A method of detecting gene mutation by mixing PCR-amplified mutant and wild-type DNA followed by denaturation and reannealing. The resultant products are resolved by gel electrophoresis, with single base substitutions detectable under optimal electrophoretic conditions and gel formulations. Large base pair mismatches may also be analyzed by using electron microscopy to visualize heteroduplex regions.
Double-stranded nucleic acid molecules (DNA-DNA or DNA-RNA) which contain regions of nucleotide mismatches (non-complementary). In vivo, these heteroduplexes can result from mutation or genetic recombination; in vitro, they are formed by nucleic acid hybridization. Electron microscopic analysis of the resulting heteroduplexes facilitates the mapping of regions of base sequence homology of nucleic acids.
Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
Variation in a population's DNA sequence that is detected by determining alterations in the conformation of denatured DNA fragments. Denatured DNA fragments are allowed to renature under conditions that prevent the formation of double-stranded DNA and allow secondary structure to form in single stranded fragments. These fragments are then run through polyacrylamide gels to detect variations in the secondary structure that is manifested as an alteration in migration through the gels.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
A group of replication-defective viruses, in the genus GAMMARETROVIRUS, which are capable of transforming cells, but which replicate and produce tumors only in the presence of Murine leukemia viruses (LEUKEMIA VIRUS, MURINE).
A temperate inducible phage and type species of the genus lambda-like viruses, in the family SIPHOVIRIDAE. Its natural host is E. coli K12. Its VIRION contains linear double-stranded DNA with single-stranded 12-base 5' sticky ends. The DNA circularizes on infection.
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.
A plasmid whose presence in the cell, either extrachromosomal or integrated into the BACTERIAL CHROMOSOME, determines the "sex" of the bacterium, host chromosome mobilization, transfer via conjugation (CONJUGATION, GENETIC) of genetic material, and the formation of SEX PILI.
A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)
Biochemical identification of mutational changes in a nucleotide sequence.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
Biologically active DNA which has been formed by the in vitro joining of segments of DNA from different sources. It includes the recombination joint or edge of a heteroduplex region where two recombining DNA molecules are connected.
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.
Deoxyribonucleic acid that makes up the genetic material of viruses.
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.
A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.
The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
The functional hereditary units of VIRUSES.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation.
A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) arising during the propagation of S37 mouse sarcoma, and causing lymphoid leukemia in mice. It also infects rats and newborn hamsters. It is apparently transmitted to embryos in utero and to newborns through mother's milk.
A methyl-directed mismatch DNA REPAIR protein that has weak ATPASE activity. MutS was originally described in ESCHERICHIA COLI.
The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.
A large, nuclear protein, encoded by the BRCA2 gene (GENE, BRCA2). Mutations in this gene predispose humans to breast and ovarian cancer. The BRCA2 protein is an essential component of DNA repair pathways, suppressing the formation of gross chromosomal rearrangements. (from Genes Dev. 2000;14(11):1400-6)
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.
The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.
A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.
Any method used for determining the location of and relative distances between genes on a chromosome.
Detection of a MUTATION; GENOTYPE; KARYOTYPE; or specific ALLELES associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing.
Any detectable and heritable alteration in the lineage of germ cells. Mutations in these cells (i.e., "generative" cells ancestral to the gametes) are transmitted to progeny while those in somatic cells are not.
The presence of an uncomplimentary base in double-stranded DNA caused by spontaneous deamination of cytosine or adenine, mismatching during homologous recombination, or errors in DNA replication. Multiple, sequential base pair mismatches lead to formation of heteroduplex DNA; (NUCLEIC ACID HETERODUPLEXES).
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
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 asymmetrical segregation of genes during replication which leads to the production of non-reciprocal recombinant strands and the apparent conversion of one allele into another. Thus, e.g., the meiotic products of an Aa individual may be AAAa or aaaA instead of AAaa, i.e., the A allele has been converted into the a allele or vice versa.
A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.
The reciprocal exchange of segments at corresponding positions along pairs of homologous CHROMOSOMES by symmetrical breakage and crosswise rejoining forming cross-over sites (HOLLIDAY JUNCTIONS) that are resolved during CHROMOSOME SEGREGATION. Crossing-over typically occurs during MEIOSIS but it may also occur in the absence of meiosis, for example, with bacterial chromosomes, organelle chromosomes, or somatic cell nuclear chromosomes.
Disruption of the secondary structure of nucleic acids by heat, extreme pH or chemical treatment. Double strand DNA is "melted" by dissociation of the non-covalent hydrogen bonds and hydrophobic interactions. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible.
A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.
The reformation of all, or part of, the native conformation of a nucleic acid molecule after the molecule has undergone denaturation.

