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.
Highly repeated sequences, 6K-8K base pairs in length, which contain RNA polymerase II promoters. They also have an open reading frame that is related to the reverse transcriptase of retroviruses but they do not contain LTRs (long terminal repeats). Copies of the LINE 1 (L1) family form about 15% of the human genome. The jockey elements of Drosophila are LINEs.
Nucleotide sequences repeated on both the 5' and 3' ends of a sequence under consideration. For example, the hallmarks of a transposon are that it is flanked by inverted repeats on each end and the inverted repeats are flanked by direct repeats. The Delta element of Ty retrotransposons and LTRs (long terminal repeats) are examples of this concept.
Highly repeated sequences, 100-300 bases long, which contain RNA polymerase III promoters. The primate Alu (ALU ELEMENTS) and the rodent B1 SINEs are derived from 7SL RNA, the RNA component of the signal recognition particle. Most other SINEs are derived from tRNAs including the MIRs (mammalian-wide interspersed repeats).
A species of migratory Old World locusts, in the family ACRIDIDAE, that are important pests in Africa and Asia.
A family of DNA plant viruses with isometric or bacilliform virions and no envelope. The host ranges of most species are narrow. There are six genera: CAULIMOVIRUS; BADNAVIRUS; Cavemovirus; Soymovirus; Petuvirus; and TUNGROVIRUS.
Retroviruses that have integrated into the germline (PROVIRUSES) that have lost infectious capability but retained the capability to transpose.
The Alu sequence family (named for the restriction endonuclease cleavage enzyme Alu I) is the most highly repeated interspersed repeat element in humans (over a million copies). It is derived from the 7SL RNA component of the SIGNAL RECOGNITION PARTICLE and contains an RNA polymerase III promoter. Transposition of this element into coding and regulatory regions of genes is responsible for many heritable diseases.
An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC 2.7.7.49.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
The relationships of groups of organisms as reflected by their genetic makeup.
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.
An enzyme which catalyzes the deamination of CYTOSINE resulting in the formation of URACIL. It can also act on 5-methylcytosine to form THYMIDINE.
An enzyme that catalyzes the deamination of cytidine, forming uridine. EC 3.5.4.5.
A genus of Old World monkeys of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, that inhabits the mountainous regions of Ethiopia. The genus consists of only one species, Theropithecus gelada.
Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).
Copies of DNA sequences which lie adjacent to each other in the same orientation (direct tandem repeats) or in the opposite direction to each other (INVERTED TANDEM REPEATS).
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A diverse genus of minute freshwater CRUSTACEA, of the suborder CLADOCERA. They are a major food source for both young and adult freshwater fish.
The genetic complement of a plant (PLANTS) as represented in its DNA.
Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
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.
Deoxyribonucleic acid that makes up the genetic material of plants.
Genes of IAP elements (a family of retrovirus-like genetic elements) which code for virus-like particles (IAPs) found regularly in rodent early embryos. ("Intracisternal" refers to the cisternae of the endoplasmic reticulum.) Under certain circumstances, such as DNA hypomethylation they are transcribed. Their transcripts are found in a variety of neoplasms, including plasmacytomas, neuroblastoma, rhabdomyosarcomas, teratocarcinomas, and colon carcinomas.
DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.
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).
Cells lacking a nuclear membrane so that the nuclear material is either scattered in the cytoplasm or collected in a nucleoid region.
The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.
DNA sequences that form the coding region for retroviral enzymes including reverse transcriptase, protease, and endonuclease/integrase. "pol" is short for polymerase, the enzyme class of reverse transcriptase.
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.
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).
'Primates' is a taxonomic order comprising various species of mammals, including humans, apes, monkeys, and others, distinguished by distinct anatomical and behavioral characteristics such as forward-facing eyes, grasping hands, and complex social structures.
Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.
The biosynthesis of DNA carried out on a template of RNA.
Proteins from the family Retroviridae. The most frequently encountered member of this family is the Rous sarcoma virus protein.
Highly repetitive DNA sequences found in HETEROCHROMATIN, mainly near centromeres. They are composed of simple sequences (very short) (see MINISATELLITE REPEATS) repeated in tandem many times to form large blocks of sequence. Additionally, following the accumulation of mutations, these blocks of repeats have been repeated in tandem themselves. The degree of repetition is on the order of 1000 to 10 million at each locus. Loci are few, usually one or two per chromosome. They were called satellites since in density gradients, they often sediment as distinct, satellite bands separate from the bulk of genomic DNA owing to a distinct BASE COMPOSITION.
Cells of the higher organisms, containing a true nucleus bounded by a nuclear membrane.
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 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.
A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.
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.
Duplex DNA sequences in eukaryotic chromosomes, corresponding to the genome of a virus, that are transmitted from one cell generation to the next without causing lysis of the host. Proviruses are often associated with neoplastic cell transformation and are key features of retrovirus biology.
The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.
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 portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.
The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
The sequential location of genes on a chromosome.
Addition of methyl groups to DNA. DNA methyltransferases (DNA methylases) perform this reaction using S-ADENOSYLMETHIONINE as the methyl group donor.
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 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.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Facilities equipped to carry out investigative procedures.
The functional hereditary units of PLANTS.
A terminal section of a chromosome which has a specialized structure and which is involved in chromosomal replication and stability. Its length is believed to be a few hundred base pairs.
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.
Any method used for determining the location of and relative distances between genes on a chromosome.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
Genotypic differences observed among individuals in a population.
A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
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)
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
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.
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.
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.
Deoxyribonucleic acid that makes up the genetic material of fungi.
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.
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.
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.

Loss-of-function mutations in the rice homeobox gene OSH15 affect the architecture of internodes resulting in dwarf plants. (1/1835)

The rice homeobox gene OSH15 (Oryza sativa homeobox) is a member of the knotted1-type homeobox gene family. We report here on the identification and characterization of a loss-of-function mutation in OSH15 from a library of retrotransposon-tagged lines of rice. Based on the phenotype and map position, we have identified three independent deletion alleles of the locus among conventional morphological mutants. All of these recessive mutations, which are considered to be null alleles, exhibit defects in internode elongation. Introduction of a 14 kbp genomic DNA fragment that includes all exons, introns and 5'- and 3'- flanking sequences of OSH15 complemented the defects in internode elongation, confirming that they were caused by the loss-of-function of OSH15. Internodes of the mutants had abnormal-shaped epidermal and hypodermal cells and showed an unusual arrangement of small vascular bundles. These mutations demonstrate a role for OSH15 in the development of rice internodes. This is the first evidence that the knotted1-type homeobox genes have roles other than shoot apical meristem formation and/or maintenance in plant development.  (+info)

A new member of the Sin3 family of corepressors is essential for cell viability and required for retroelement propagation in fission yeast. (2/1835)

Tf1 is a long terminal repeat (LTR)-containing retrotransposon that propagates within the fission yeast Schizosaccharomyces pombe. LTR-retrotransposons possess significant similarity to retroviruses and therefore serve as retrovirus models. To determine what features of the host cell are important for the proliferation of this class of retroelements, we screened for mutations in host genes that reduced the transposition activity of Tf1. We report here the isolation and characterization of pst1(+), a gene required for Tf1 transposition. The predicted amino acid sequence of Pst1p possessed high sequence homology with the Sin3 family of proteins, known for their interaction with histone deacetylases. However, unlike the SIN3 gene of Saccharomyces cerevisiae, pst1(+) is essential for cell viability. Immunofluorescence microscopy indicated that Pst1p was localized in the nucleus. Consistent with the critical role previously reported for Sin3 proteins in the histone acetylation process, we found that the growth of the strain with the pst1-1 allele was supersensitive to the specific histone deacetylase inhibitor trichostatin A. However, our analysis of strains with the pst1-1 mutation was unable to detect any changes in the acetylation of specific lysines of histones H3 and H4 as measured in bulk chromatin. Interestingly, the pst1-1 mutant strain produced wild-type levels of Tf1-encoded proteins and cDNA, indicating that the defect in transposition occurred after reverse transcription. The results of immunofluorescence microscopy showed that the nuclear localization of the Tf1 capsid protein was disrupted in the strain with the pst1-1 mutation, indicating an important role of pst1(+) in modulating the nuclear import of Tf1 virus-like particles.  (+info)

Nonmethylated transposable elements and methylated genes in a chordate genome. (3/1835)

