNA molecule. This information is crucial for various applications, including cloning, genome analysis, and genetic engineering.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

An open reading frame (ORF) is a continuous stretch of DNA or RNA sequence that has the potential to be translated into a protein. It begins with a start codon (usually "ATG" in DNA, which corresponds to "AUG" in RNA) and ends with a stop codon ("TAA", "TAG", or "TGA" in DNA; "UAA", "UAG", or "UGA" in RNA). The sequence between these two points is called a coding sequence (CDS), which, when transcribed into mRNA and translated into amino acids, forms a polypeptide chain.

In eukaryotic cells, ORFs can be located in either protein-coding genes or non-coding regions of the genome. In prokaryotic cells, multiple ORFs may be present on a single strand of DNA, often organized into operons that are transcribed together as a single mRNA molecule.

It's important to note that not all ORFs necessarily represent functional proteins; some may be pseudogenes or result from errors in genome annotation. Therefore, additional experimental evidence is typically required to confirm the expression and functionality of a given ORF.

Biological evolution is the change in the genetic composition of populations of organisms over time, from one generation to the next. It is a process that results in descendants differing genetically from their ancestors. Biological evolution can be driven by several mechanisms, including natural selection, genetic drift, gene flow, and mutation. These processes can lead to changes in the frequency of alleles (variants of a gene) within populations, resulting in the development of new species and the extinction of others over long periods of time. Biological evolution provides a unifying explanation for the diversity of life on Earth and is supported by extensive evidence from many different fields of science, including genetics, paleontology, comparative anatomy, and biogeography.

Genetic models are theoretical frameworks used in genetics to describe and explain the inheritance patterns and genetic architecture of traits, diseases, or phenomena. These models are based on mathematical equations and statistical methods that incorporate information about gene frequencies, modes of inheritance, and the effects of environmental factors. They can be used to predict the probability of certain genetic outcomes, to understand the genetic basis of complex traits, and to inform medical management and treatment decisions.

There are several types of genetic models, including:

1. Mendelian models: These models describe the inheritance patterns of simple genetic traits that follow Mendel's laws of segregation and independent assortment. Examples include autosomal dominant, autosomal recessive, and X-linked inheritance.
2. Complex trait models: These models describe the inheritance patterns of complex traits that are influenced by multiple genes and environmental factors. Examples include heart disease, diabetes, and cancer.
3. Population genetics models: These models describe the distribution and frequency of genetic variants within populations over time. They can be used to study evolutionary processes, such as natural selection and genetic drift.
4. Quantitative genetics models: These models describe the relationship between genetic variation and phenotypic variation in continuous traits, such as height or IQ. They can be used to estimate heritability and to identify quantitative trait loci (QTLs) that contribute to trait variation.
5. Statistical genetics models: These models use statistical methods to analyze genetic data and infer the presence of genetic associations or linkage. They can be used to identify genetic risk factors for diseases or traits.

Overall, genetic models are essential tools in genetics research and medical genetics, as they allow researchers to make predictions about genetic outcomes, test hypotheses about the genetic basis of traits and diseases, and develop strategies for prevention, diagnosis, and treatment.

Complementary DNA (cDNA) is a type of DNA that is synthesized from a single-stranded RNA molecule through the process of reverse transcription. In this process, the enzyme reverse transcriptase uses an RNA molecule as a template to synthesize a complementary DNA strand. The resulting cDNA is therefore complementary to the original RNA molecule and is a copy of its coding sequence, but it does not contain non-coding regions such as introns that are present in genomic DNA.

Complementary DNA is often used in molecular biology research to study gene expression, protein function, and other genetic phenomena. For example, cDNA can be used to create cDNA libraries, which are collections of cloned cDNA fragments that represent the expressed genes in a particular cell type or tissue. These libraries can then be screened for specific genes or gene products of interest. Additionally, cDNA can be used to produce recombinant proteins in heterologous expression systems, allowing researchers to study the structure and function of proteins that may be difficult to express or purify from their native sources.

Trans-splicing is a process in which two different RNA molecules are spliced together to form a single, chimeric RNA molecule. This process involves the removal of introns (non-coding sequences) from both RNA molecules and the ligation of the remaining exons (coding sequences) to create a new RNA molecule that contains genetic information from both original RNAs.

In cis-splicing, which is the more common form of splicing, introns are removed and exons are ligated within the same RNA molecule. However, in trans-splicing, the exons to be ligated come from two separate RNA molecules that have been transcribed from different genes or different regions of the same gene.

Trans-splicing is found in a variety of organisms, including some higher eukaryotes such as humans, where it plays a role in generating genetic diversity and regulating gene expression. It can also occur in certain viruses, where it is used to generate new mRNA molecules that encode for essential viral proteins.

Fungal genes refer to the genetic material present in fungi, which are eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. The genetic material of fungi is composed of DNA, just like in other eukaryotes, and is organized into chromosomes located in the nucleus of the cell.

Fungal genes are segments of DNA that contain the information necessary to produce proteins and RNA molecules required for various cellular functions. These genes are transcribed into messenger RNA (mRNA) molecules, which are then translated into proteins by ribosomes in the cytoplasm.

Fungal genomes have been sequenced for many species, revealing a diverse range of genes that encode proteins involved in various cellular processes such as metabolism, signaling, and regulation. Comparative genomic analyses have also provided insights into the evolutionary relationships among different fungal lineages and have helped to identify unique genetic features that distinguish fungi from other eukaryotes.

Understanding fungal genes and their functions is essential for advancing our knowledge of fungal biology, as well as for developing new strategies to control fungal pathogens that can cause diseases in humans, animals, and plants.

Chromosome mapping, also known as physical mapping, is the process of determining the location and order of specific genes or genetic markers on a chromosome. This is typically done by using various laboratory techniques to identify landmarks along the chromosome, such as restriction enzyme cutting sites or patterns of DNA sequence repeats. The resulting map provides important information about the organization and structure of the genome, and can be used for a variety of purposes, including identifying the location of genes associated with genetic diseases, studying evolutionary relationships between organisms, and developing genetic markers for use in breeding or forensic applications.

A genome is the complete set of genetic material (DNA, or in some viruses, RNA) present in a single cell of an organism. It includes all of the genes, both coding and noncoding, as well as other regulatory elements that together determine the unique characteristics of that organism. The human genome, for example, contains approximately 3 billion base pairs and about 20,000-25,000 protein-coding genes.

The term "genome" was first coined by Hans Winkler in 1920, derived from the word "gene" and the suffix "-ome," which refers to a complete set of something. The study of genomes is known as genomics.

Understanding the genome can provide valuable insights into the genetic basis of diseases, evolution, and other biological processes. With advancements in sequencing technologies, it has become possible to determine the entire genomic sequence of many organisms, including humans, and use this information for various applications such as personalized medicine, gene therapy, and biotechnology.

A gene in plants, like in other organisms, is a hereditary unit that carries genetic information from one generation to the next. It is a segment of DNA (deoxyribonucleic acid) that contains the instructions for the development and function of an organism. Genes in plants determine various traits such as flower color, plant height, resistance to diseases, and many others. They are responsible for encoding proteins and RNA molecules that play crucial roles in the growth, development, and reproduction of plants. Plant genes can be manipulated through traditional breeding methods or genetic engineering techniques to improve crop yield, enhance disease resistance, and increase nutritional value.

A genomic library is a collection of cloned DNA fragments that represent the entire genetic material of an organism. It serves as a valuable resource for studying the function, organization, and regulation of genes within a given genome. Genomic libraries can be created using different types of vectors, such as bacterial artificial chromosomes (BACs), yeast artificial chromosomes (YACs), or plasmids, to accommodate various sizes of DNA inserts. These libraries facilitate the isolation and manipulation of specific genes or genomic regions for further analysis, including sequencing, gene expression studies, and functional genomics research.

Species specificity is a term used in the field of biology, including medicine, to refer to the characteristic of a biological entity (such as a virus, bacterium, or other microorganism) that allows it to interact exclusively or preferentially with a particular species. This means that the biological entity has a strong affinity for, or is only able to infect, a specific host species.

For example, HIV is specifically adapted to infect human cells and does not typically infect other animal species. Similarly, some bacterial toxins are species-specific and can only affect certain types of animals or humans. This concept is important in understanding the transmission dynamics and host range of various pathogens, as well as in developing targeted therapies and vaccines.

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

Chlorophyta is a division of green algae, also known as green plants. This group includes a wide variety of simple, aquatic organisms that contain chlorophylls a and b, which gives them their characteristic green color. They are a diverse group, ranging from unicellular forms to complex multicellular seaweeds. Chlorophyta is a large and varied division with approximately 7,00

Southern blotting is a type of membrane-based blotting technique that is used in molecular biology to detect and locate specific DNA sequences within a DNA sample. This technique is named after its inventor, Edward M. Southern.

In Southern blotting, the DNA sample is first digested with one or more restriction enzymes, which cut the DNA at specific recognition sites. The resulting DNA fragments are then separated based on their size by gel electrophoresis. After separation, the DNA fragments are denatured to convert them into single-stranded DNA and transferred onto a nitrocellulose or nylon membrane.

Once the DNA has been transferred to the membrane, it is hybridized with a labeled probe that is complementary to the sequence of interest. The probe can be labeled with radioactive isotopes, fluorescent dyes, or chemiluminescent compounds. After hybridization, the membrane is washed to remove any unbound probe and then exposed to X-ray film (in the case of radioactive probes) or scanned (in the case of non-radioactive probes) to detect the location of the labeled probe on the membrane.

The position of the labeled probe on the membrane corresponds to the location of the specific DNA sequence within the original DNA sample. Southern blotting is a powerful tool for identifying and characterizing specific DNA sequences, such as those associated with genetic diseases or gene regulation.

Cryptophyta is a taxonomic division that refers to a group of unicellular algae called cryptomonads. These organisms are characterized by the presence of unique organelles called ejectisomes, which they use for defense and prey capture. They are also known for having two flagella and distinctive eyespot structures. Cryptophytes are widely distributed in aquatic environments and can be found in both freshwater and marine habitats. Some species are capable of carrying out photosynthesis, while others are heterotrophic, obtaining nutrients by consuming other organisms. The study of cryptomonads is important for understanding the evolution of eukaryotic cells and their complex organelles.

Base composition in genetics refers to the relative proportion of the four nucleotide bases (adenine, thymine, guanine, and cytosine) in a DNA or RNA molecule. In DNA, adenine pairs with thymine, and guanine pairs with cytosine, so the base composition is often expressed in terms of the ratio of adenine + thymine (A-T) to guanine + cytosine (G-C). This ratio can vary between species and even between different regions of the same genome. The base composition can provide important clues about the function, evolution, and structure of genetic material.

RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.

Small nuclear ribonucleoproteins (snRNPs) are a type of ribonucleoprotein (RNP) found within the nucleus of eukaryotic cells. They are composed of small nuclear RNA (snRNA) molecules and associated proteins, which are involved in various aspects of RNA processing, particularly in the modification and splicing of messenger RNA (mRNA).

The snRNPs play a crucial role in the formation of spliceosomes, large ribonucleoprotein complexes that remove introns (non-coding sequences) from pre-mRNA and join exons (coding sequences) together to form mature mRNA. Each snRNP contains a specific snRNA molecule, such as U1, U2, U4, U5, or U6, which recognizes and binds to specific sequences within the pre-mRNA during splicing. The associated proteins help stabilize the snRNP structure and facilitate its interactions with other components of the spliceosome.

In addition to their role in splicing, some snRNPs are also involved in other cellular processes, such as transcription regulation, RNA export, and DNA damage response. Dysregulation or mutations in snRNP components have been implicated in various human diseases, including cancer, neurological disorders, and autoimmune diseases.

Ascomycota is a phylum in the kingdom Fungi, also known as sac fungi. This group includes both unicellular and multicellular organisms, such as yeasts, mold species, and morel mushrooms. Ascomycetes are characterized by their reproductive structures called ascus, which contain typically eight haploid spores produced sexually through a process called ascogony. Some members of this phylum have significant ecological and economic importance, as they can be decomposers, mutualistic symbionts, or plant pathogens causing various diseases. Examples include the baker's yeast Saccharomyces cerevisiae, ergot fungus Claviceps purpurea, and morel mushroom Morchella esculenta.

'RNA, Ribosomal, Self-Splicing' refers to a specific type of RNA molecule that is capable of catalyzing its own splicing reaction. In other words, it is a form of ribosomal RNA (rRNA) that can excise introns and ligate exons without the need for any external proteins or enzymes. This self-splicing ability was first discovered in certain rRNAs found in lower organisms such as Tetrahymena and occurs through a process known as group I intron self-splicing.

Ribosomal RNA is a type of non-coding RNA that plays a crucial role in the process of protein synthesis or translation. It is a major component of ribosomes, which are complex structures composed of both rRNA and proteins. The rRNA within the ribosome helps to facilitate the binding of messenger RNA (mRNA) and transfer RNA (tRNA) during translation, allowing for the accurate decoding and synthesis of proteins.

Self-splicing rRNAs are unique in that they contain introns, which are non-coding sequences that must be removed from the primary transcript before the mature rRNA can function properly. In self-splicing rRNAs, this splicing process is catalyzed by the RNA itself, rather than by proteins or other enzymes. This intriguing property has led to significant research into the mechanisms of RNA folding and catalysis, as well as the potential role of self-splicing RNAs in genetic regulation and evolution.

A ribonucleoprotein, U2 small nuclear (U2 snRNP) is a type of spliceosomal small nuclear ribonucleoprotein (snRNP) complex that plays a crucial role in the pre-messenger RNA (pre-mRNA) splicing process during gene expression in eukaryotic cells.

Pre-mRNA splicing is the removal of non-coding sequences, called introns, from the pre-mRNA molecule and the joining together of the remaining coding sequences, or exons, to form a continuous mRNA sequence that can be translated into protein. U2 snRNPs are essential components of the spliceosome, the large ribonucleoprotein complex responsible for pre-mRNA splicing.

The U2 snRNP is composed of several proteins and a small nuclear RNA (snRNA) molecule called U2 small nuclear RNA (U2 snRNA). The U2 snRNA binds to specific sequences within the pre-mRNA, forming part of the intron's branch site, which helps define the boundaries of the exons and introns. This interaction facilitates the recognition and assembly of other spliceosomal components, ultimately leading to the precise excision of introns and ligation of exons in the mature mRNA molecule.

In summary, U2 snRNP is a ribonucleoprotein complex involved in pre-mRNA splicing, where it plays a critical role in recognizing and processing intron-exon boundaries during gene expression in eukaryotic cells.

Retroelements are a type of mobile genetic element that can move within a host genome by reverse transcription of an RNA intermediate. They are called "retro" because they replicate through a retrotransposition process, which involves the reverse transcription of their RNA into DNA, and then integration of the resulting cDNA into a new location in the genome.

Retroelements are typically divided into two main categories: long terminal repeat (LTR) retrotransposons and non-LTR retrotransposons. LTR retrotransposons have direct repeats of several hundred base pairs at their ends, similar to retroviruses, while non-LTR retrotransposons lack these repeats.

Retroelements are widespread in eukaryotic genomes and can make up a significant fraction of the DNA content. They are thought to play important roles in genome evolution, including the creation of new genes and the regulation of gene expression. However, they can also cause genetic instability and disease when they insert into or near functional genes.

Fungal DNA refers to the genetic material present in fungi, which are a group of eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. The DNA of fungi, like that of all living organisms, is made up of nucleotides that are arranged in a double helix structure.

Fungal DNA contains the genetic information necessary for the growth, development, and reproduction of fungi. This includes the instructions for making proteins, which are essential for the structure and function of cells, as well as other important molecules such as enzymes and nucleic acids.

Studying fungal DNA can provide valuable insights into the biology and evolution of fungi, as well as their potential uses in medicine, agriculture, and industry. For example, researchers have used genetic engineering techniques to modify the DNA of fungi to produce drugs, biofuels, and other useful products. Additionally, understanding the genetic makeup of pathogenic fungi can help scientists develop new strategies for preventing and treating fungal infections.

Ribosomal RNA (rRNA) is a type of RNA molecule that is a key component of ribosomes, which are the cellular structures where protein synthesis occurs in cells. In ribosomes, rRNA plays a crucial role in the process of translation, where genetic information from messenger RNA (mRNA) is translated into proteins.

Ribosomal RNA is synthesized in the nucleus and then transported to the cytoplasm, where it assembles with ribosomal proteins to form ribosomes. Within the ribosome, rRNA provides a structural framework for the assembly of the ribosome and also plays an active role in catalyzing the formation of peptide bonds between amino acids during protein synthesis.

There are several different types of rRNA molecules, including 5S, 5.8S, 18S, and 28S rRNA, which vary in size and function. These rRNA molecules are highly conserved across different species, indicating their essential role in protein synthesis and cellular function.

Tetrahymena is not a medical term itself, but it is a genus of unicellular organisms known as ciliates. They are commonly found in freshwater environments and can be studied in the field of biology and microbiology. Some species of Tetrahymena have been used in scientific research, including studies on genetics, cell division, and protein function. It is not a term that would typically be used in a medical context.

Pseudogenes are defined in medical and genetics terminology as non-functional segments of DNA that resemble functional genes, such as protein-coding genes or RNA genes, but have lost their ability to be expressed or produce a functional product. They are often characterized by the presence of mutations, such as frameshifts, premature stop codons, or deletions, that prevent them from being transcribed or translated into functional proteins or RNAs.

Pseudogenes can arise through various mechanisms, including gene duplication followed by degenerative mutations, retrotransposition of processed mRNA, and the insertion of transposable elements. While they were once considered "genomic fossils" with no biological relevance, recent research has shown that pseudogenes may play important roles in regulating gene expression, modulating protein function, and contributing to disease processes.

It's worth noting that there is ongoing debate in the scientific community about the precise definition and functional significance of pseudogenes, as some may still retain residual functions or regulatory potential.

Promoter regions in genetics refer to specific DNA sequences located near the transcription start site of a gene. They serve as binding sites for RNA polymerase and various transcription factors that regulate the initiation of gene transcription. These regulatory elements help control the rate of transcription and, therefore, the level of gene expression. Promoter regions can be composed of different types of sequences, such as the TATA box and CAAT box, and their organization and composition can vary between different genes and species.

Untranslated regions (UTRs) are segments of messenger RNA (mRNA) that do not contain information for the synthesis of proteins. They are located at the 5' end (5' UTR) and 3' end (3' UTR) of the mRNA, outside of the coding sequence (CDS). The 5' UTR contains regulatory elements that control translation initiation, while the 3' UTR contains sequences involved in mRNA stability, localization, and translation efficiency. These regions do not code for proteins but play a crucial role in post-transcriptional regulation of gene expression.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

'Poisonous fishes' are species of fish that contain toxic substances in their bodies, which can cause harm or injury to other organisms, including humans. These toxins can be present in various parts of the fish, such as the flesh, skin, organs, or even in the form of venomous spines.

There are several types of poisonous fishes, including:

1. Pufferfish (Fugu): These fish contain a potent neurotoxin called tetrodotoxin (TTX) in their organs, especially the liver and ovaries. TTX is highly toxic and can cause paralysis and death if ingested in even small amounts.
2. Stonefish: Stonefishes are venomous fishes that have sharp, spiny dorsal fins that can inject a painful toxin into the skin when stepped on or touched. The venom can cause severe pain, swelling, and tissue damage, and in some cases, it can lead to respiratory failure and death.
3. Blue-ringed octopuses: While not technically fish, blue-ringed octopuses are often included in discussions of poisonous marine life. They have venom glands that produce a powerful neurotoxin called tetrodotoxin (TTX), which can cause paralysis and death if it enters the bloodstream.
4. Cone snails: Cone snails are predatory mollusks that use a harpoon-like tooth to inject venom into their prey. Some species of cone snail have venom that contains powerful neurotoxins, which can cause paralysis and death in humans.
5. Lionfish: Lionfish are venomous fishes that have spines on their dorsal, pelvic, and anal fins that can inject a painful toxin into the skin when touched or stepped on. The venom can cause pain, swelling, and other symptoms, but it is rarely fatal to humans.

It's important to note that many species of fish can become toxic if they consume harmful algae blooms (HABs) or other contaminants in their environment. These "toxic fishes" are not considered poisonous by definition, as their toxicity is not inherent to their biology.

Nucleic acid precursors are the molecules that are used in the synthesis of nucleotides, which are the building blocks of nucleic acids, including DNA and RNA. The two main types of nucleic acid precursors are nucleoside triphosphates (deoxyribonucleoside triphosphates for DNA and ribonucleoside triphosphates for RNA) and their corresponding pentose sugars (deoxyribose for DNA and ribose for RNA).

Nucleoside triphosphates consist of a nitrogenous base, a pentose sugar, and three phosphate groups. The nitrogenous bases in nucleic acids are classified as purines (adenine and guanine) or pyrimidines (thymine, cytosine, and uracil). In the synthesis of nucleotides, nucleophilic attack by the nitrogenous base on a pentose sugar in the form of a phosphate ester leads to the formation of a glycosidic bond between the base and the sugar. The addition of two more phosphate groups through anhydride linkages forms the nucleoside triphosphate.