Molecular genetic study of autosomal dominant retinitis pigmentosa in Lithuanian patients. (1/207)

Lithuanian patients with visual problems were clinically examined for retinitis pigmentosa (RP). A total of 33 unrelated families with autosomal dominant RP (adRP) were identified. Screening for mutations in the rhodopsin (RHO) and peripherin/RDS (RDS) genes was performed using DNA heteroduplex analysis. Direct DNA sequencing in the cases of heteroduplex formation showed the presence of the following mutations and polymorphisms in 14 adRP patients: RHO gene - Lys248Arg (1 case), and Pro347Leu (2 cases); RDS gene - Glu304Gln (12 cases), Lys310Arg (5 cases), and Gly338Asp (12 cases). The presence of these mutations (except Lys248Arg in the RHO gene) was confirmed by relevant restriction enzyme digestion. The frequency of the RDS gene mutations Glu304Gln and Gly338Asp was estimated to be 36.4%, while mutation Lys310Arg was less frequent (15.2%). These 3 RDS gene mutations appear to be polypeptide polymorphisms not related to adRP.  (+info)

Human NDUFB9 gene: genomic organization and a possible candidate gene associated with deafness disorder mapped to chromosome 8q13. (2/207)

Human NADH dehydrogenase (ubiquinone) 1beta-subcomplex, 9 (NDUFB9) is a nuclear encoded mitochondrial protein with the respiratory electron transport chain. It has been physically mapped to a 1-Mb deletion at chromosome 8q13 which also contains the gene for branchio-oto-renal (BOR) syndrome. BOR syndrome is characterized by branchial and renal abnormalities with hearing impairment. Since several hereditary deafness disorders have been associated with mitochondrial mutations, NDUFB9 was considered a candidate gene for BOR syndrome. Recently, EYA1 gene has been identified in the region which underlies the BOR syndrome but majority of BOR families did not show mutations in the EYA1 gene. Here we have determined the genomic structure of the NDUFB9 gene, including the nucleotide sequence, organization and the boundaries of the four coding exons. PCR primers were designed from the adjacent intron sequences that allow amplification of the four exons that encode the complete open reading frame. To identify whether mutations in NDUFB9 are involved in causing the BOR syndrome, we screened 9 BOR families which did not show mutations in the EYA1 gene by heteroduplex analysis; however, no mutations were found.  (+info)

Molecular fingerprinting reveals non-overlapping T cell oligoclonality between an inflamed site and peripheral blood. (3/207)

We have demonstrated a stable expansion of CD8+ T cells in the peripheral blood of a child with chronic arthritis. The expanded TCRBV family (TCRBV14) was enriched for CD57hiCD28- T cells. Sequencing of the TCRBV14 amplification products showed a TCR sequence which contributed 32% of the total TCR in the CD8+TCRBV14 population. Using the modified heteroduplex technique, the CD8+TCRBV14 cells showed a clonal pattern and these bands were restricted to the CD28- population. This method also detected multiple other clones within the CD8+ population but few in the CD4+ cells. The dominant TCRBV14+ clone was not detectable in synovial fluid T cells from two inflamed joints by CDR3 length analysis or heteroduplex probing, suggesting that this long-lived clone is excluded from inflammatory sites. Synovial fluid T cells showed an unexpected discordance of the CD28 and CD57 phenotype compared to peripheral blood mononuclear cells. T cells from both inflamed joints both showed marked oligoclonality in all TCR families and had almost identical heteroduplex patterns. Taken together these data suggest that some clones are actively excluded from inflamed sites in juvenile chronic arthritis, yet the pattern of restricted T cell expansion is shared between sites of inflammation.  (+info)

Spectrum of mutations in the HFE gene implicated in haemochromatosis and porphyria. (4/207)

Mutation analysis was performed on DNA samples of 965 individuals from four different ethnic groups in South Africa, in an attempt to determine the spectrum of sequence variants in the haemochromatosis ( HFE ) gene. This population screening approach, utilizing a combined heteroduplex and single-strand conformation polymorphism (HEX-SSCP) method, revealed three previously described and four novel missense mutations. Novel variants V53M and V59M were identified in exon 2, Q127H in exon 3 and R330M in exon 5. The exon 5 variant was identified in one of 13 patients referred for a molecular diagnosis of hereditary haemochromatosis (HH), who tested negative for the known C282Y and H63D mutations. Mutation Q127H was detected in exon 3 of the HFE gene together with mutation H63D in an apparently severely affected patient previously shown to carry the protoporphyrinogen oxidase ( PPOX ) gene mutation R59W, which accounts for dominantly inherited variegate porphyria (VP) in >80% of affected South Africans. The mutant allele frequency of the C282Y mutation was found to be significantly lower in 73 apparently unrelated VP patients with the R59W mutation than in 102 controls drawn from the same population ( P = 0.005). The population screening approach used in this study revealed considerable genotypic variation in the HFE gene and supports previous data on the involvement of this gene in the porphyria phenotype.  (+info)