The genome of the invertebrate chordate Ciona intestinalis was found to be a stable mosaic of methylated and nonmethylated domains. Multiple copies of an apparently active long terminal repeat retrotransposon and a long interspersed element are nonmethylated and a large fraction of abundant short interspersed elements are also methylation free. Genes, by contrast, are predominantly methylated. These data are incompatible with the genome defense model, which proposes that DNA methylation in animals is primarily targeted to endogenous transposable elements. Cytosine methylation in this urochordate may be preferentially directed to genes.  (+info)

Retrotransposons transcribed preferentially in proximal tubules of salt-hypertensive rats. (4/1835)

BACKGROUND: The kidney is considered to play an important etiologic role in salt-sensitive hypertension. The aim of the present study was to isolate genes whose expression differs between the kidneys of salt-hypertensive and control rats using an mRNA differential display method. METHODS: Dahl salt-sensitive (DS) and control salt-resistant rats (DR) were fed a 0.3% or 8% NaCl diet. Renal RNA was amplified by RNA arbitrarily primed polymerase chain reaction (RAP-PCR) and compared among DR 0.3%, DR 8%, DS 0.3%, and DS 8%. Gene expression and localization were examined by Northern blotting, RNase protection assay, and in situ hybridization. Full-length nucleotide sequence was determined by screening a DS rat kidney cDNA library. RESULTS: We identified one differentially displayed clone, and its expression was greater in DS than DR, which was not affected by salt loading. The sequence was 90% homologous to the 3'-noncoding region of the nicotinic acetylcholine receptor alpha7 subunit gene. Its expression was kidney-specific, and was localized in the proximal tubules. The transcript level was markedly increased precedent to the development of hypertension. Its expression was also high in other salt-sensitive rats, and low in normotensive Sprague-Dawley and Wistar rats. The full-length cDNA contained elements homologous to the retroviral pol gene, a primer binding site sequence for reverse transcriptase, and long-terminal repeats. CONCLUSION: These results demonstrated that the newly identified transcripts (REPT1) belong to a novel retrotransposon family, which showed unique strain-, age-, tissue-, and cell type-specific expression pattern.  (+info)

Evolutionary dynamics of Ty1-copia group retrotransposons in grass shown by reverse transcriptase domain analysis. (5/1835)

The evolutionary dynamics of Ty1-copia group retrotransposons in grass were examined by reverse transcriptase (RT) domain analysis. Twenty-three rice RT sequences were newly determined for this report. Phylogenetic analysis of 177 RT sequences, mostly derived from wheat, rice, and, maize, showed four distinct families, which were designated G1, G2, G3, and G4. Three of these families have elements obtained from distantly related species, indicative of origins prior to the radiation of grass species. Results of Southern hybridization and detailed comparisons between the wheat and rice sequences indicated that each of the families had undergone a distinct pattern of evolution. Multiple families appear to have evolved in parallel in a host species. Analyses of synonymous and nonsynonymous substitutions suggested that there is a low percentage of elements carrying functional RT domains in the G4 family, indicating that the production of new G4 elements has been controlled by a small number of elements carrying functional RT domains.  (+info)

Inheritance of nuclear DNA markers in gynogenetic haploid pink salmon. (6/1835)

We describe the inheritance of 460 PCR-based loci in the polyploid-derived pink salmon (Oncorhynchus gorbuscha) genome using gynogenetic haploid embryos. We detected a length polymorphism in a growth hormone gene (GH-2) intron that is caused by an 81 bp insertion homologous to the 3' end of the salmonid short interspersed repetitive element (SINE) SmaI. Such insertion polymorphisms within species bring into question the use of SINEs as phylogenetic markers. We confirmed that a microsatellite locus encodes a PCR-null allele that is responsible for an apparent deficit of heterozygotes in a population sample from Prince William Sound. Another set of microsatellite primers amplified alleles of the same molecular weight from both loci of a duplicated pair. In our analysis of several PCR-based multilocus techniques, we failed to detect evidence of comigrating fragments produced by duplicated loci. Segregation analysis of PCR-based markers using gynogenetic haploid embryos ensures that the interpretation of molecular variation is not complicated by heterozygosity, diploidy, or gene duplication. We urge investigators to test the inheritance of polymorphisms in salmonids prior to using them to measure genetic variation.  (+info)

Mutagenic analysis of the 3' cis-acting elements of the rubella virus genome. (7/1835)

Thermodynamically predicted secondary structure analysis of the 3'-terminal 305 nucleotides (nt) of the rubella virus (RUB) genome, a region conserved in all RUB defective interfering RNAs, revealed four stem-loop (SL) structures; SL1 and SL2 are both located in the E1 coding region, while SL3 and SL4 are within the 59-nt 3' untranslated region (UTR) preceding the poly(A) tract. SL2 is a structure shown to interact with human calreticulin (CAL), an autoantigen potentially involved in RUB RNA replication and pathogenesis. RNase mapping indicated that SL2 and SL3 are in equilibrium between two conformations, in the second of which the previously proposed CAL binding site in SL2, a U-U bulge, is not formed. Site-directed mutagenesis of the 3' UTR with a RUB infectious clone, Robo302, revealed that most of the 3' UTR is required for viral viability except for the 3'-terminal 5 nt and the poly(A) tract, although poly(A) was rapidly regenerated during subsequent replication. Maintenance of the overall SL3 structure, the 11-nt single-stranded sequence between SL3 and SL4, and the sequences forming SL4 were all important for viral viability. Studies on the interaction between host factors and the 3' UTR showed the formation of three RNA-protein complexes by gel mobility shift assay, and UV-induced cross-linking detected six host protein species, with molecular masses of 120, 80, 66, 55, 48, and 36 kDa, interacting with the 3' UTR. Site-directed mutagenesis of SL2 by nucleotide substitutions showed that maintenance of SL2 stem rather than the U-U bulge was critical in CAL binding since mutants having the U-U bulge base paired had a similar binding activity for CAL as the native structure whereas mutants having the SL2 stem destabilized had much lower binding activity. However, all of these mutations gave rise to viable viruses when introduced into Robo302, indicating that binding of CAL to SL2 is independent of viral viability.  (+info)

A novel human DNA-binding protein with sequence similarity to a subfamily of redox proteins which is able to repress RNA-polymerase-III-driven transcription of the Alu-family retroposons in vitro. (8/1835)

In this study we identified a novel protein which may contribute to the transcriptional inactivity of Alu retroposons in vivo. A human cDNA clone encoding this protein (ACR1) was isolated from a human expression library using South-western screening with an Alu subfragment, implicated in the regulation of Alu in vitro transcription and interacting with a HeLa nuclear protein down-regulated in adenovirus-infected cells. Bacterially expressed ACR1 is demonstrated to inhibit RNA polymerase III (Pol III)-dependent Alu transcription in vitro but showed no repression of transcription of a tRNA gene or of a reporter gene under control of a Pol II promoter. ACR1 mRNA is also found to be down-regulated in adenovirus-infected HeLa cells, consistent with a possible repressor function of the protein in vivo. ACR1 is mainly (but not exclusively) located in cytoplasm and appears to be a member of a weakly characterized redox protein family having a central, highly conserved sequence motif, PGAFTPXCXXXXLP. One member of the family identified earlier as peroxisomal membrane protein (PMP)20 is known to interact in a sequence-specific manner with a yeast homolog of mammalian cyclosporin-A-binding protein cyclophilin, and mammalian cyclophilin A (an abundant ubiquitously expressed protein) is known to interact with human transcriptional repressor YY1, which is a major sequence-specific Alu-binding protein in human cells. It appears, therefore, that transcriptional silencing of Alu in vivo is a result of complex interactions of many proteins which bind to its Pol III promoter.  (+info)

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.

Long Interspersed Nucleotide Elements (LINEs) are a type of mobile genetic element, also known as transposable elements or retrotransposons. They are long stretches of DNA that are interspersed throughout the genome and have the ability to move or copy themselves to new locations within the genome. LINEs are typically several thousand base pairs in length and make up a significant portion of many eukaryotic genomes, including the human genome.

LINEs contain two open reading frames (ORFs) that encode proteins necessary for their own replication and insertion into new locations within the genome. The first ORF encodes a reverse transcriptase enzyme, which is used to make a DNA copy of the LINE RNA after it has been transcribed from the DNA template. The second ORF encodes an endonuclease enzyme, which creates a break in the target DNA molecule at the site of insertion. The LINE RNA and its complementary DNA (cDNA) copy are then integrated into the target DNA at this break, resulting in the insertion of a new copy of the LINE element.