The synthesis of nucleic acids involves the sequential addition of nucleotides to a growing chain, with the removal of a pyrophosphate group from each nucleotide providing energy for the reaction. The process is catalyzed by enzymes called polymerases, which use nucleic acid templates to ensure the correct base-pairing and sequence of nucleotides in the final product.

In summary, nucleic acid precursors are the molecules that provide the building blocks for the synthesis of DNA and RNA, and include nucleoside triphosphates and their corresponding pentose sugars.

Naegleria is a genus of free-living excavate protists, commonly found in warm freshwater such as lakes, rivers, and hot springs. It's also found in soil. The most notorious species within this genus is Naegleria fowleri, which is known to cause a rare but often fatal brain infection called primary amoebic meningoencephalitis (PAM) in humans. This occurs when the amoeba enters the nose and migrates to the brain through the olfactory nerve. It's important to note that this type of infection is extremely rare, but can be deadly if not treated promptly and effectively.

A multigene family is a group of genetically related genes that share a common ancestry and have similar sequences or structures. These genes are arranged in clusters on a chromosome and often encode proteins with similar functions. They can arise through various mechanisms, including gene duplication, recombination, and transposition. Multigene families play crucial roles in many biological processes, such as development, immunity, and metabolism. Examples of multigene families include the globin genes involved in oxygen transport, the immune system's major histocompatibility complex (MHC) genes, and the cytochrome P450 genes associated with drug metabolism.

DNA restriction enzymes, also known as restriction endonucleases, are a type of enzyme that cut double-stranded DNA at specific recognition sites. These enzymes are produced by bacteria and archaea as a defense mechanism against foreign DNA, such as that found in bacteriophages (viruses that infect bacteria).

Restriction enzymes recognize specific sequences of nucleotides (the building blocks of DNA) and cleave the phosphodiester bonds between them. The recognition sites for these enzymes are usually palindromic, meaning that the sequence reads the same in both directions when facing the opposite strands of DNA.

Restriction enzymes are widely used in molecular biology research for various applications such as genetic engineering, genome mapping, and DNA fingerprinting. They allow scientists to cut DNA at specific sites, creating precise fragments that can be manipulated and analyzed. The use of restriction enzymes has been instrumental in the development of recombinant DNA technology and the Human Genome Project.

Intergenic DNA refers to the stretches of DNA that are located between genes. These regions do not contain coding sequences for proteins or RNA and thus were once thought to be "junk" DNA with no function. However, recent research has shown that intergenic DNA can play important roles in the regulation of gene expression, chromosome structure and stability, and other cellular processes. Intergenic DNA may contain various types of regulatory elements such as enhancers, silencers, insulators, and promoters that control the transcription of nearby genes. Additionally, intergenic DNA can also include repetitive sequences, transposable elements, and other non-coding RNAs that have diverse functions in the cell.

A group of chordate animals (Phylum Chordata) that have a vertebral column, or backbone, made up of individual vertebrae. This group includes mammals, birds, reptiles, amphibians, and fish. Vertebrates are characterized by the presence of a notochord, which is a flexible, rod-like structure that runs along the length of the body during development; a dorsal hollow nerve cord; and pharyngeal gill slits at some stage in their development. The vertebral column provides support and protection for the spinal cord and allows for the development of complex movements and behaviors.

Repetitive sequences in nucleic acid refer to repeated stretches of DNA or RNA nucleotide bases that are present in a genome. These sequences can vary in length and can be arranged in different patterns such as direct repeats, inverted repeats, or tandem repeats. In some cases, these repetitive sequences do not code for proteins and are often found in non-coding regions of the genome. They can play a role in genetic instability, regulation of gene expression, and evolutionary processes. However, certain types of repeat expansions have been associated with various neurodegenerative disorders and other human diseases.

Mitochondrial DNA (mtDNA) is the genetic material present in the mitochondria, which are specialized structures within cells that generate energy. Unlike nuclear DNA, which is present in the cell nucleus and inherited from both parents, mtDNA is inherited solely from the mother.

MtDNA is a circular molecule that contains 37 genes, including 13 genes that encode for proteins involved in oxidative phosphorylation, a process that generates energy in the form of ATP. The remaining genes encode for rRNAs and tRNAs, which are necessary for protein synthesis within the mitochondria.

Mutations in mtDNA can lead to a variety of genetic disorders, including mitochondrial diseases, which can affect any organ system in the body. These mutations can also be used in forensic science to identify individuals and establish biological relationships.

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

DNA transposable elements, also known as transposons or jumping genes, are mobile genetic elements that can change their position within a genome. They are composed of DNA sequences that include genes encoding the enzymes required for their own movement (transposase) and regulatory elements. When activated, the transposase recognizes specific sequences at the ends of the element and catalyzes the excision and reintegration of the transposable element into a new location in the genome. This process can lead to genetic variation, as the insertion of a transposable element can disrupt the function of nearby genes or create new combinations of gene regulatory elements. Transposable elements are widespread in both prokaryotic and eukaryotic genomes and are thought to play a significant role in genome evolution.

A nucleic acid database is a type of biological database that contains sequence, structure, and functional information about nucleic acids, such as DNA and RNA. These databases are used in various fields of biology, including genomics, molecular biology, and bioinformatics, to store, search, and analyze nucleic acid data.

Some common types of nucleic acid databases include:

1. Nucleotide sequence databases: These databases contain the primary nucleotide sequences of DNA and RNA molecules from various organisms. Examples include GenBank, EMBL-Bank, and DDBJ.
2. Structure databases: These databases contain three-dimensional structures of nucleic acids determined by experimental methods such as X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Examples include the Protein Data Bank (PDB) and the Nucleic Acid Database (NDB).
3. Functional databases: These databases contain information about the functions of nucleic acids, such as their roles in gene regulation, transcription, and translation. Examples include the Gene Ontology (GO) database and the RegulonDB.
4. Genome databases: These databases contain genomic data for various organisms, including whole-genome sequences, gene annotations, and genetic variations. Examples include the Human Genome Database (HGD) and the Ensembl Genome Browser.
5. Comparative databases: These databases allow for the comparison of nucleic acid sequences or structures across different species or conditions. Examples include the Comparative RNA Web (CRW) Site and the Sequence Alignment and Modeling (SAM) system.

Nucleic acid databases are essential resources for researchers to study the structure, function, and evolution of nucleic acids, as well as to develop new tools and methods for analyzing and interpreting nucleic acid data.

Euglenida is a group of unicellular organisms that are characterized by having a flexible, elongated shape and a pair of flagella used for movement. They belong to the kingdom Protista and can be found in various aquatic environments. Some members of this group have chloroplasts and can perform photosynthesis, while others are heterotrophic and obtain their nutrients by consuming other organisms or organic matter.

Euglenids are known for their ability to change their shape and movement patterns in response to environmental stimuli, such as light and chemicals. They have a unique eyespot that detects light and helps them to navigate towards sources of light. Some euglenids also have the ability to form temporary cysts to survive unfavorable conditions.

Euglenida is a diverse group with over 700 species, some of which are important members of the plankton community in aquatic ecosystems. While they are generally harmless to humans and other animals, some species can produce toxins that can be harmful to other organisms in their environment.

Eukaryotic cells are complex cells that characterize the cells of all living organisms except bacteria and archaea. They are typically larger than prokaryotic cells and contain a true nucleus and other membrane-bound organelles. The nucleus houses the genetic material, DNA, which is organized into chromosomes. Other organelles include mitochondria, responsible for energy production; chloroplasts, present in plant cells and responsible for photosynthesis; endoplasmic reticulum, involved in protein synthesis; Golgi apparatus, involved in the processing and transport of proteins and lipids; lysosomes, involved in digestion and waste disposal; and vacuoles, involved in storage and waste management. Eukaryotic cells also have a cytoskeleton made up of microtubules, intermediate filaments, and actin filaments that provide structure, support, and mobility to the cell.

Small nucleolar RNAs (snoRNAs) are a specific class of small RNA molecules that range in size from 60 to 300 nucleotides. They are primarily located in the dense granules of the nucleus called nucleoli, which are membrane-less organelles where ribosome biogenesis occurs.

SnoRNAs guide the chemical modification of other RNA molecules, mainly ribosomal RNAs (rRNAs) and small nuclear RNAs (snRNAs). They function as guides for site-specific post-transcriptional modifications, such as 2'-O-methylation and pseudouridination, of their target RNAs. These modifications are essential for the stability, structure, and functionality of the target RNAs.

SnoRNAs can be classified into two main groups based on their secondary structures and sequence motifs:

1. C/D box snoRNAs: These snoRNAs contain conserved sequence motifs known as the C (RUGAUGA) and D (CUGA) boxes, which are located in the 5' and 3' ends of the snoRNA, respectively. They typically guide 2'-O-methylation of their target RNAs.
2. H/ACA box snoRNAs: These snoRNAs contain conserved sequence motifs known as the H (ANANNA) and ACA boxes, which are located in the 5' and 3' ends of the snoRNA, respectively. They typically guide pseudouridination of their target RNAs.

SnoRNAs are encoded by either host genes or as independent transcription units. In some cases, they can be found within introns of protein-coding or non-protein-coding genes and are processed from the primary transcript (pre-mRNA or intron lariat) during splicing.

In summary, small nucleolar RNAs (snoRNAs) are a class of small RNA molecules that guide post-transcriptional modifications, mainly 2'-O-methylation and pseudouridination, of other RNA molecules such as ribosomal RNAs (rRNAs), small nuclear RNAs (snRNAs), and messenger RNAs (mRNAs).

Ribonucleic acid (RNA) in plants refers to the long, single-stranded molecules that are essential for the translation of genetic information from deoxyribonucleic acid (DNA) into proteins. RNA is a nucleic acid, like DNA, and it is composed of a ribose sugar backbone with attached nitrogenous bases (adenine, uracil, guanine, and cytosine).

In plants, there are several types of RNA that play specific roles in the gene expression process:

1. Messenger RNA (mRNA): This type of RNA carries genetic information copied from DNA in the form of a sequence of three-base code units called codons. These codons specify the order of amino acids in a protein.
2. Transfer RNA (tRNA): tRNAs are small RNA molecules that serve as adaptors between the mRNA and the amino acids during protein synthesis. Each tRNA has a specific anticodon sequence that base-pairs with a complementary codon on the mRNA, and it carries a specific amino acid that corresponds to that codon.
3. Ribosomal RNA (rRNA): rRNAs are structural components of ribosomes, which are large macromolecular complexes where protein synthesis occurs. In plants, there are several types of rRNAs, including the 18S, 5.8S, and 25S/28S rRNAs, that form the core of the ribosome and help catalyze peptide bond formation during protein synthesis.
4. Small nuclear RNA (snRNA): These are small RNA molecules that play a role in RNA processing, such as splicing, where introns (non-coding sequences) are removed from pre-mRNA and exons (coding sequences) are joined together to form mature mRNAs.
5. MicroRNA (miRNA): These are small non-coding RNAs that regulate gene expression by binding to complementary sequences in target mRNAs, leading to their degradation or translation inhibition.