Optimal temperature selection for mutation detection by denaturing HPLC and comparison to single-stranded conformation polymorphism and heteroduplex analysis. (5/207)

BACKGROUND: Denaturing HPLC (DHPLC) is a semi-automated method for detecting unknown DNA sequence variants. The sensitivity of the method is dependent on the temperature at which the analysis is undertaken, the selection of which is dependent on operator experience. To circumvent this, software has been developed for predicting the optimal temperature for DHPLC analysis. We examined the utility of this software. METHODS: To maximize the relevance of our data for other investigators, we have screened 42 different amplimers from CFTR, TSC1, and TSC2. The samples consisted of 103 unique sequence heterozygotes and 126 wild-type homozygous controls. RESULTS: At the temperature recommended by the software, 96% (99 of 103) of heterozygotes and all of the wild-type controls were correctly classified. This compares favorably with sensitivities of 85% for single-stranded conformation polymorphism and 82% for gel-based heteroduplex analyses of the same fragments. CONCLUSIONS: Software-optimized DHPLC is a highly sensitive method for mutation detection. However, where sensitivity >96% is required, our data suggest that in addition to the recommended temperature, fragments should also be run at the recommended temperature plus 2 degrees C.  (+info)

DNA sequence heterogeneity in the three copies of the long 16S-23S rDNA spacer of Enterococcus faecalis isolates. (6/207)

The possibility of intragenic heterogeneity between copies of the long intergenic (16S-23S rDNA) spacer region (LISR) was investigated by specific amplification of this region from 21 Enterococcus faecalis isolates. Three copies of the LISR (rrnA, B and C) were demonstrated by hybridization of the LISR to genomic DNA cleaved with I-Ceul and SmaI. When the LISR amplicon was digested with Tsp509I, two known nucleotide substitutions were detected, one 4 nt upstream from the 5' end of the tRNA(ala) gene (allele rrnB has the Tsp509I site and rrnA and C do not) and the other 22 nt downstream from the 3' end of the tRNA(ala) gene (rrnC has the Tsp509I site). Sequence differences at these sites were detected at the allelic level (alleles rrnA, B and C) and different combinations of these alleles were designated Tsp Types. Using densitometry to analyse bands from electrophoresis gels, the intra-isolate ratios of the separate alleles (rrnA:rrnB:rrnC) were determined in each Tsp Type: I (0:3:0), II (1:2:0), III (2:0:1), IV (3:0:0), V (2:1:0) and VI (1:1:1). Sequence variation between the three copies of the LISR was confirmed by the detection of at least five other intra-isolate nucleotide substitutions using heteroduplex analysis by conformation-sensitive gel electrophoresis (CSGE) that were not detected by Tsp509I cleavage. Perpendicular denaturing gradient gel electrophoresis was capable of resolving homoduplexes; six to seven out of a possible nine curves were obtained in some isolates. In the isolate where seven curves were obtained one or more further nucleotide substitutions, not detected by Tsp509I cleavage or CSGE, were detected. On the basis of LISR sequence heterogeneity, isolates were categorized into homogeneous (only one allele sequence present) and heterogeneous (two or three allele sequences present). The transition between homogeneous and heterogeneous LISRs may be useful in studying evolutionary mechanisms between E. faecalis isolates.  (+info)

Heteroduplex analysis of VDJ amplified segments from rearranged IgH genes for clonality assessments in B-cell non-Hodgkin's lymphoma. A comparison between different strategies. (7/207)

BACKGROUND AND OBJECTIVE: The main difficulty of PCR-based clonality studies for B-cell lymphoproliferative disorders (B-LPD) is discrimination between monoclonal and polyclonal PCR products, especially when there is a high background of polyclonal B cells in the tumor sample. Actually, PCR-based methods for clonality assessment require additional analysis of the PCR products in order to discern between monoclonal and polyclonal samples. Heteroduplex analysis represents an attractive approach since it is easy to perform and avoids the use of radioactive substrates or expensive equipment. DESIGN AND METHODS: We studied the sensitivity and specificity of heteroduplex PCR analysis for monoclonal detection in samples from 90 B-cell non Hodgkin's lymphoma (B-NHL) patients and in 28 individuals without neoplastic B-cell disorders (negative controls). Furthermore, in 42 B-NHL and in the same 28 negative controls, we compared heteroduplex analysis vs the classical PCR technique. We also compared ethidium bromide (EtBr) vs. silver nitrate (AgNO(3)) staining as well as agarose vs. polyacrylamide gel electrophoresis (PAGE). RESULTS: Using two pair consensus primers sited at VH (FR3 and FR2) and at JH, 91% of B-NHL samples displayed monoclonal products after heteroduplex PCR analysis using PAGE and AgNO(3) staining. Moreover, no polyclonal sample showed a monoclonal PCR product. By contrast, false positive results were obtained when using agarose (5/28) and PAGE without heteroduplex analysis: 2/28 and 8/28 with EtBr and AgNO(3) staining, respectively. In addition, false negative results only appeared with EtBr staining: 13/42 in agarose, 4/42 in PAGE without heteroduplex analysis and 7/42 in PAGE after heteroduplex analysis. INTERPRETATION AND CONCLUSIONS: We conclude that AgNO(3) stained PAGE after heteroduplex analysis is the most suitable strategy for detecting monoclonal rearrangements in B-NHL samples because it does not produce false-positive results and the risk of false-negative results is very low.  (+info)