LINEs can have both positive and negative effects on the genomes they inhabit. On one hand, they can contribute to genomic diversity and evolution by introducing new genetic material and creating genetic variation. On the other hand, they can also cause mutations and genomic instability when they insert into or near genes, potentially disrupting their function or leading to aberrant gene expression. As a result, LINEs are carefully regulated and controlled in the cell to prevent excessive genomic disruption.

Terminal repeat sequences (TRS) are repetitive DNA sequences that are located at the termini or ends of chromosomes, plasmids, and viral genomes. They play a significant role in various biological processes such as genome replication, packaging, and integration. In eukaryotic cells, telomeres are the most well-known TRS, which protect the chromosome ends from degradation, fusion, and other forms of DNA damage.

Telomeres consist of repetitive DNA sequences (5'-TTAGGG-3' in vertebrates) that are several kilobases long, associated with a set of shelterin proteins that protect them from being recognized as double-strand breaks by the DNA repair machinery. With each cell division, telomeres progressively shorten due to the end replication problem, which can ultimately lead to cellular senescence or apoptosis.

In contrast, prokaryotic TRS are often found at the ends of plasmids and phages and are involved in DNA replication, packaging, and integration into host genomes. For example, the attP and attB sites in bacteriophage lambda are TRS that facilitate site-specific recombination during integration and excision from the host genome.

Overall, terminal repeat sequences are essential for maintaining genome stability and integrity in various organisms, and their dysfunction can lead to genomic instability, disease, and aging.

Short Interspersed Nucleotide Elements (SINEs) are a type of transposable element in the genome. They are short sequences of DNA, typically around 100-300 base pairs in length, that are interspersed throughout the non-coding regions of the genome. SINEs are derived from small RNA genes, such as tRNAs and 7SL RNA, and are copied and inserted into new locations in the genome through a process called retrotransposition.

SINEs are usually non-coding and do not contain any known functional elements, but they can have regulatory effects on gene expression by affecting chromatin structure and transcription factor binding. They can also contribute to genetic diversity and evolution by creating new mutations and genomic rearrangements. However, the insertion of SINEs into genes or regulatory regions can also cause genetic diseases and cancer.

SINEs are one of the most abundant types of transposable elements in mammalian genomes, accounting for a significant fraction of the non-coding DNA. They are particularly enriched in the brain, suggesting a possible role in neural function and evolution.

"Locusta migratoria" is the scientific name for the migratory locust, which is a species of short-horned grasshopper. While it is not a medical term, I can provide some general information about this insect.

Migratory locusts are known for their ability to form large swarms that can travel long distances, consuming vast amounts of vegetation and causing significant damage to crops and pastures. They are native to Africa, Asia, and Europe but have been introduced to other parts of the world as well. The migratory locust is a agricultural pest and can pose a serious threat to food security in areas where they occur in large numbers.

From a medical perspective, some species of grasshoppers, including the migratory locust, can carry various pathogens that may affect humans and animals if ingested or come into contact with mucous membranes. However, there are no specific medical concerns associated with "Locusta migratoria" itself.

Caulimoviridae is a family of viruses that infect plants. These viruses have double-stranded DNA genomes and are transmitted through vegetative propagation or by insects. The family includes important plant pathogens such as cauliflower mosaic virus, carnation etched ring virus, and figwort mosaic virus. Infections with Caulimoviridae can cause a range of symptoms in plants, including stunting, mosaic patterns on leaves, and deformities in flowers and fruits.

Endogenous retroviruses (ERVs) are DNA sequences that have integrated into the genome of germ cells and are therefore passed down from parent to offspring through generations. These sequences are the remnants of ancient retroviral infections, where the retrovirus has become a permanent part of the host's genetic material.

Retroviruses are RNA viruses that replicate by reverse transcribing their RNA genome into DNA and integrating it into the host cell's genome. When this integration occurs in the germ cells, the retroviral DNA becomes a permanent part of the host organism's genome and is passed down to future generations.

Over time, many ERVs have accumulated mutations that render them unable to produce infectious viral particles. However, some ERVs remain capable of producing functional viral proteins and RNA, and may even be able to produce infectious viral particles under certain conditions. These active ERVs can play a role in various biological processes, both beneficial and detrimental, such as regulating gene expression, contributing to genome instability, and potentially causing disease.

It is estimated that up to 8% of the human genome consists of endogenous retroviral sequences, making them an important component of our genetic makeup.

Alu elements are short, repetitive sequences of DNA that are found in the genomes of primates, including humans. These elements are named after the restriction enzyme Alu, which was used to first identify them. Alu elements are derived from a 7SL RNA molecule and are typically around 300 base pairs in length. They are characterized by their ability to move or "jump" within the genome through a process called transposition.

Alu elements make up about 11% of the human genome and are thought to have played a role in shaping its evolution. They can affect gene expression, regulation, and function, and have been associated with various genetic disorders and diseases. Additionally, Alu elements can also serve as useful markers for studying genetic diversity and evolutionary relationships among primates.

RNA-directed DNA polymerase is a type of enzyme that can synthesize DNA using an RNA molecule as a template. This process is called reverse transcription, and it is the mechanism by which retroviruses, such as HIV, replicate their genetic material. The enzyme responsible for this reaction in retroviruses is called reverse transcriptase.

Reverse transcriptase is an important target for antiretroviral therapy used to treat HIV infection and AIDS. In addition to its role in viral replication, RNA-directed DNA polymerase also has applications in molecular biology research, such as in the production of complementary DNA (cDNA) copies of RNA molecules for use in downstream applications like cloning and sequencing.

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.

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 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.

Cytosine deaminase is an enzyme that catalyzes the hydrolytic deamination of cytosine residues in DNA or deoxycytidine residues in RNA, converting them to uracil or uridine, respectively. This enzyme plays a role in the regulation of gene expression and is also involved in the defense against viral infections in some organisms. In humans, cytosine deamination in DNA can lead to mutations and has been implicated in the development of certain diseases, including cancer.

Cytidine deaminase is an enzyme that catalyzes the removal of an amino group from cytidine, converting it to uridine. This reaction is part of the process of RNA degradation and also plays a role in the immune response to viral infections.

Cytidine deaminase can be found in various organisms, including bacteria, humans, and other mammals. In humans, cytidine deaminase is encoded by the APOBEC3 gene family, which consists of several different enzymes that have distinct functions and expression patterns. Some members of this gene family are involved in the restriction of retroviruses, such as HIV-1, while others play a role in the regulation of endogenous retroelements and the modification of cellular RNA.

Mutations in cytidine deaminase genes have been associated with various diseases, including cancer and autoimmune disorders. For example, mutations in the APOBEC3B gene have been linked to an increased risk of breast cancer, while mutations in other members of the APOBEC3 family have been implicated in the development of lymphoma and other malignancies. Additionally, aberrant expression of cytidine deaminase enzymes has been observed in some autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, suggesting a potential role for these enzymes in the pathogenesis of these conditions.

"Theropithecus" is a genus of Old World monkeys that includes the extinct species "Theropithecus oswaldi" and the currently existing species "Theropithecus gelada." These monkeys are native to Africa and are known for their distinctive long, pointed canines in males. The term "Theropithecus" comes from the Greek words "ther," meaning beast, and "pithekos," meaning ape.

It is important to note that "Theropithecus" species are not to be confused with "Theropoda," which is a group of dinosaurs that includes modern birds and their extinct relatives. The similarity in the names is purely coincidental.

Retroviridae is a family of viruses that includes human immunodeficiency virus (HIV) and other viruses that primarily use RNA as their genetic material. The name "retrovirus" comes from the fact that these viruses reverse transcribe their RNA genome into DNA, which then becomes integrated into the host cell's genome. This is a unique characteristic of retroviruses, as most other viruses use DNA as their genetic material.

Retroviruses can cause a variety of diseases in animals and humans, including cancer, neurological disorders, and immunodeficiency syndromes like AIDS. They have a lipid membrane envelope that contains glycoprotein spikes, which allow them to attach to and enter host cells. Once inside the host cell, the viral RNA is reverse transcribed into DNA by the enzyme reverse transcriptase, which is then integrated into the host genome by the enzyme integrase.