Overall, these different types of RNAs play crucial roles in various aspects of RNA metabolism, gene regulation, and protein synthesis in plants.

Chloroplasts are specialized organelles found in the cells of green plants, algae, and some protists. They are responsible for carrying out photosynthesis, which is the process by which these organisms convert light energy from the sun into chemical energy in the form of organic compounds, such as glucose.

Chloroplasts contain the pigment chlorophyll, which absorbs light energy from the sun. They also contain a system of membranes and enzymes that convert carbon dioxide and water into glucose and oxygen through a series of chemical reactions known as the Calvin cycle. This process not only provides energy for the organism but also releases oxygen as a byproduct, which is essential for the survival of most life forms on Earth.

Chloroplasts are believed to have originated from ancient cyanobacteria that were engulfed by early eukaryotic cells and eventually became integrated into their host's cellular machinery through a process called endosymbiosis. Over time, chloroplasts evolved to become an essential component of plant and algal cells, contributing to their ability to carry out photosynthesis and thrive in a wide range of environments.

A codon is a sequence of three adjacent nucleotides in DNA or RNA that specifies the insertion of a particular amino acid during protein synthesis, or signals the beginning or end of translation. In DNA, these triplets are read during transcription to produce a complementary mRNA molecule, which is then translated into a polypeptide chain during translation. There are 64 possible codons in the standard genetic code, with 61 encoding for specific amino acids and three serving as stop codons that signal the termination of protein synthesis.

Chloroplast DNA (cpDNA) refers to the genetic material present in the chloroplasts, which are organelles found in the cells of photosynthetic organisms such as plants, algae, and some bacteria. Chloroplasts are responsible for capturing sunlight energy and converting it into chemical energy through the process of photosynthesis.

Chloroplast DNA is circular and contains a small number of genes compared to the nuclear genome. It encodes for some of the essential components required for chloroplast function, including proteins involved in photosynthesis, transcription, and translation. The majority of chloroplast proteins are encoded by the nuclear genome and are imported into the chloroplast after being synthesized in the cytoplasm.

Chloroplast DNA is inherited maternally in most plants, meaning that it is passed down from the maternal parent to their offspring through the egg cell. This mode of inheritance has been used in plant breeding and genetic engineering to introduce desirable traits into crops.

Fungi, in the context of medical definitions, are a group of eukaryotic organisms that include microorganisms such as yeasts and molds, as well as the more familiar mushrooms. The study of fungi is known as mycology.

Fungi can exist as unicellular organisms or as multicellular filamentous structures called hyphae. They are heterotrophs, which means they obtain their nutrients by decomposing organic matter or by living as parasites on other organisms. Some fungi can cause various diseases in humans, animals, and plants, known as mycoses. These infections range from superficial, localized skin infections to systemic, life-threatening invasive diseases.

Examples of fungal infections include athlete's foot (tinea pedis), ringworm (dermatophytosis), candidiasis (yeast infection), histoplasmosis, coccidioidomycosis, and aspergillosis. Fungal infections can be challenging to treat due to the limited number of antifungal drugs available and the potential for drug resistance.

I apologize for any confusion, but "plants" is not a term that has a medical definition. The term "plants" refers to a large and diverse group of organisms that obtain their energy through photosynthesis, which is the process of converting sunlight into chemical energy. Plants are typically characterized by having cells with cell walls containing cellulose, chloroplasts containing the pigment chlorophyll, and the ability to synthesize their own food through photosynthesis.

In a medical or biological context, you might be thinking of "plant-based" or "phytomedicine," which refer to the use of plants or plant extracts as a form of medicine or treatment. Phytomedicines have been used for thousands of years in many traditional systems of medicine, and some plant-derived compounds have been found to have therapeutic benefits in modern medicine as well. However, "plants" itself does not have a medical definition.

Untranslated regions (UTRs) are sections of an mRNA molecule that do not contain information for protein synthesis. There are two types of UTRs: 5' UTR, which is located at the 5' end of the mRNA molecule, and 3' UTR, which is located at the 3' end.

The 5' UTR typically contains regulatory elements that control the translation of the mRNA into protein. These elements can affect the efficiency and timing of translation, as well as the stability of the mRNA molecule. The 5' UTR may also contain upstream open reading frames (uORFs), which are short sequences that can be translated into small peptides and potentially regulate the translation of the main coding sequence.

The length and sequence composition of the 5' UTR can have significant impacts on gene expression, and variations in these regions have been associated with various diseases, including cancer and neurological disorders. Therefore, understanding the structure and function of 5' UTRs is an important area of research in molecular biology and genetics.

"Saccharomyces cerevisiae" is not typically considered a medical term, but it is a scientific name used in the field of microbiology. It refers to a species of yeast that is commonly used in various industrial processes, such as baking and brewing. It's also widely used in scientific research due to its genetic tractability and eukaryotic cellular organization.

However, it does have some relevance to medical fields like medicine and nutrition. For example, certain strains of S. cerevisiae are used as probiotics, which can provide health benefits when consumed. They may help support gut health, enhance the immune system, and even assist in the digestion of certain nutrients.

In summary, "Saccharomyces cerevisiae" is a species of yeast with various industrial and potential medical applications.

Post-transcriptional RNA processing refers to the modifications and regulations that occur on RNA molecules after the transcription of DNA into RNA. This process includes several steps:

1. 5' capping: The addition of a cap structure, usually a methylated guanosine triphosphate (GTP), to the 5' end of the RNA molecule. This helps protect the RNA from degradation and plays a role in its transport, stability, and translation.
2. 3' polyadenylation: The addition of a string of adenosine residues (poly(A) tail) to the 3' end of the RNA molecule. This process is important for mRNA stability, export from the nucleus, and translation initiation.
3. Intron removal and exon ligation: Eukaryotic pre-messenger RNAs (pre-mRNAs) contain intronic sequences that do not code for proteins. These introns are removed by a process called splicing, where the flanking exons are joined together to form a continuous mRNA sequence. Alternative splicing can lead to different mature mRNAs from a single pre-mRNA, increasing transcriptomic and proteomic diversity.
4. RNA editing: Specific nucleotide changes in RNA molecules that alter the coding potential or regulatory functions of RNA. This process is catalyzed by enzymes like ADAR (Adenosine Deaminases Acting on RNA) and APOBEC (Apolipoprotein B mRNA Editing Catalytic Polypeptide-like).
5. Chemical modifications: Various chemical modifications can occur on RNA nucleotides, such as methylation, pseudouridination, and isomerization. These modifications can influence RNA stability, localization, and interaction with proteins or other RNAs.
6. Transport and localization: Mature mRNAs are transported from the nucleus to the cytoplasm for translation. In some cases, specific mRNAs are localized to particular cellular compartments to ensure local protein synthesis.
7. Degradation: RNA molecules have finite lifetimes and undergo degradation by various ribonucleases (RNases). The rate of degradation can be influenced by factors such as RNA structure, modifications, or interactions with proteins.

RNA-binding proteins (RBPs) are a class of proteins that selectively interact with RNA molecules to form ribonucleoprotein complexes. These proteins play crucial roles in the post-transcriptional regulation of gene expression, including pre-mRNA processing, mRNA stability, transport, localization, and translation. RBPs recognize specific RNA sequences or structures through their modular RNA-binding domains, which can be highly degenerate and allow for the recognition of a wide range of RNA targets. The interaction between RBPs and RNA is often dynamic and can be regulated by various post-translational modifications of the proteins or by environmental stimuli, allowing for fine-tuning of gene expression in response to changing cellular needs. Dysregulation of RBP function has been implicated in various human diseases, including neurological disorders and cancer.

Endonucleases are enzymes that cleave, or cut, phosphodiester bonds within a polynucleotide chain, specifically within the same molecule of DNA or RNA. They can be found in all living organisms and play crucial roles in various biological processes, such as DNA replication, repair, and recombination.

Endonucleases can recognize specific nucleotide sequences (sequence-specific endonucleases) or have no sequence preference (non-specific endonucleases). Some endonucleases generate sticky ends, overhangs of single-stranded DNA after cleavage, while others produce blunt ends without any overhang.

These enzymes are widely used in molecular biology techniques, such as restriction digestion, cloning, and genome editing (e.g., CRISPR-Cas9 system). Restriction endonucleases recognize specific DNA sequences called restriction sites and cleave the phosphodiester bonds at or near these sites, generating defined fragment sizes that can be separated by agarose gel electrophoresis. This property is essential for various applications in genetic engineering and biotechnology.

I'm sorry for any confusion, but "Hepatophyta" is not a valid medical or scientific term in modern usage. It appears to be a combination of the Greek word "hepar" meaning "liver" and the suffix "-phyta" which is used to denote a plant or group of plants in taxonomy. However, it is not a term that is recognized or used in modern biology or medicine.

It's possible that you may be thinking of "Hepatica," which is a genus of flowering plants in the family Ranunculaceae. These plants are also known as liverworts, although they should not be confused with actual liverworts, which are non-vascular plants in the division Marchantiophyta.

If you have any further questions or if there is another term you would like me to define, please let me know!

Genes in protozoa refer to the hereditary units of these single-celled organisms that carry genetic information necessary for their growth, development, and reproduction. These genes are made up of DNA (deoxyribonucleic acid) molecules, which contain sequences of nucleotide bases that code for specific proteins or RNA molecules. Protozoan genes are responsible for various functions, such as metabolism, response to environmental stimuli, and reproduction.

It is important to note that the study of protozoan genes has contributed significantly to our understanding of genetics and evolution, particularly in areas such as molecular biology, cell biology, and genomics. However, there is still much to be learned about the genetic diversity and complexity of these organisms, which continue to be an active area of research.

Nucleic acid hybridization is a process in molecular biology where two single-stranded nucleic acids (DNA, RNA) with complementary sequences pair together to form a double-stranded molecule through hydrogen bonding. The strands can be from the same type of nucleic acid or different types (i.e., DNA-RNA or DNA-cDNA). This process is commonly used in various laboratory techniques, such as Southern blotting, Northern blotting, polymerase chain reaction (PCR), and microarray analysis, to detect, isolate, and analyze specific nucleic acid sequences. The hybridization temperature and conditions are critical to ensure the specificity of the interaction between the two strands.