Retroviruses can remain dormant in the host genome for extended periods of time, and may be reactivated under certain conditions to produce new viral particles. This ability to integrate into the host genome has also made retroviruses useful tools in molecular biology, where they are used as vectors for gene therapy and other genetic manipulations.

Tandem Repeat Sequences (TRS) in genetics refer to repeating DNA sequences that are arranged directly after each other, hence the term "tandem." These sequences consist of a core repeat unit that is typically 2-6 base pairs long and is repeated multiple times in a head-to-tail fashion. The number of repetitions can vary between individuals and even between different cells within an individual, leading to genetic heterogeneity.

TRS can be classified into several types based on the number of repeat units and their stability. Short Tandem Repeats (STRs), also known as microsatellites, have fewer than 10 repeats, while Minisatellites have 10-60 repeats. Variations in the number of these repeats can lead to genetic instability and are associated with various genetic disorders and diseases, including neurological disorders, cancer, and forensic identification.

It's worth noting that TRS can also occur in protein-coding regions of genes, leading to the production of repetitive amino acid sequences. These can affect protein structure and function, contributing to disease phenotypes.

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.

'Daphnia' is not a medical term, but rather it refers to a group of small, planktonic crustaceans commonly known as water fleas. They are widely distributed in various freshwater environments and play an important role in the aquatic food chain as they serve as a food source for many larger animals such as fish.

While Daphnia may not have a direct medical definition, there has been some research into their potential use in biomedical applications due to their sensitivity to environmental changes. For instance, they have been used as indicators of water quality and toxicity levels in ecotoxicological studies. However, it is important to note that Daphnia itself is not a medical term or concept.

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.

Insertional mutagenesis is a process of introducing new genetic material into an organism's genome at a specific location, which can result in a change or disruption of the function of the gene at that site. This technique is often used in molecular biology research to study gene function and regulation. The introduction of the foreign DNA is typically accomplished through the use of mobile genetic elements, such as transposons or viruses, which are capable of inserting themselves into the genome.

The insertion of the new genetic material can lead to a loss or gain of function in the affected gene, resulting in a mutation. This type of mutagenesis is called "insertional" because the mutation is caused by the insertion of foreign DNA into the genome. The effects of insertional mutagenesis can range from subtle changes in gene expression to the complete inactivation of a gene.

This technique has been widely used in genetic research, including the study of developmental biology, cancer, and genetic diseases. It is also used in the development of genetically modified organisms (GMOs) for agricultural and industrial 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.

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.

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.

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.

An Intracisternal A-Particle (IAP) is a type of transposable element in the genome of mice and other rodents. Transposable elements are mobile pieces of DNA that can move or "jump" from one location in the genome to another. IAPs were first discovered in the 1970s and are named for their location within the cisterna of the endoplasmic reticulum in the cell.

IAPs are typically several hundred to a few thousand base pairs in length and contain two main regions: a long terminal repeat (LTR) region at each end, which contains regulatory elements that control the transposition of the IAP, and an internal region that contains genes encoding proteins involved in the transposition process.

IAPs are thought to play a role in genome evolution and have been implicated in various genetic disorders in mice. They can also affect the expression of nearby genes by providing promoter or enhancer elements, or by interfering with normal gene function through insertion into or near a gene.

It's important to note that while IAPs are present in the genomes of many organisms, including humans, they are not typically referred to as "genes" in the traditional sense, as they do not encode functional proteins or RNA molecules that have a direct role in the organism's phenotype.

Artificial bacterial chromosomes (ABCs) are synthetic replicons that are designed to function like natural bacterial chromosomes. They are created through the use of molecular biology techniques, such as recombination and cloning, to construct large DNA molecules that can stably replicate and segregate within a host bacterium.

ABCs are typically much larger than traditional plasmids, which are smaller circular DNA molecules that can also replicate in bacteria but have a limited capacity for carrying genetic information. ABCs can accommodate large DNA inserts, making them useful tools for cloning and studying large genes, gene clusters, or even entire genomes of other organisms.

There are several types of ABCs, including bacterial artificial chromosomes (BACs), P1-derived artificial chromosomes (PACs), and yeast artificial chromosomes (YACs). BACs are the most commonly used type of ABC and can accommodate inserts up to 300 kilobases (kb) in size. They have been widely used in genome sequencing projects, functional genomics studies, and protein production.

Overall, artificial bacterial chromosomes provide a powerful tool for manipulating and studying large DNA molecules in a controlled and stable manner within bacterial hosts.

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.

Prokaryotic cells are simple, single-celled organisms that do not have a true nucleus or other membrane-bound organelles. They include bacteria and archaea. The genetic material of prokaryotic cells is composed of a single circular chromosome located in the cytoplasm, along with small, circular pieces of DNA called plasmids. Prokaryotic cells have a rigid cell wall, which provides protection and support, and a flexible outer membrane that helps them to survive in diverse environments. They reproduce asexually by binary fission, where the cell divides into two identical daughter cells. Compared to eukaryotic cells, prokaryotic cells are generally smaller and have a simpler structure.

A centromere is a specialized region found on chromosomes that plays a crucial role in the separation of replicated chromosomes during cell division. It is the point where the sister chromatids (the two copies of a chromosome formed during DNA replication) are joined together. The centromere contains highly repeated DNA sequences and proteins that form a complex structure known as the kinetochore, which serves as an attachment site for microtubules of the mitotic spindle during cell division.

During mitosis or meiosis, the kinetochore facilitates the movement of chromosomes by interacting with the microtubules, allowing for the accurate distribution of genetic material to the daughter cells. Centromeres can vary in their position and structure among different species, ranging from being located near the middle of the chromosome (metacentric) to being positioned closer to one end (acrocentric). The precise location and characteristics of centromeres are essential for proper chromosome segregation and maintenance of genomic stability.

A "gene" is a basic unit of heredity in living organisms. It is a segment of DNA (deoxyribonucleic acid) that contains the instructions for the development and function of an organism. Genes are responsible for inherited traits, such as eye color, hair color, and height, as well as susceptibility to certain diseases.

"Pol" is short for "polymerase," which is an enzyme that helps synthesize DNA or RNA (ribonucleic acid). In the context of genes, "pol" often refers to "DNA polymerase," an enzyme that plays a crucial role in DNA replication and repair.

Therefore, "genes, pol" may refer to the genes involved in the regulation or function of DNA polymerases. These genes are essential for maintaining the integrity and stability of an organism's genome. Mutations in these genes can lead to various genetic disorders and cancer.

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.

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.

In a medical or scientific context, "Primates" is a biological order that includes various species of mammals, such as humans, apes, monkeys, and prosimians (like lemurs and lorises). This group is characterized by several distinct features, including:

1. A forward-facing eye position, which provides stereoscopic vision and depth perception.
2. Nails instead of claws on most digits, except for the big toe in some species.
3. A rotating shoulder joint that allows for a wide range of motion in the arms.
4. A complex brain with a well-developed cortex, which is associated with higher cognitive functions like problem-solving and learning.
5. Social structures and behaviors, such as living in groups and exhibiting various forms of communication.

Understanding primates is essential for medical and biological research since many human traits, diseases, and behaviors have their origins within this group.

Chromosomes in plants are thread-like structures that contain genetic material, DNA, and proteins. They are present in the nucleus of every cell and are inherited from the parent plants during sexual reproduction. Chromosomes come in pairs, with each pair consisting of one chromosome from each parent.

In plants, like in other organisms, chromosomes play a crucial role in inheritance, development, and reproduction. They carry genetic information that determines various traits and characteristics of the plant, such as its physical appearance, growth patterns, and resistance to diseases.

Plant chromosomes are typically much larger than those found in animals, making them easier to study under a microscope. The number of chromosomes varies among different plant species, ranging from as few as 2 in some ferns to over 1000 in certain varieties of wheat.

During cell division, the chromosomes replicate and then separate into two identical sets, ensuring that each new cell receives a complete set of genetic information. This process is critical for the growth and development of the plant, as well as for the production of viable seeds and offspring.

Reverse transcription is the enzymatic process by which an RNA molecule is copied into a DNA sequence. This process is performed by the reverse transcriptase enzyme, which synthesizes a complementary DNA (cDNA) strand using the RNA as a template. Reverse transcription occurs naturally in retroviruses, such as HIV, where it allows the viral RNA genome to be integrated into the host cell's DNA. This mechanism is also used in molecular biology techniques like cDNA cloning and gene expression analysis.

Retroviridae is a family of viruses that includes HIV (Human Immunodeficiency Virus). Retroviridae proteins refer to the various structural and functional proteins that are encoded by the retroviral genome. These proteins can be categorized into three main groups:

1. Group-specific antigen (Gag) proteins: These proteins make up the viral matrix, capsid, and nucleocapsid. They are involved in the assembly of new virus particles.

2. Polymerase (Pol) proteins: These proteins include the reverse transcriptase, integrase, and protease enzymes. Reverse transcriptase is responsible for converting the viral RNA genome into DNA, which can then be integrated into the host cell's genome by the integrase enzyme. The protease enzyme is involved in processing the polyprotein precursors of Gag and Pol into their mature forms.

3. Envelope (Env) proteins: These proteins are responsible for the attachment and fusion of the virus to the host cell membrane. They are synthesized as a precursor protein, which is then cleaved by a host cell protease to form two distinct proteins - the surface unit (SU) and the transmembrane unit (TM). The SU protein contains the receptor-binding domain, while the TM protein forms the transmembrane anchor.

Retroviral proteins play crucial roles in various stages of the viral life cycle, including entry, reverse transcription, integration, transcription, translation, assembly, and release. Understanding the functions of these proteins is essential for developing effective antiretroviral therapies and vaccines against retroviral infections.

Satellite DNA is a type of DNA sequence that is repeated in a tandem arrangement in the genome. These repeats are usually relatively short, ranging from 2 to 10 base pairs, and are often present in thousands to millions of copies arranged in head-to-tail fashion. Satellite DNA can be found in centromeric and pericentromeric regions of chromosomes, as well as at telomeres and other heterochromatic regions of the genome.

Due to their repetitive nature, satellite DNAs are often excluded from the main part of the genome during DNA sequencing projects, and therefore have been referred to as "satellite" DNA. However, recent studies suggest that satellite DNA may play important roles in chromosome structure, function, and evolution.

It's worth noting that not all repetitive DNA sequences are considered satellite DNA. For example, microsatellites and minisatellites are also repetitive DNA sequences, but they have different repeat lengths and arrangements than satellite DNA.

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.

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.

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.

'Zea mays' is the biological name for corn or maize, which is not typically considered a medical term. However, corn or maize can have medical relevance in certain contexts. For example, cornstarch is sometimes used as a diluent for medications and is also a component of some skin products. Corn oil may be found in topical ointments and creams. In addition, some people may have allergic reactions to corn or corn-derived products. But generally speaking, 'Zea mays' itself does not have a specific medical definition.

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.

A provirus is a form of the genetic material of a retrovirus that is integrated into the DNA of the host cell it has infected. Once integrated, the provirus is replicated along with the host's own DNA every time the cell divides, and it becomes a permanent part of the host's genome.

The process of integration involves the reverse transcription of the retroviral RNA genome into DNA by the enzyme reverse transcriptase, followed by the integration of the resulting double-stranded proviral DNA into the host chromosome by the enzyme integrase.

Proviruses can remain dormant and inactive for long periods of time, or they can become active and produce new viral particles that can infect other cells. In some cases, proviruses can also disrupt the normal functioning of host genes, leading to various diseases such as cancer.

A human genome is the complete set of genetic information contained within the 23 pairs of chromosomes found in the nucleus of most human cells. It includes all of the genes, which are segments of DNA that contain the instructions for making proteins, as well as non-coding regions of DNA that regulate gene expression and provide structural support to the chromosomes.

The human genome contains approximately 3 billion base pairs of DNA and is estimated to contain around 20,000-25,000 protein-coding genes. The sequencing of the human genome was completed in 2003 as part of the Human Genome Project, which has had a profound impact on our understanding of human biology, disease, and evolution.

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.

Heterochromatin is a type of chromatin (the complex of DNA, RNA, and proteins that make up chromosomes) that is characterized by its tightly packed structure and reduced genetic activity. It is often densely stained with certain dyes due to its high concentration of histone proteins and other chromatin-associated proteins. Heterochromatin can be further divided into two subtypes: constitutive heterochromatin, which is consistently highly condensed and transcriptionally inactive throughout the cell cycle, and facultative heterochromatin, which can switch between a condensed, inactive state and a more relaxed, active state depending on the needs of the cell. Heterochromatin plays important roles in maintaining the stability and integrity of the genome by preventing the transcription of repetitive DNA sequences and protecting against the spread of transposable elements.

Gene dosage, in genetic terms, refers to the number of copies of a particular gene present in an organism's genome. Each gene usually has two copies (alleles) in diploid organisms, one inherited from each parent. An increase or decrease in the number of copies of a specific gene can lead to changes in the amount of protein it encodes, which can subsequently affect various biological processes and phenotypic traits.

For example, gene dosage imbalances have been associated with several genetic disorders, such as Down syndrome (trisomy 21), where an individual has three copies of chromosome 21 instead of the typical two copies, leading to developmental delays and intellectual disabilities. Similarly, in certain cases of cancer, gene amplification (an increase in the number of copies of a particular gene) can result in overexpression of oncogenes, contributing to tumor growth and progression.

Mammals are a group of warm-blooded vertebrates constituting the class Mammalia, characterized by the presence of mammary glands (which produce milk to feed their young), hair or fur, three middle ear bones, and a neocortex region in their brain. They are found in a diverse range of habitats and come in various sizes, from tiny shrews to large whales. Examples of mammals include humans, apes, monkeys, dogs, cats, bats, mice, raccoons, seals, dolphins, horses, and elephants.

Gene order, in the context of genetics and genomics, refers to the specific sequence or arrangement of genes along a chromosome. The order of genes on a chromosome is not random, but rather, it is highly conserved across species and is often used as a tool for studying evolutionary relationships between organisms.

The study of gene order has also provided valuable insights into genome organization, function, and regulation. For example, the clustering of genes that are involved in specific pathways or functions can provide information about how those pathways or functions have evolved over time. Similarly, the spatial arrangement of genes relative to each other can influence their expression levels and patterns, which can have important consequences for phenotypic traits.

Overall, gene order is an important aspect of genome biology that continues to be a focus of research in fields such as genomics, genetics, evolutionary biology, and bioinformatics.

DNA methylation is a process by which methyl groups (-CH3) are added to the cytosine ring of DNA molecules, often at the 5' position of cytospine phosphate-deoxyguanosine (CpG) dinucleotides. This modification is catalyzed by DNA methyltransferase enzymes and results in the formation of 5-methylcytosine.

DNA methylation plays a crucial role in the regulation of gene expression, genomic imprinting, X chromosome inactivation, and suppression of transposable elements. Abnormal DNA methylation patterns have been associated with various diseases, including cancer, where tumor suppressor genes are often silenced by promoter methylation.

In summary, DNA methylation is a fundamental epigenetic modification that influences gene expression and genome stability, and its dysregulation has important implications for human health and disease.

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.

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.

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.

A laboratory (often abbreviated as lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurements may be performed. In the medical field, laboratories are specialized spaces for conducting diagnostic tests and analyzing samples of bodily fluids, tissues, or other substances to gain insights into patients' health status.

There are various types of medical laboratories, including:

1. Clinical Laboratories: These labs perform tests on patient specimens to assist in the diagnosis, treatment, and prevention of diseases. They analyze blood, urine, stool, CSF (cerebrospinal fluid), and other samples for chemical components, cell counts, microorganisms, and genetic material.
2. Pathology Laboratories: These labs focus on the study of disease processes, causes, and effects. Histopathology involves examining tissue samples under a microscope to identify abnormalities or signs of diseases, while cytopathology deals with individual cells.
3. Microbiology Laboratories: In these labs, microorganisms like bacteria, viruses, fungi, and parasites are cultured, identified, and studied to help diagnose infections and determine appropriate treatments.
4. Molecular Biology Laboratories: These labs deal with the study of biological molecules, such as DNA, RNA, and proteins, to understand their structure, function, and interactions. They often use techniques like PCR (polymerase chain reaction) and gene sequencing for diagnostic purposes.
5. Immunology Laboratories: These labs specialize in the study of the immune system and its responses to various stimuli, including infectious agents and allergens. They perform tests to diagnose immunological disorders, monitor immune function, and assess vaccine effectiveness.
6. Toxicology Laboratories: These labs analyze biological samples for the presence and concentration of chemicals, drugs, or toxins that may be harmful to human health. They help identify potential causes of poisoning, drug interactions, and substance abuse.
7. Blood Banks: Although not traditionally considered laboratories, blood banks are specialized facilities that collect, test, store, and distribute blood and its components for transfusion purposes.