'Drosophila melanogaster' is the scientific name for a species of fruit fly that is commonly used as a model organism in various fields of biological research, including genetics, developmental biology, and evolutionary biology. Its small size, short generation time, large number of offspring, and ease of cultivation make it an ideal subject for laboratory studies. The fruit fly's genome has been fully sequenced, and many of its genes have counterparts in the human genome, which facilitates the understanding of genetic mechanisms and their role in human health and disease.

Here is a brief medical definition:

Drosophila melanogaster (droh-suh-fih-luh meh-lon-guh-ster): A species of fruit fly used extensively as a model organism in genetic, developmental, and evolutionary research. Its genome has been sequenced, revealing many genes with human counterparts, making it valuable for understanding genetic mechanisms and their role in human health and disease.

Expressed Sequence Tags (ESTs) are short, single-pass DNA sequences that are derived from cDNA libraries. They represent a quick and cost-effective method for large-scale sequencing of gene transcripts and provide an unbiased view of the genes being actively expressed in a particular tissue or developmental stage. ESTs can be used to identify and study new genes, to analyze patterns of gene expression, and to develop molecular markers for genetic mapping and genome analysis.

Archaeal RNA refers to the Ribonucleic acid (RNA) molecules that are present in archaea, which are a domain of single-celled microorganisms. RNA is a nucleic acid that plays a crucial role in various biological processes, such as protein synthesis, gene expression, and regulation of cellular activities.

Archaeal RNAs can be categorized into different types based on their functions, including:

1. Messenger RNA (mRNA): It carries genetic information from DNA to the ribosome, where it is translated into proteins.
2. Transfer RNA (tRNA): It helps in translating the genetic code present in mRNA into specific amino acids during protein synthesis.
3. Ribosomal RNA (rRNA): It is a structural and functional component of ribosomes, where protein synthesis occurs.
4. Non-coding RNA: These are RNAs that do not code for proteins but have regulatory functions in gene expression and other cellular processes.

Archaeal RNAs share similarities with both bacterial and eukaryotic RNAs, but they also possess unique features that distinguish them from the other two domains of life. For example, archaeal rRNAs contain unique sequence motifs and secondary structures that are not found in bacteria or eukaryotes. These differences suggest that archaeal RNAs have evolved to adapt to the extreme environments where many archaea live.

Overall, understanding the structure, function, and evolution of archaeal RNA is essential for gaining insights into the biology of these unique microorganisms and their roles in various cellular processes.

'Arabidopsis' is a genus of small flowering plants that are part of the mustard family (Brassicaceae). The most commonly studied species within this genus is 'Arabidopsis thaliana', which is often used as a model organism in plant biology and genetics research. This plant is native to Eurasia and Africa, and it has a small genome that has been fully sequenced. It is known for its short life cycle, self-fertilization, and ease of growth, making it an ideal subject for studying various aspects of plant biology, including development, metabolism, and response to environmental stresses.

An intein is a type of mobile genetic element that can be found within the proteins of various organisms, including bacteria, archaea, and eukaryotes. Inteins are intervening sequences of amino acids that are capable of self-excising from their host protein through a process called protein splicing.

Protein splicing involves the cleavage of the intein from the flanking sequences (known as exteins) and the formation of a peptide bond between the two exteins, resulting in a mature, functional protein. Inteins can also ligate themselves to form circular proteins or can be transferred horizontally between different organisms through various mechanisms.

Inteins have been identified as potential targets for drug development due to their essential role in the survival and virulence of certain pathogenic bacteria. Additionally, the protein splicing mechanism of inteins has been harnessed for various biotechnological applications, such as the production of recombinant proteins and the development of biosensors.

Basidiomycota is a phylum in the kingdom Fungi that consists of organisms commonly known as club fungi or club mushrooms. The name Basidiomycota is derived from the presence of a characteristic reproductive structure called a basidium, which is where spores are produced.

The basidiomycetes include many familiar forms such as mushrooms, toadstools, bracket fungi, and other types of polypores. They have a complex life cycle that involves both sexual and asexual reproduction. The sexual reproductive stage produces a characteristic fruiting body, which may be microscopic or highly visible, depending on the species.

Basidiomycota fungi play important ecological roles in decomposing organic matter, forming mutualistic relationships with plants, and acting as parasites on other organisms. Some species are economically important, such as edible mushrooms, while others can be harmful or even deadly to humans and animals.

Ribosomal proteins are a type of protein that play a crucial role in the structure and function of ribosomes, which are complex molecular machines found within all living cells. Ribosomes are responsible for translating messenger RNA (mRNA) into proteins during the process of protein synthesis.

Ribosomal proteins can be divided into two categories based on their location within the ribosome:

1. Large ribosomal subunit proteins: These proteins are associated with the larger of the two subunits of the ribosome, which is responsible for catalyzing peptide bond formation during protein synthesis.
2. Small ribosomal subunit proteins: These proteins are associated with the smaller of the two subunits of the ribosome, which is responsible for binding to the mRNA and decoding the genetic information it contains.

Ribosomal proteins have a variety of functions, including helping to stabilize the structure of the ribosome, assisting in the binding of substrates and cofactors necessary for protein synthesis, and regulating the activity of the ribosome. Mutations in ribosomal proteins can lead to a variety of human diseases, including developmental disorders, neurological conditions, and cancer.

Computational biology is a branch of biology that uses mathematical and computational methods to study biological data, models, and processes. It involves the development and application of algorithms, statistical models, and computational approaches to analyze and interpret large-scale molecular and phenotypic data from genomics, transcriptomics, proteomics, metabolomics, and other high-throughput technologies. The goal is to gain insights into biological systems and processes, develop predictive models, and inform experimental design and hypothesis testing in the life sciences. Computational biology encompasses a wide range of disciplines, including bioinformatics, systems biology, computational genomics, network biology, and mathematical modeling of biological systems.

Thermoproteales is an order of archaea belonging to the class Thermoprotei, within the phylum Crenarchaeota. These are extremophilic organisms, meaning they thrive in extreme environments that are hostile to most life forms. Specifically, Thermoproteales are thermophiles, capable of growing at relatively high temperatures, typically between 75-105 degrees Celsius (167-221 degrees Fahrenheit). They are primarily found in volcanic habitats such as hot springs and deep-sea hydrothermal vents.

Members of Thermoproteales have a unique method of energy production, using sulfur compounds and hydrogen gas as their primary energy sources through a process called sulfur respiration or chemolithotrophy. This sets them apart from other archaea and most bacteria, which typically use organic compounds for energy.

The cells of Thermoproteales are usually rod-shaped and may be either motile with flagella or non-motile. They have a unique cell wall structure that does not contain peptidoglycan, a common component in bacterial cell walls. Instead, their cell walls consist mainly of proteins and polysaccharides.

It is important to note that while I strive to provide accurate information, medical definitions can be complex and ever-evolving. Therefore, for the most up-to-date and comprehensive understanding, it's always best to consult authoritative resources or speak with a healthcare professional.

Cytochromes b are a group of electron transport proteins that contain a heme c group, which is the prosthetic group responsible for their redox activity. They play a crucial role in the electron transport chain (ETC) located in the inner mitochondrial membrane of eukaryotic cells and in the plasma membrane of prokaryotic cells.

The cytochromes b are part of Complex III, also known as the cytochrome bc1 complex or ubiquinol-cytochrome c reductase, in the ETC. In this complex, they function as electron carriers between ubiquinone (Q) and cytochrome c, participating in the process of oxidative phosphorylation to generate ATP.

There are multiple isoforms of cytochromes b found in various organisms, with different numbers of subunits and structures. However, they all share a common function as essential components of the electron transport chain, facilitating the transfer of electrons during cellular respiration and energy production.

A mitochondrial genome refers to the genetic material present in the mitochondria, which are small organelles found in the cytoplasm of eukaryotic cells (cells with a true nucleus). The mitochondrial genome is typically circular and contains a relatively small number of genes compared to the nuclear genome.

Mitochondrial DNA (mtDNA) encodes essential components of the electron transport chain, which is vital for cellular respiration and energy production. MtDNA also contains genes that code for some mitochondrial tRNAs and rRNAs needed for protein synthesis within the mitochondria.

In humans, the mitochondrial genome is about 16.6 kilobases in length and consists of 37 genes: 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and 13 protein-coding genes. The mitochondrial genome is inherited maternally, as sperm contribute very few or no mitochondria during fertilization. Mutations in the mitochondrial genome can lead to various genetic disorders, often affecting tissues with high energy demands, such as muscle and nerve cells.

A "gene library" is not a recognized term in medical genetics or molecular biology. However, the closest concept that might be referred to by this term is a "genomic library," which is a collection of DNA clones that represent the entire genetic material of an organism. These libraries are used for various research purposes, such as identifying and studying specific genes or gene functions.

Genetic variation refers to the differences in DNA sequences among individuals and populations. These variations can result from mutations, genetic recombination, or gene flow between populations. Genetic variation is essential for evolution by providing the raw material upon which natural selection acts. It can occur within a single gene, between different genes, or at larger scales, such as differences in the number of chromosomes or entire sets of chromosomes. The study of genetic variation is crucial in understanding the genetic basis of diseases and traits, as well as the evolutionary history and relationships among species.

Northern blotting is a laboratory technique used in molecular biology to detect and analyze specific RNA molecules (such as mRNA) in a mixture of total RNA extracted from cells or tissues. This technique is called "Northern" blotting because it is analogous to the Southern blotting method, which is used for DNA detection.

The Northern blotting procedure involves several steps:

1. Electrophoresis: The total RNA mixture is first separated based on size by running it through an agarose gel using electrical current. This separates the RNA molecules according to their length, with smaller RNA fragments migrating faster than larger ones.

2. Transfer: After electrophoresis, the RNA bands are denatured (made single-stranded) and transferred from the gel onto a nitrocellulose or nylon membrane using a technique called capillary transfer or vacuum blotting. This step ensures that the order and relative positions of the RNA fragments are preserved on the membrane, similar to how they appear in the gel.

3. Cross-linking: The RNA is then chemically cross-linked to the membrane using UV light or heat treatment, which helps to immobilize the RNA onto the membrane and prevent it from washing off during subsequent steps.

4. Prehybridization: Before adding the labeled probe, the membrane is prehybridized in a solution containing blocking agents (such as salmon sperm DNA or yeast tRNA) to minimize non-specific binding of the probe to the membrane.