Medical laboratories play a crucial role in diagnosing diseases, monitoring disease progression, guiding treatment decisions, and assessing patient outcomes. They must adhere to strict quality control measures and regulatory guidelines to ensure accurate and reliable results.

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 telomere is a region of repetitive DNA sequences found at the end of chromosomes, which protects the genetic data from damage and degradation during cell division. Telomeres naturally shorten as cells divide, and when they become too short, the cell can no longer divide and becomes senescent or dies. This natural process is associated with aging and various age-related diseases. The length of telomeres can also be influenced by various genetic and environmental factors, including stress, diet, and lifestyle.

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.

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.

'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.

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.

In situ hybridization, fluorescence (FISH) is a type of molecular cytogenetic technique used to detect and localize the presence or absence of specific DNA sequences on chromosomes through the use of fluorescent probes. This technique allows for the direct visualization of genetic material at a cellular level, making it possible to identify chromosomal abnormalities such as deletions, duplications, translocations, and other rearrangements.

The process involves denaturing the DNA in the sample to separate the double-stranded molecules into single strands, then adding fluorescently labeled probes that are complementary to the target DNA sequence. The probe hybridizes to the complementary sequence in the sample, and the location of the probe is detected by fluorescence microscopy.

FISH has a wide range of applications in both clinical and research settings, including prenatal diagnosis, cancer diagnosis and monitoring, and the study of gene expression and regulation. It is a powerful tool for identifying genetic abnormalities and understanding their role in human disease.

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.

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.

"Drosophila" is a genus of small flies, also known as fruit flies. The most common species used in scientific research is "Drosophila melanogaster," which has been a valuable model organism for many areas of biological and medical research, including genetics, developmental biology, neurobiology, and aging.

The use of Drosophila as a model organism has led to numerous important discoveries in genetics and molecular biology, such as the identification of genes that are associated with human diseases like cancer, Parkinson's disease, and obesity. The short reproductive cycle, large number of offspring, and ease of genetic manipulation make Drosophila a powerful tool for studying complex biological processes.

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.

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.

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.

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.

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.

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.

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.