5. Hybridization: A labeled nucleic acid probe, specific to the RNA of interest, is added to the prehybridization solution and allowed to hybridize (form base pairs) with its complementary RNA sequence on the membrane. The probe can be either a DNA or an RNA molecule, and it is typically labeled with a radioactive isotope (such as ³²P) or a non-radioactive label (such as digoxigenin).

6. Washing: After hybridization, the membrane is washed to remove unbound probe and reduce background noise. The washing conditions (temperature, salt concentration, and detergent concentration) are optimized based on the stringency required for specific hybridization.

7. Detection: The presence of the labeled probe is then detected using an appropriate method, depending on the type of label used. For radioactive probes, this typically involves exposing the membrane to X-ray film or a phosphorimager screen and analyzing the resulting image. For non-radioactive probes, detection can be performed using colorimetric, chemiluminescent, or fluorescent methods.

8. Data analysis: The intensity of the signal is quantified and compared to controls (such as housekeeping genes) to determine the relative expression level of the RNA of interest. This information can be used for various purposes, such as identifying differentially expressed genes in response to a specific treatment or comparing gene expression levels across different samples or conditions.

A plant genome refers to the complete set of genetic material or DNA present in the cells of a plant. It contains all the hereditary information necessary for the development and functioning of the plant, including its structural and functional characteristics. The plant genome includes both coding regions that contain instructions for producing proteins and non-coding regions that have various regulatory functions.

The plant genome is composed of several types of DNA molecules, including chromosomes, which are located in the nucleus of the cell. Each chromosome contains one or more genes, which are segments of DNA that code for specific proteins or RNA molecules. Plants typically have multiple sets of chromosomes, with each set containing a complete copy of the genome.

The study of plant genomes is an active area of research in modern biology, with important applications in areas such as crop improvement, evolutionary biology, and medical research. Advances in DNA sequencing technologies have made it possible to determine the complete sequences of many plant genomes, providing valuable insights into their structure, function, and evolution.

DNA, or deoxyribonucleic acid, is the genetic material present in the cells of all living organisms, including plants. In plants, DNA is located in the nucleus of a cell, as well as in chloroplasts and mitochondria. Plant DNA contains the instructions for the development, growth, and function of the plant, and is passed down from one generation to the next through the process of reproduction.

The structure of DNA is a double helix, formed by two strands of nucleotides that are linked together by hydrogen bonds. Each nucleotide contains a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base. There are four types of nitrogenous bases in DNA: adenine (A), guanine (G), cytosine (C), and thymine (T). Adenine pairs with thymine, and guanine pairs with cytosine, forming the rungs of the ladder that make up the double helix.

The genetic information in DNA is encoded in the sequence of these nitrogenous bases. Large sequences of bases form genes, which provide the instructions for the production of proteins. The process of gene expression involves transcribing the DNA sequence into a complementary RNA molecule, which is then translated into a protein.

Plant DNA is similar to animal DNA in many ways, but there are also some differences. For example, plant DNA contains a higher proportion of repetitive sequences and transposable elements, which are mobile genetic elements that can move around the genome and cause mutations. Additionally, plant cells have cell walls and chloroplasts, which are not present in animal cells, and these structures contain their own DNA.

A consensus sequence in genetics refers to the most common nucleotide (DNA or RNA) or amino acid at each position in a multiple sequence alignment. It is derived by comparing and analyzing several sequences of the same gene or protein from different individuals or organisms. The consensus sequence provides a general pattern or motif that is shared among these sequences and can be useful in identifying functional regions, conserved domains, or evolutionary relationships. However, it's important to note that not every sequence will exactly match the consensus sequence, as variations can occur naturally due to mutations or genetic differences among individuals.

'Euglena' is a genus of unicellular flagellate protists that are typically characterized by their oval-shaped bodies, long whip-like tail (flagellum), and eyespot (stigma) which helps them to move towards light. They are commonly found in freshwater environments and can also be found in soil and brackish water. Some species of Euglena have the ability to photosynthesize, while others obtain their nutrition through heterotrophy (consuming other organisms or organic matter). The term 'Euglena' is derived from the Greek word 'euglenes', which means "well-shaped" or "true-eyed". Medical professionals and researchers may study Euglena as part of broader research into protists, microbiology, or ecology.

Introns is a remix album by the American rock band LCD Soundsystem, released in March 2006 through DFA as a digital download. ...
... tRNA introns, group I introns, group II introns, and spliceosomal introns (see below). Introns are rare in Bacteria and Archaea ... and possibly to spliceosomal introns. Nuclear pre-mRNA introns (spliceosomal introns) are characterized by specific intron ... Intron transfer has been hypothesized to result in intron gain when a paralog or pseudogene gains an intron and then transfers ... This intron-containing mRNA is then reverse transcribed and the resulting intron-containing cDNA may then cause intron gain via ...
The Database for Bacterial Group II Introns is a repository of full-length, non-redundant group II introns present in bacterial ... group II intron Candales, Manuel A; Duong Adrian; Hood Keyar S; Li Tony; Neufeld Ryan A E; Sun Runda; McNeil Bonnie A; Wu Li; ... The database is first established in 2002 with roughly 40 introns. In less than 10 years, the database has expanded to 400 ... In addition, it contains a list of intron insertion sites, DNA sequences, protein-encoding sequences, as well as RNA secondary ...
The bZIP intron candida is an unconventional bZIP intron located in the HAC1 mRNA in a subgroup of fungi from Saccharomycetales ... Splicing performed by Ire1 results in excision of a very long intron that was first described in Candida parapsilosis. Hooks KB ... bZIP intron ascomycota-like). The consensus structure consists of two well conserved hairpins with loop regions defining the ... Griffiths-Jones S (2011). "Conserved RNA structures in the non-canonical Hac1/Xbp1 intron". RNA Biol. 8 (4): 552-556. doi: ...
... s identify introns along pre-tRNAs and carry out the proper excision mechanism to remove those introns ... tRNA-intron lyase (EC 4.6.1.16, tRNA intron endonuclease, transfer ribonucleate intron endoribonuclease, tRNA splicing ... and an intron with a 2',3'-cyclic phosphate and a 5'-hydroxyl terminus. The use of tRNA-intron endonuclease in pre-tRNA intron ... Splicing on both the 3' and 5' ends of the intron. tRNA-intron lyase requires a level of specificity to the splice site on the ...
The small T intron is an intron, that is used in some plasmid vectors, in order to induce gene expression in mammalian cells. ... The function of this intron in the vectors is unknown, but it is theorized that it might be involved in splicing or translation ... Hunt AG, Mogen BD, Chu NM, Chua NH (1991). "The SV40 small t intron is accurately and efficiently spliced in tobacco cells". ... Huang MT, Gorman CM (1990). "The simian virus 40 small-t intron, present in many common expression vectors, leads to aberrant ...
One feature of Intron Depot 1 is that all of the works are presented with a small aside from Shirow as to his thoughts on them ... Intron Depot 1 in two spots in particular is quite graphic. One panel involves a graphic drawing of a lesbian ménage à trois, ... Intron Depot 1 (イントロンデポ) is a collection of Masamune Shirow's full color works. The volume itself is 148 210 mm x 285 mm pages ... Everything from Appleseed to Orion are well represented in Intron Depot 1, some pictures are reproductions of paintings, others ...
The bZIP intron saccharomycetales is an unconventional bZIP intron located in the HAC1 mRNA in most budding yeast belonging to ... Hooks KB, Griffiths-Jones S (2011). "Conserved RNA structures in the non-canonical Hac1/Xbp1 intron". RNA Biol. 8 (4): 552-556 ...
The bZIP intron animal is an unconventional bZIP intron in animals located in the mRNA of Xbp1 orthologs. The RNA structure ... Intron is usually 23 or 26 nt long and it is excised by endoribonuclease Ire1 encoded by ERN1 gene in response to ER stress. ... Hooks KB, Griffiths-Jones S (2011). "Conserved RNA structures in the non-canonical Hac1/Xbp1 intron". RNA Biol. 8 (4): 552-556 ...
The bZIP intron plant is an unconventional bZIP intron in plants located in the mRNA of bZIP60 orthologs. The consensus RNA ... Majority of the plants contain also a nested spliceosomal intron located at the base of 3' hairpin. The unconventional splicing ... Hooks KB, Griffiths-Jones S (2011). "Conserved RNA structures in the non-canonical Hac1/Xbp1 intron". RNA Biol. 8 (4): 552-556 ... structure is very similar to the animal variant with short, usually 23 nt intron defined by the loop regions of the conserved ...
If the intron can no longer enhance expression, then inclusion of the intron in the transcript is important, and the intron ... is the ability of an intron sequence to enhance the expression of a gene containing that intron. In particular, the intron must ... The position of an intron within the transcript is also important - the closer an intron is to the start (5' end) of a ... Rose, Alan B. (2004-12-01). "The effect of intron location on intron-mediated enhancement of gene expression in Arabidopsis". ...
... (U12DB) is a biological database of containing the sequence of eukaryotic introns that are spliced out by a ... These U12-dependent introns are under-represented in genome annotations because they often have non canonical splice sites. ... Release 1 of the database contains 6,397 known and predicted U12-dependent introns across 20 species. Alioto, Tyler S (Jan 2007 ... "U12DB: a database of orthologous U12-type spliceosomal introns". Nucleic Acids Res. England. 35 (Database issue): D110-5. doi: ...
The bZIP intron ascomycota is an unconventional bZIP intron found in some of the Ascomycota fungi, mainly in filamentous fungi ... The unconventional splicing in this group results in excising introns of typical length 20 or 23 nt and it was first described ... Hooks KB, Griffiths-Jones S (2011). "Conserved RNA structures in the non-canonical Hac1/Xbp1 intron". RNA Biol. 8 (4): 552-556 ...
The bZIP intron basidiomycota is an unconventional bZIP intron found mainly in the Basidiomycota and some Mucoromycotina fungi ... In Basidiomycota, splicing results in excised introns from 20 to 101 nt in length and it was first described in Cryptococcus ... Hooks KB, Griffiths-Jones S (2011). "Conserved RNA structures in the non-canonical Hac1/Xbp1 intron". RNA Biol. 8 (4): 552-556 ...
... is a class of introns found in mRNA genes of chloroplasts in euglenid protists. They have a conventional group ... Group III introns are much shorter than other self-splicing intron classes, ranging from 95 to 110 nucleotides amongst those ... In 1994, discovery of a group III intron with a length of one order of magnitude longer indicated that length alone is not the ... In 1989, David A. Christopher and Richard B. Hallick found a few more examples and proposed the name "Group III introns" to ...
The Exon-Intron Database (EID) is a database of spliced mRNA sequences. Alternative splicing Exon Intron Saxonov, S; Daizadeh I ... Fedorov A; Gilbert W (Jan 2000). "EID: the Exon-Intron Database-an exhaustive database of protein-coding intron-containing ...
Database for bacterial group II introns Intron Splice site Nuclear introns Group I intron Group III intron Twintron LtrA ... Protein machinery is required for splicing in vivo, and long-range intron-intron and intron-exon interactions are important for ... The first intron to be identified as distinct from group I was the ai5γ group IIB intron, which was isolated in 1986 from a pre ... In contrast to group I introns, intron excision occurs in the absence of GTP and involves the formation of a lariat, with an A- ...
The consensus intron is very short in Metazoa (20, 23 or 26 nt). However, yeast species have a long (>100 nt) intron in HAC1. ... The bZIP intron RNA motif is an RNA structure guiding splicing of a non-canonical intron from bZIP-containing genes called HAC1 ... Recognition of the intron splice sites is mediated by a base-paired secondary structure of the mRNA that forms at the exon/ ... intron boundaries. Splicing of the bZIP intron is a key regulatory step in the unfolded protein response (UPR). The Ire- ...
Intron Group I Intron Sequence and Structure Database Splice site Nuclear introns Group II intron Group III intron Twintron ... Both intron-early and intron-late theories have found evidences in explaining the origin of group I introns. Some group I ... Group I introns often have long open reading frames inserted in loop regions. Splicing of group I introns is processed by two ... A small number of group I introns are also found to encode a class of proteins called maturases that facilitate the intron ...
Intron-encoded endonuclease I-Sce I is a homing endonuclease. The enzyme is used in biotechnology as a meganuclease. It ... I-SceI is coded by introns. It is present in the mitochondria of yeast Saccharomyces cerevisiae. New England Biolabs site ...
Jacquier A, Dujon B (June 1985). "An intron-encoded protein is active in a gene conversion process that spreads an intron into ... "Intron 5 alpha of the COXI gene of yeast mitochondrial DNA is a mobile group I intron". Nucleic Acids Res. 20 (15): 4069-76. ... "Structural conservation among three homologous introns of bacteriophage T4 and the group I introns of eukaryotes". PNAS. 85 (4 ... Eddy SR, Gold L (June 1991). "The phage T4 nrdB intron: a deletion mutant of a version found in the wild". Genes Dev. 5 (6): ...
Notches indicate introns. Chloroplast DNA (cpDNA) is the DNA located in chloroplasts, which are photosynthetic organelles ...
Introns and inteins. Intragenomic conflict: Homing endonuclease genes. I-CreI homing endonuclease. Databases and lists of ...
Notches indicate introns. Gene mapping or genome mapping describes the methods used to identify the location of a gene on a ...
Notches indicate introns. With few exceptions, most chloroplasts have their entire chloroplast genome combined into a single ... Unlike prokaryotic DNA molecules, chloroplast DNA molecules contain introns (plant mitochondrial DNAs do too, but not human ...
... contains 18 introns. There are 2 non overlapping alternative last exons. The transcripts appear to differ by truncation of ... MCM6 produces, by alternative splicing, 3 different transcripts, all with introns, putatively encoding 3 different protein ... located in two of the MCM6 introns, approximately 14 kb and 22 kb upstream of LCT. A substitution of thymine for cytosine in ...
Bürglin TR, Barnes TM (1992). "Introns in sequence tags". Nature. 357 (6377): 367-8. Bibcode:1992Natur.357..367B. doi:10.1038/ ...
De Souza, Sandro J.; Long, Manyuan; Gilbert, Walter (June 1996). "Introns and gene evolution". Genes to Cells. 1 (6): 493-505. ...
... s and viroids have been compared to circular introns due to their size similarity. It has been proposed that virusoids ... In particular, virusoids and viroids exhibit several structural and sequence homologies to the group I introns such as the self ... Dinter-Gottlieb, G (September 1986). "Viroids and virusoids are related to group I introns". Proceedings of the National ... Diener, T. O. (August 1981). "Are viroids escaped introns?". Proceedings of the National Academy of Sciences. 78 (8): 5014-5015 ...
When testing the effect of unc-5::intron::unc-5 transgene on a mislocalization defect in UNC-5 mutant animals at 25 °C a ...
Introns is a remix album by the American rock band LCD Soundsystem, released in March 2006 through DFA as a digital download. ...
Indication-specific dosing for Intron A, Interferon alfa-2b (interferon alfa 2b), frequency-based adverse effects, ... encoded search term (interferon alfa 2b (Intron A%2C Interferon alfa-2b)) and interferon alfa 2b (Intron A, Interferon alfa-2b) ... Intron A Solution for Injection not recommended for IV. SC Administration. SC administration is suggested for those who are at ... Discontinue Intron A for progressive disease or failure to respond after 6 mo of treatment ...
GO:0000213: tRNA-intron endonuclease activity (Molecular function). Catalysis of the endonucleolytic cleavage of pre-tRNA, ... producing 5-hydroxyl and 2,3-cyclic phosphate termini, and specifically removing the intron. [EC:3.1.27.9] ...
Interferon alfa 2b (Intron A). *View full drug information. IFN alfa-2b is a protein product manufactured by recombinant DNA ...
Splice out introns; small complexes of snRNPs, composed of proteins + snRNAs; enzymatic activity in RNA, NOT protein. ... Removal of section of primary transcript; called intron (, 10,000 bp long); retained regions = exons. ...
intron_variant. A transcript variant occurring within an intron.. splice_donor_variant. A splice variant that changes the 2- ... intron. splice site or splice region. exon of non-coding gene. "variants" for which no alternate allele has been observed. ... For example, a variant might be located in the coding sequence of one transcript, but in the intron of an alternatively spliced ... A transcript variant with a complex insertion or deletion (indel) that spans an exon/intron border or a coding sequence/UTR ...
A compound heterozygote in LYST gene, consisting of a missense mutation c.5719A , G and an intron mutation c.4863-4G , A, was ...
Intron A Immunotherapy Cytokine Interferon June 4, 1986 Oct. 3, 2010 No Longer Used ... Intron A Immunotherapy Cytokine Interferon June 4, 1986 Dec. 4, 2010 No Longer Used ... Intron A Immunotherapy Cytokine Interferon June 4, 1986 Dec. 12, 2010 No Longer Used ...
Human monoamine oxidase A and B genes exhibit identical exon-intron organization. Proc Natl Acad Sci U S A. 1991 May 1;88(9): ...
intron_variant. A transcript variant occurring within an intron.. splice_donor_variant. A splice variant that changes the 2- ... intron. splice site or splice region. exon of non-coding gene. "variants" for which no alternate allele has been observed. ... For example, a variant might be located in the coding sequence of one transcript, but in the intron of an alternatively spliced ... A transcript variant with a complex insertion or deletion (indel) that spans an exon/intron border or a coding sequence/UTR ...
Splicing that results in the removal of a 26 nt intron. PCR conditions were as follows: 1 hold 94°C for 4 min, 94°C 10 s, 63°C ...
Intron. A. A. G. G. G. T333544C. Intron. T. T. C. C. C. ... Intron. G. G. A. A. A. PVX_123230. T1257042C. P654. T. T. C. C ... Intron. G. G. A. A. A. A333518G. ... Intron. A. C. C. ND. C. G333391A. ... Intron. T. C. C. ND. C. A332874C. ... Intron. T. C. C. C. C. T332453C. ...
Evidence-Data-START## RNAseq introns :: mixed/partial sample support SAMD00052296, SAMD00052297 [ECO:0000350] ##Evidence-Data- ...
Intron Biotechnology (Intron Bio) is one of the leading patent filers in bacteriophage therapy. The drug development company ... In terms of application diversity, Intralytix leads the pack, while iNtRON Biotechnology and Micreos stood in the second and ...
DNA:SNP:intron 1: C>T. RGD. PMID:20117248. RGD:40818420. NCBI chr X:30,293,597...30,340,961 Ensembl chr X:30,293,589... ...