Diversity-generating retroelements (DGRs) are a family of retroelements that were first found in Bordetella phage (BPP-1), and ... Ye, Yuzhen (2014-08-15). "Identification of Diversity-Generating Retroelements in Human Microbiomes". International Journal of ... "A diversity-generating retroelement encoded by a globally ubiquitous Bacteroides phage". Microbiome. 6 (1): 191. doi:10.1186/ ... "Conservation of the C-type lectin fold for massive sequence variation in a Treponema diversity-generating retroelement". ...
Gogvadze E, Buzdin A (December 2009). "Retroelements and their impact on genome evolution and functioning". Cellular and ... Ishak, Charles A.; De Carvalho, Daniel D. (2020). "Reactivation of Endogenous Retroelements in Cancer Development and Therapy ... Deininger PL, Batzer MA (October 2002). "Mammalian retroelements". Genome Research. 12 (10): 1455-65. doi:10.1101/gr.282402. ...
... s were the first family of retroelement discovered in bacteria; the other two families of known bacterial retroelements ... diversity-generating retroelements (DGRs). The DGRs are not mobile, but function to diversify DNA sequences. For example, DGRs ... Currently, however, RT-encoding elements, i.e. retroelements, have been found in a wide variety of different bacteria: ... Medhekar B, Mille JF (2007). "Diversity-Generating Retroelements". Current Opinion in Microbiology. 10 (4): 388-395. doi: ...
Fukuda K, Shinkai Y (2020). "SETDB1-Mediated silencing of retroelements". Viruses. 12 (6): 596. doi:10.3390/v12060596. PMC ...
Stetson, DB (2012). "Endogenous retroelements and autoimmune disease". Curr Opin Immunol. 24 (6): 692-7. doi:10.1016/j.coi. ... the upregulation of retroelements in TREX1-null cells has recently been disputed. Similarly, another AGS-related gene product ... that TREX1 can metabolise reverse-transcribed HIV-1 DNA and that single-stranded DNA derived from endogenous retroelements ... SAMHD1 also presents strong potency against activity of multiple non-LTR retroelements, which is independent from SAMHD1's ...
Zimmerly, Steven (2005). "Mobile introns and retroelements in bacteria". In Mullany, Peter (ed.). The Dynamic Bacterial Genome ...
Robart, AR; Zimmerly, S (2005). "Group II intron retroelements: function and diversity". Cytogenetic and Genome Research. 110 ( ...
Boeke, J. D.; Stoye, J. P. (1997). "Retrotransposons, Endogenous Retroviruses, and the Evolution of Retroelements". In Coffin, ...
Furthermore, retroelements in general are largely prevalent in rapidly evolving, mammal-specific gene families whose function ... Bannert N, Kurth R (October 2004). "Retroelements and the human genome: new perspectives on an old relation". Proceedings of ... They are distinguished as germline provirus retroelements due to their integration and reverse-transcription into the nuclear ... Thomas JH, Schneider S (November 2011). "Coevolution of retroelements and tandem zinc finger genes". Genome Research. 21 (11): ...
... and the evolution of retroelements. pp. 343-435. PMID 21433351. {{cite book}}: ,work= ignored (help) Boller, Klaus; König, ...
Mu X, Ahmad S, Hur S (2016-01-01). Alt FW (ed.). "Endogenous Retroelements and the Host Innate Immune Sensors". Advances in ...
In January 2019, the development restarted under Retro. Elements of Metroid Prime have appeared in games such as the Super ...
Mu X, Ahmad S, Hur S (2016). Endogenous Retroelements and the Host Innate Immune Sensors. Advances in Immunology. Vol. 132. pp ...
Chueh AC, Wong LH, Wong N, Choo KH (January 2005). "Variable and hierarchical size distribution of L1-retroelement-enriched ... In Drosophila, Islands of retroelements are major components of the centromeres. In the yeast Schizosaccharomyces pombe (and ... May 2019). "Islands of retroelements are major components of Drosophila centromeres". PLOS Biology. 17 (5): e3000241. doi: ...
Ishak, Charles A.; De Carvalho, Daniel D. (9 March 2020). "Reactivation of Endogenous Retroelements in Cancer Development and ...
"Reactivation of Endogenous Retroelements in Cancer Development and Therapy". Annual Review of Cancer Biology. 4: 159-176. doi: ...
Laten, HM; Majumdar, A; Gaucher, EA (9 June 1998). "SIRE-1, a copia/Ty1-like retroelement from soybean, encodes a retroviral ... Pélissier, T; Tutois, S; Deragon, JM; Tourmente, S; Genestier, S; Picard, G (November 1995). "Athila, a new retroelement from ... and rapid evolution of retroelements in the B73 maize genome". PLOS Genetics. 5 (11): e1000732. doi:10.1371/journal.pgen. ... "Network dynamics of eukaryotic LTR retroelements beyond phylogenetic trees". Biology Direct. 4: 41. doi:10.1186/1745-6150-4-41 ...
Xiong Y, Eickbush TH (October 1990). "Origin and evolution of retroelements based upon their reverse transcriptase sequences". ...
Gao, X; Voytas, D (March 2005). "A eukaryotic gene family related to retroelement integrases". Trends in Genetics. 21 (3): 133- ...
Jan 17, 2012). "DUX4 activates germline genes, retroelements, and immune mediators: implications for facioscapulohumeral ...
"Mechanisms of LTR-Retroelement Transposition: Lessons from Drosophilia melanogaster". Viruses. 9: 1-10. Levy, Camille; et al. ( ... Gong, Z; Han, G (2018). "Insect Retroelements Provide Novel Insights into the Origin of Hepatitis B Viruses". Molecular Biology ... the evolutionary history of many retroelements may be challenging to trace (Benachenhou et al., 2013). Scientists often look to ...
For barley, she used molecular cytogenetic techniques to map retroelements on chromosomes. She has collaborated with and ... conserved but nonautonomous retroelements of barley and related genomes. Genetics 166: 1437-1450. DOI: 10.1534/genetics.166.3. ...
From Retroelements to Research Tools". Cold Spring Harbor Perspectives in Biology. 11 (4): a032375. doi:10.1101/cshperspect. ...
Tomilin NV (April 2008). "Regulation of mammalian gene expression by retroelements and non-coding tandem repeats". BioEssays. ...
Tomilin NV (April 2008). "Regulation of mammalian gene expression by retroelements and non-coding tandem repeats". BioEssays. ...
... conserved but nonautonomous retroelements of barley and related genomes". Genetics. 166 (3): 1437-50. doi:10.1534/genetics. ...
Athila retroelements overrepresented in X but absent in Y while tandem repeats enriched in Y-chromosome. Some chloroplast ... The Y become larger and smaller than X due to insertion of retroelement and deletion of genetic material respectively. The ... S. vulgaris has more retroelements in their sex chromosomes compare to S. latifolia. Microsatellite data shows that there is no ... Athila is new family of retroelements, discovered in Arabidopsis thaliana, present in heterochromatin region only. ...
Lathe, R.; Darlix, J. L. (2020). "Prion protein PrP nucleic acid binding and mobilization implicates retroelements as the ... Darlix and Lathe propose that retroelements constitute the replicative component of the transmissible spongiform ...
Some bars also incorporate general nautical themes or retro elements from the early atomic age. Many early tiki bars were ...
LTR retroelements and integrase-related transposons of the pea aphid Acyrthosiphon pisum genome". Mobile Genetic Elements. 1 (2 ...
Diversity-generating retroelements (DGRs) are a family of retroelements that were first found in Bordetella phage (BPP-1), and ... Ye, Yuzhen (2014-08-15). "Identification of Diversity-Generating Retroelements in Human Microbiomes". International Journal of ... "A diversity-generating retroelement encoded by a globally ubiquitous Bacteroides phage". Microbiome. 6 (1): 191. doi:10.1186/ ... "Conservation of the C-type lectin fold for massive sequence variation in a Treponema diversity-generating retroelement". ...
... the reverse-transcribed cDNA of endogenous retroelements. The interplay between innate im … ... The enemy within: endogenous retroelements and autoimmune disease Nat Immunol. 2014 May;15(5):415-22. doi: 10.1038/ni.2872. ... Finally, we discuss how better understanding of the intersection of retroelement biology and innate immunity can guide the way ... The interplay between innate immune sensing and clearance of retroelement cDNA has important implications for the understanding ...
... and this is evident in the extraordinary abundance of endogenous retroelements in the genome of all … ... Immune responses to endogenous retroelements: taking the bad with the good Nat Rev Immunol. 2016 Apr;16(4):207-19. doi: 10.1038 ... However, although retroelements are mainly recognized for their pathogenic potential, recent evidence suggests that this enemy ... Many of these endogenous retroelements have retained viral characteristics; some also the capacity to replicate and, ...
Repeated sequences constituted 91.6% of the genome, Retroelements constituted 53.5% of the repeated fraction representing 39 ( ...
We transferred two retroelements, human LINE-1 and the bacterial group II intron Ll.LtrB, into bacteria, and find that both are ... Abstract: V66.00006 : Testing the Retroelement Invasion Hypothesis for the Emergence of the Ancestral Eukaryotic Cell*. 4:18 PM ... We show that the only stable evolutionary consequence in simple cells is maintenance of retroelements in low numbers, and that ... We find, surprisingly, that retroelement lethality and proliferation is enhanced by the ability to perform eukaryotic-like ...
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Retroelement Insertion in a CRISPR/Cas9 Editing Site in the Early Embryo Intensifies Genetic Mosaicism. Retrovirus production ... Discovery and characterization of the evolution, variation and functions of diversity-generating retroelements using thousands ... Discovery and characterization of the evolution, variation and functions of diversity-generating retroelements using thousands ... Discovery and characterization of the evolution, variation and functions of diversity-generating retroelements using thousands ...
LTR retroelements in the genome of Daphnia pulex Long terminal repeat (LTR) retroelements represent a successful group of ...
eukaryotic cells is to suppress transcriptional activity of the retroelements. Examples of retroelements are endogenous ... for retroelements that were located in the hypomethylated fraction of the genomic DNA. Over 100 Alu sequences were cloned, ... complex diseases that some of the genomic retroelements become transcribed in the affected tissues. Our goal was to screen DNA ... study of the moiety of retroelements is now warranted, and I will discuss how ...
Deniz, Ö., de la Rica, L., Cheng, K.C.L. et al. SETDB1 prevents TET2-dependent activation of IAP retroelements in naïve ... SETDB1 prevents TET2-dependent activation of IAP retroelements in naïve embryonic stem cells. *Özgen Deniz1, ... DNA methylation and SETDB1/H3K9me3 regulate predominantly distinct sets of genes, retroelements, and chimeric transcripts in ... Endogenous retroviruses (ERVs) are retroelements bearing long terminal repeats (LTRs) and constitute approximately 10% of the ...
Interplay of TRIM28 and DNA methylation in controlling human endogenous retroelements. P. Turelli; N. Castro-Diaz; F. Marzetta ... Loss of transcriptional control over endogenous retroelements during reprogramming to pluripotency. M. Friedli; P. Turelli; A. ... As Time Goes by: KRABs Evolve to KAP Endogenous Retroelements. M. Imbeault; D. Trono ...
... retroelements non-LTR retroelements and LY364947 DNA transposons. Probably the most abundant transposable aspect in may be the ... The retrotransposon DIRS-1 may be the most abundant retroelement in and. The retrotransposon DIRS-1 may be the most abundant ... retroelement in and constitutes the pericentromeric heterochromatin from the six chromosomes in led to the accumulation of DIRS ...