But its a lot more complicated than that, since genes often contain non-coding regions called introns and protein chains are ... https://en.wikipedia.org/wiki/Intron. Bottom line is that there are a lot more protein variants in a human cell than 20,000. ( ...
The Maxime RT PreMix KIT was obtained from iNtRON Biotechnology (iNtRON Biotechnology, Seoul, Korea). TRIzol reagent was ...
intron_variant. A transcript variant occurring within an intron.. splice_donor_variant. A splice variant that changes the 2- ... intron. splice site or splice region. exon of non-coding gene. "variants" for which no alternate allele has been observed. ... For example, a variant might be located in the coding sequence of one transcript, but in the intron of an alternatively spliced ... A transcript variant with a complex insertion or deletion (indel) that spans an exon/intron border or a coding sequence/UTR ...
Intron A, Roferon-A); ledipasvir/sofosbuvir (Harvoni); lopinavir/ritonavir (Kaletra); ribavirin (Copegus, Rebetol, Ribasphere ...
Unraveling the mechanism of recognition of the 3 splice site of the adenovirus major late promoter intron by the alternative ...
Intron 22 inversion (inv22) may account for 45% of all cases of severe haemophilia A. Haemophilia A is underdiagnosed in South ... Intron 22 inversion real-time polymerase chain reaction detection in haemophilia A families from central South Africa ... Intron 22 inversion real-time polymerase chain reaction detection in haemophilia A familie ...
None of the encoding genes was found to contain introns. The virion morphogenesis module in EMALE types 1 and 3-7 consists of ... Fifteen integration sites were located within a predicted host gene (13 in exons, 2 in introns), four were found in predicted 3 ...
Protocols with interferon (IFN) (Intron A) and other immunotherapies are common.. Multimodal therapy offers the best likelihood ...
A biological process in which introns are removed from RNA in different combinations to produce different mRNA molecules from ...
... intron 2: A case control study in an Italian population. BMC Cancer, 8, 138. doi: 10.1186/1471-2407-8-138 ...
These primers amplify approximately 495 bp of exons and introns at the 5 end of the β-tubulin gene. ...
Every pair of oligonucleotide primers was designed to amplify a region including at least 1 intron. The real-time PCR reaction ...
2008). Phylogeny of the beaked whale genus Mesoplodon (Ziphiidae: Cetacea) revealed by nuclear introns: implications for the ...
... iNtRON Biotechnology®). The ABI 3500 Genetic Analyzer sequencer (Applied Biosystems) was used, and the reactions were performed ...
  • Group II introns catalyze their own excision from pre-RNA by two consecutive transesterifications and concomitant splicing of the flanking exons. (schoolbag.info)
  • In 1982, however, Thomas R. Cech described the self splicing group I intron from the ciliated protozoon Tetrahymena thermophila, which can excise itself from pre-rRNA and join the flanking exons in vitro (1). (schoolbag.info)
  • In the second step of splicing, the 5'-exon terminus attacks the 3'-scissile phosphate, which results in spliced exons and a linear intron with a 5'-terminal guanosine. (schoolbag.info)
  • The trnL gene is part of trnL-F region of chloroplast genome that split by group I intron, the intergenic spacer and trnF exons (Figure 1) and is co-transcribed (Bakker et al. (environmentalistsforeurope.org)
  • These primers amplify approximately 495 bp of exons and introns at the 5' end of the β-tubulin gene. (cdc.gov)
  • The Ll.LtrB intron works very efficiently for gene targeting in bacteria, and it is desirable to target mammalian genomes, for which efficient means of manipulation are lacking. (utexas.edu)
  • With improvements in targeting efficiency, group II introns would be generally useful for functional genomics and gene therapy. (utexas.edu)
  • Introns are necessary for gene expression and alternative splicing can regulate gene expression in response to environmental cues. (pasteur.fr)
  • The co-occurrence of non-standard introns within the same gene discloses the possibility that introns may be gained simultaneously. (uni-bielefeld.de)
  • In this article, we discuss the growing evidence that these differences are subject to selection acting on introns depending on the biology of the organism and the gene involved. (edu.sa)
  • and (d) a 3'-flanking sequence wherein the intron (b) is not derived from the same gene as that from which either the promoter (a) or the protein-coding sequence (c) is derived and processes, vectors, hosts and uses involving such a construct to obtain inter alia an increase in the level of expression of the coding sequence. (epo.org)
  • The mouse histone H2a gene consists of an element that enables cytoplasmic build up of globin-like mRNA in the absence of introns by binding the cellular SR proteins SRp20 and 9G8 (33,34). (mdm2-inhibitors.com)
  • Regrettably, the precise mechanism by which these latter elements enable intron-independent gene manifestation is only beginning to become recognized (34). (mdm2-inhibitors.com)
  • To test the validity of this hypothesis, we examined here the effects of these numerous elements on stabilization, 3 end processing and cytoplasmic build up of transcripts synthesized from variants of the human being -globin gene comprising either no intron or only the globin gene's Torin 1 price 1st intron. (mdm2-inhibitors.com)
  • When the 1st intron of -globin was included in the gene, the PRE, PPE and CJE still enhanced stabilization, 3 end control and cytoplasmic build up of -globin-like mRNA, in some cases without excision of the APO-1 intron. (mdm2-inhibitors.com)
  • In Cryptococcus neoformans, nearly all genes are interrupted by small introns. (pasteur.fr)
  • Previous investigations have shown that, during metazoan radiation, the exon-intron patterns of serpin superfamily genes were subject to massive changes, in contrast to many other genes. (uni-bielefeld.de)
  • In two genes, cooccurrence of non-standard introns was observed, implying that intron gains in vertebrates may even happen concomitantly or in a rapidly consecutive manner. (uni-bielefeld.de)
  • Conclusion: Multiple intron acquisitions were identified in serpin genes of a lineage of ray-finned fishes, but not in any other vertebrates, suggesting that insertion rates for introns may be episodically increased. (uni-bielefeld.de)
  • In the present study, we identified a homozygous mutation in the intron 1 of Wnt1 via large-scale screening of ASD risk/causative genes and verified that this mutation created a new splicing donor site in the intron 1, and consequently, a decrease of WNT1 expression. (harvard.edu)
  • Most mRNA-encoding genes require introns for efficient appearance in high eukaryotes. (mdm2-inhibitors.com)
  • Given that the CTE and RRE are naturally located in intron-containing genes while the PRE and PPE are naturally located in intronless genes, we hypothesized that CTE-like elements from intron-containing genes may not provide all the same functions as do PPE-like elements from intronless ones. (mdm2-inhibitors.com)
  • We conclude that while CTE-like elements enhance nucleocytoplasmic export with the introns in these genes facilitating appropriate 3 end formation, PPE-like elements from naturally intronless genes facilitate both these important methods in mRNA biogenesis regardless of the presence of introns. (mdm2-inhibitors.com)
  • Unraveling the mechanism of recognition of the 3' splice site of the adenovirus major late promoter intron by the alternative splicing factor PUF60. (bvsalud.org)
  • Group II introns are both catalytic RNAs and retrotransposable elements. (utexas.edu)
  • Our findings show that the association between nascent RNA and splicing factors in the nucleus is intron-dependent when the RNAs are either transiently or stably expressed. (cshl.edu)
  • Group II intron-encoded proteins (IEPs) have maturase activity, which promotes intron RNA splicing, and reverse transcriptase activity, which functions in intron mobility. (utexas.edu)
  • In vivo, group II intron splicing is generally assisted by proteins. (schoolbag.info)
  • With the help of proteins, some group II introns can also reverse the splicing reaction and integrate themselves into target genomes;this process resembles transposition of non-LTR retrotransposons and can be exploited for biotechnological applications. (schoolbag.info)
  • The sequences flanking the intron insertion points correspond to the proto-splice site consensus sequence MAG↑N, previously proposed to serve as intron insertion site. (uni-bielefeld.de)
  • These ribozymes are noncoding intervening sequences (introns) that can catalyze their own excision from the parent pre-RNA. (schoolbag.info)
  • However, recent studies have shown that some eukaryotes lost many introns, whereas others accumulated and/or gained many introns. (edu.sa)
  • More recently, a group II intron was found in a primitive metazoan. (schoolbag.info)
  • I developed E. coli genetic assays to detect in vivo splicing of the Ll.LtrB intron and identify regions in the IEP essential for interacting with different parts of the intron RNA. (utexas.edu)
  • I developed an expression system to produce Ll.LtrB intron RNA and IEP in cultured human cells and found that the expressed intron splices in vivo. (utexas.edu)
  • The brown algae Pl.LSU/2 group II intron-encoded protein has functional reverse transcriptase and maturase activities. (genethon.com)
  • In recent years, genome annotation and genetic analysis have illuminated the major roles these introns play in the biology of this pathogenic yeast. (pasteur.fr)
  • In addition, recent studies have revealed that C. neoformans introns help to prevent transposon dissemination and protect genome integrity. (pasteur.fr)
  • DNA breakage/repair processes associated with genome compaction are introduced as a novel factor potentially favoring intron gain, since all non-canonical introns were found in a lineage of ray-finned fishes that experienced genomic downsizing. (uni-bielefeld.de)
  • The association of intron gains in the serpin superfamily with a group of fishes that underwent genome compaction may indicate that DNA breakage/repair processes might foster intron birth. (uni-bielefeld.de)
  • MPMV's CTE, HBV's PRE, HSV-TK's PPE and HIV-1's RRE in the presence of Rev all enhance efficient nuclear export of mRNA without splicing in an intron-containing reporter derived from the HIV-1 genome (32,39). (mdm2-inhibitors.com)
  • Here, we modeled the molecular structure of the ai5γ group IIB intron from yeast using the crystal structure of a bacterial group IIC homolog. (nih.gov)
  • These characteristics of cryptococcal introns are probably not unique to Cryptococcus, and this yeast likely can be considered as a model for intron-related studies in fungi. (pasteur.fr)
  • Phylogeny and self-splicing ability of the plastid tRNA-Leu group I Intron. (nih.gov)
  • Multiple intron gains were detected in a group of ray-finned fishes, once the canonical groups of vertebrate serpins had been established. (uni-bielefeld.de)
  • The self-splicing group II introns are among the largest naturally occurring ribozymes and have been found primarily in organellar genomes of plants, fungi, bacteria, proteobacteria, and blue algae. (schoolbag.info)
  • More than 200 different group II introns have been identified to date. (schoolbag.info)
  • All group II introns have a conserved secondary structure composed of six stem-loop structures termed domains D1 -D6, which are arranged around a central wheel and provide distinct contributions to intron function. (schoolbag.info)
  • Intriguingly, group II introns share several mechanistic and structural features with the eukaryotic spliceosome, which suggests an evolutionary relationship. (schoolbag.info)
  • Two groups of self-splicing ribozymes exist: the group I and group II introns. (schoolbag.info)
  • They can be very large with sizes of 200-1500 nucleotides (group I introns) and 400-2500 nucleotides (group II introns). (schoolbag.info)
  • In group I introns, the attacking nucleophile in the first step is the 3'-OH group of an external guanosine (Fig. 1c). (schoolbag.info)
  • In group II introns, the attacking nucleophile in the first step is either the 2'-OH group of an adenosine located close to the intron terminus (Fig. 1d) or a water molecule (analogous to Fig. 1b). (schoolbag.info)
  • Thermostable group II intron reverse transcriptase (TGIRTTM) enzymes and methods for their use are the subject of patents and patent applications that have been licensed by the University of Texas at Austin and East Tennessee State University to InGex, LLC. (cdc.gov)
  • Previous studies of the Lactococcus lactis Ll.LtrB intron suggested a model in which its IEP binds first to a high-affinity binding site in intron subdomain DIVa and then makes additional contacts with the conserved catalytic core to stabilize the active RNA structure. (utexas.edu)
  • II intron reverse transcriptase to overcome these obstacles (DM-TGIRT-seq). (cdc.gov)
  • Background: Intron gains reportedly are very rare during evolution of vertebrates, and the mechanisms underlying their creation are largely unknown. (uni-bielefeld.de)
  • Intron density in eukaryote genomes varies by more than three orders of magnitude, so there must have been extensive intron gain and/or intron loss during evolution. (edu.sa)
  • Is the Subject Area "Introns" applicable to this article? (plos.org)
  • Under the terms of the agreement, iNtRON Bio will receive an upfront payment upon execution of the agreement and subsequent milestone payments for development, regulatory, and sales-driven events. (pharmafocusasia.com)
  • A favored and partial explanation for this range of intron densities has been that introns have accumulated stochastically in large eukaryote genomes during their evolution from an intron-poor ancestor. (edu.sa)
  • Results: Here we investigated intron dynamics in the serpin superfamily in lineages pre- and postdating the split of vertebrates. (uni-bielefeld.de)
  • We have examined the nuclear localization of transiently and stably expressed nascent RNA transcripts containing or lacking introns in order to determine if the spatial association of RNA transcripts and pre-mRNA splicing factors in nuclei is random or functionally significant. (cshl.edu)
  • If necessary, the forward primer, ITS1 [5], may be used with NLB4 as an alternative since this non-specific primer is downstream of the intron and can be used to avoid amplifying the intron. (environmentalistsforeurope.org)
  • Introns is a remix album by the American rock band LCD Soundsystem, released in March 2006 through DFA as a digital download. (wikipedia.org)