CG dinucleotide periodicities recognized by the Dnmt3a-Dnmt3L complex are distinctive at retroelements and imprinted domains. ... CG dinucleotide periodicities recognized by the Dnmt3a-Dnmt3L complex are distinctive at retroelements and imprinted domains. ... CG dinucleotide periodicities recognized by the Dnmt3a-Dnmt3L complex are distinctive at retroelements and imprinted domains. ... CG dinucleotide periodicities recognized by the Dnmt3a-Dnmt3L complex are distinctive at retroelements and imprinted domains. ...
Song, SU, Gerasimova, T, Kurkulos, M, Boeke, JD & Corces, VG 1994, An env-like protein encoded by a Drosophila retroelement: ... An env-like protein encoded by a Drosophila retroelement: Evidence that gypsy is an infectious retrovirus. Genes and ... An env-like protein encoded by a Drosophila retroelement : Evidence that gypsy is an infectious retrovirus. In: Genes and ... An env-like protein encoded by a Drosophila retroelement: Evidence that gypsy is an infectious retrovirus. / Song, Sun U.; ...
Arkhipova, I. R., Pyatkov, K. I., Meselson, M., & Evgenev, M. B. (2003). "Retroelements containing introns in diverse ... Curcio, M. J., & Belfort, M. (2007). "The beginning of the end: links between ancient retroelements and modern telomerases." ... Gladyshev, E. A., & Arkhipova, I. R. (2007). "Telomere-associated endonuclease-deficient Penelope-like retroelements in diverse ... Evgenev, M. B., & Arkhipova, I. R. (2005). "Penelope-like elements-a new class of retroelements: distribution, function and ...
Background Sequences homologous towards the gypsy retroelement from Drosophila melanogaster are. Background Sequences ... homologous towards the gypsy retroelement from Drosophila melanogaster are distributed among drosophilids widely. such as the ...
90s Hearts Retro Elements GraphicsYouworkforthemE9427I am happy to introduce a fun and retro-modern design elements pack titled ...
Jeffrey F. Miller gave a talk focusing on diversity generating retroelements in bacteria which appear to be a means by which ... "Diversity-Generating Retroelements". Steven A. Benner. Foundation for Applied Molecular Evolution, Gainesville, FL. "Molecular ...
Genomic retroelements as candidate drivers of innate immune activation in systemic autoimmune disease. Recognizing the ... Current interests include the role of endogenous RNA, including genomic retroelements, in IFN pathway activation in systemic ... particularly those derived from genomic retroelements, might represent drivers of innate immune system activation in autoimmune ...
Bannert, N. & Kurth, R. Retroelements and the human genome: new perspectives on an old relation. Proc. Natl Acad. Sci. USA 101 ...
Widespread and tissue-specific expression of endogenous retroelements in human somatic tissues. Genome Med. 2020, 12, 40. [ ... Retrotransposon expression and incorporation of cloned human and mouse retroelements in human spermatozoa. Fertil. Steril. 2017 ...
DUX4 activates germline genes, retroelements, and immune mediators: implications for facioscapulohumeral dystrophy. Dev Cell. ...
Contemporary and retro elements combine.. result; vocal pop groove track with soul and strut. Give this crystalline track a ... Contemporary and retro elements combine.. result; a 60 second instrumental pop edm track with soul and strut. Give this ...
Animals, Humans, Retroelements/genetics, Transcriptome, Long Interspersed Nucleotide Elements/genetics, Neurons, Primates/ ... Retroelements/genetics; Transcriptome; Long Interspersed Nucleotide Elements/genetics; Neurons; Primates/genetics}}, language ...
MBD4 loss results in global reactivation of promoters and retroelements with low methylated CpG density. * Christophe Papin ...
Xiong, Y. and Eickbush, T.H. (1990). Origin and evolution of retroelements based upon their reverse transcriptase sequences. ...
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Retro elements abound within Tombolos many garments, one being this "Disco Fungi" cabana shirt. Made from 100% cotton terry, ...
Eco-evolutionary significance of domesticated retroelements in microbial genomes. Mob DNA. 2022 Feb 23;13(1):6. doi: 10.1186/ ...
  • We discuss here an unexpected source of endogenous immunostimulatory nucleic acids: the reverse-transcribed cDNA of endogenous retroelements. (nih.gov)
  • Furthermore, the detection of cDNA by the innate immune system reveals an evolutionary tradeoff: selection for a vigorous, sensitive response to infectious retroviruses may predispose the inappropriate detection of endogenous retroelements. (nih.gov)
  • Retroviruses have invaded the host germ line on the grandest scale, and this is evident in the extraordinary abundance of endogenous retroelements in the genome of all vertebrate species that have been studied. (nih.gov)
  • In this Review, we discuss how the immune system recognizes and is shaped by endogenous retroelements. (nih.gov)
  • The Immunological Conundrum of Endogenous Retroelements. (bvsalud.org)
  • Current interests include the role of endogenous RNA, including genomic retroelements, in IFN pathway activation in systemic autoimmune diseases, along with the role of Toll-like receptor (TLR)-dependent and TLR-independent pathways in innate immune system activation in those disorders. (hss.edu)
  • The interplay between innate immune sensing and clearance of retroelement cDNA has important implications for the understanding of immune responses to infectious retroviruses such as human immunodeficiency virus (HIV). (nih.gov)
  • Endogenous retroviruses (ERVs) are retroelements bearing long terminal repeats (LTRs) and constitute approximately 10% of the mouse genome [ 1 ]. (biomedcentral.com)
  • Repeated sequences constituted 91.6% of the genome, Retroelements constituted 53.5% of the repeated fraction representing 39 (12 Ty1-copia, 20 Ty3-gypsy, five LINE, and two TRIM) families. (harvard.edu)
  • Phylogenetic evidence suggests that the ancestral eukaryotic cell emerged as a result of invasion and proliferation of retroelements, selfish mobile genetic elements that copy and paste themselves within a host genome. (aps.org)
  • For example, ~50% of the human genome consists of spliceosomal introns and non-LTR retroelements. (ucsd.edu)
  • Finally, we discuss how better understanding of the intersection of retroelement biology and innate immunity can guide the way to novel therapies for specific autoimmune diseases. (nih.gov)
  • Here we test this hypothesis by determining the pressures retroelements exert on simple genomes. (aps.org)
  • Long terminal repeat (LTR) retroelements represent a successful group of transposable elements (TEs) that have played an important role in shaping the structure of many eukaryotic genomes. (biomedcentral.com)
  • Paul BG, Eren AM . Eco-evolutionary significance of domesticated retroelements in microbial genomes . (mbl.edu)
  • RETROSAT5: Gypsy-type LTR retroelement from rice. (girinst.org)
  • Transposable components can be categorized in lengthy terminal do it again (LTR) retroelements non-LTR retroelements and LY364947 DNA transposons. (biomedigs.org)
  • We transferred two retroelements, human LINE-1 and the bacterial group II intron Ll.LtrB, into bacteria, and find that both are functional and detrimental to growth. (aps.org)
  • However, although retroelements are mainly recognized for their pathogenic potential, recent evidence suggests that this 'enemy within' may also have beneficial roles in tuning host immune reactivity. (nih.gov)
  • We have previously shown that TET1 binds to multiple retroelements in ESCs, and that both TET1 and TET2 help to maintain LINE-1 elements in a hypomethylated state [ 29 ]. (biomedcentral.com)
  • We show that the only stable evolutionary consequence in simple cells is maintenance of retroelements in low numbers, and that retrotransposition in eukaryotes must be finely tuned to allow proliferation. (aps.org)
  • Group II introns share many structural and/or biochemical features with spliceosomal introns and non-LTR retroelements. (ucsd.edu)
  • Diversity-generating retroelements (DGRs) are a family of retroelements that were first found in Bordetella phage (BPP-1), and since been found in bacteria (e.g.Treponema denticola and Legionella pneumophila), Archaea, Archaean viruses (e.g. (wikipedia.org)
  • Discovery and characterization of the evolution, variation and functions of diversity-generating retroelements using thousands of genomes and metagenomes. (frontiers-of-retrovirology.com)
  • Diversity-generating retroelements (DGRs) are a novel household of retroelements that generate sequence range of DNA to profit their hosts by introducing variations and accelerating the evolution of goal proteins. (frontiers-of-retrovirology.com)
  • Here, we show that sPD-L1 in human healthy tissues and tumours is produced by exaptation of an intronic LINE-2A (L2A) endogenous retroelement in the CD274 gene, encoding PD-L1, which causes omission of the transmembrane domain and the regulatory sequence in the canonical 3' untranslated region. (crick.ac.uk)
  • Surprisingly, two of these proteins are from the same family of retroelement-derived proteins: PEG10, and RTL8. (colorado.edu)
  • This effect is implemented in several ways: a direct effect of the virus on the promoter regions of retroelement-encoding genes, virus interaction with miRNAs causing silencing of transposons, and an effect of the viral RNA on the products of retroelement transcription. (gold.ac.uk)
  • To determine what features of the host cell are important for the proliferation of this class of retroelements, we screened for mutations in host genes that reduced the transposition activity of Tf1. (tamu.edu)
  • eukaryotic cells is to suppress transcriptional activity of the retroelements. (stanleylab.org)
  • For this reason, our bodies employ methylation as a defence mechanism to suppress the activity of these retroelements. (sciencedaily.com)
  • For example, although long interspersed element-1 (LINE-1 or L1) retroelements are active in many cancers whether somatic L1 insertions lead to cancer cell heterogeneity and/or adaptive phenotypes that confer growth or survival advantages during cancer evolution or response to therapy is not clear. (nih.gov)
  • For example, although L1 retroelements are active in many cancers whether somatic L1 insertions lead to cancer cell heterogeneity and/or adaptive phenotypes that confer growth or survival advantages during cancer evolution or response to therapy is not clear. (nih.gov)
  • In Aim 1 of UG3, we will develop the technology to profile all classes of single- and double-strand mosaic mutations at ultra-high fidelity (substitutions, insertions, deletions, structural variants, and retroelements). (hhs.gov)
  • The retroelement Lx9 puts a brake on the immune response to virus infection. (garvan.org.au)
  • Retroelements play a key role in brain functioning in humans and other animals, since they represent dynamic regulatory elements controlling the expression of specific neuron types. (gold.ac.uk)
  • The activity of retroelements in the brain is impaired under the influence of SARS-CoV-2, penetrating the blood-brain barrier. (gold.ac.uk)
  • The overall goal of this funding opportunity announcement (FOA) is to encourage applications to investigate mechanisms regulating the expression and activity of mobile genetic elements, including long terminal repeat (LTR) and non-LTR retroelements, in cancer. (nih.gov)
  • Nevertheless, in the absence of IN, retroelements can retain significant levels of insertion activity. (nih.gov)
  • We propose a new concept, according to which the neurological complications of COVID-19 and their long-term effects are caused by modified expression of retroelements in neurons due to viral effect. (gold.ac.uk)
  • A new member of the Sin3 family of corepressors is essential for cell viability and required for retroelement propagation in fission yeast. (tamu.edu)