Molecular basis for methionine synthase reductase deficiency in patients belonging to the cblE complementation group of disorders in folate/cobalamin metabolism. (8/207)

Methionine synthase reductase (MSR) deficiency is an autosomal recessive disorder of folate/cobalamin metabolism leading to hyperhomocysteinemia, hypo- methioninemia and megaloblastic anemia. Deficiency in MSR activity occurs as the result of a defect in the MSR enzyme, which is required for the reductive activation of methionine synthase (MS). MS itself is responsible for the folate/cobalamin-dependent conversion of homo- cysteine to methionine. We have recently cloned the cDNA corresponding to the MSR protein, a novel member of the ferredoxin-NADP(+)reductase (FNR) family of electron transferases. We have used RT-PCR, heteroduplex, single-strand conformation poly- morphism (SSCP) and DNA sequence analyses to reveal 11 mutations in eight patients from seven families belonging to the cblE complementation group of patients of cobalamin metabolism that is defective in the MSR protein. The mutations include splicing defects leading to large insertions or deletions, as well as a number of smaller deletions and point mutations. Apart from an intronic substitution found in two unrelated patients, the mutations appear singular among individuals. Of the eleven, three are nonsense mutations, allowing for the identification of two patients for whom little if any MSR protein should be produced. The remaining eight involve point mutations or in-frame disruptions of the coding sequence and are distributed throughout the coding region, including proposed FMN, FAD and NADPH binding sites. These data demonstrate a unique requirement for MSR in the reductive activation of MS.  (+info)

Heteroduplex analysis is a laboratory technique used in molecular biology to detect genetic variations or mutations between two DNA sequences. It involves denaturing (separating) the double-stranded DNA molecules of two different samples, allowing the single strands to reanneal or hybridize with each other. If there are any sequence differences between the two samples, this will result in the formation of heteroduplexes - mismatched double-stranded regions where the base pairing does not follow the usual A-T and G-C rules.

These heteroduplexes can be detected by various methods such as denaturing gradient gel electrophoresis (DGGE), temperature gradient gel electrophoresis (TGGE), or mismatch cleavage using enzymes like T7 endonuclease I or CEL I. The presence and mobility shift of heteroduplex bands in the analysis can indicate the location and type of genetic variation, making it a valuable tool for mutation screening, genotyping, and DNA fingerprinting.

A nucleic acid heteroduplex is a double-stranded structure formed by the pairing of two complementary single strands of nucleic acids (DNA or RNA) that are derived from different sources. The term "hetero" refers to the fact that the two strands are not identical and come from different parents, genes, or organisms.

Heteroduplexes can form spontaneously during processes like genetic recombination, where DNA repair mechanisms may mistakenly pair complementary regions between two different double-stranded DNA molecules. They can also be generated intentionally in laboratory settings for various purposes, such as analyzing the similarity of DNA sequences or detecting mutations.

Heteroduplexes are often used in molecular biology techniques like polymerase chain reaction (PCR) and DNA sequencing, where they can help identify mismatches, insertions, deletions, or other sequence variations between the two parental strands. These variations can provide valuable information about genetic diversity, evolutionary relationships, and disease-causing mutations.

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

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

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

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.

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

Single-Stranded Conformational Polymorphism (SSCP) is not a medical condition but rather a laboratory technique used in molecular biology and genetics. It refers to the phenomenon where a single-stranded DNA or RNA molecule can adopt different conformations or shapes based on its nucleotide sequence, even if the difference in the sequence is as small as a single base pair change. This property is used in SSCP analysis to detect mutations or variations in DNA or RNA sequences.

In SSCP analysis, the denatured single-stranded DNA or RNA sample is subjected to electrophoresis on a non-denaturing polyacrylamide gel. The different conformations of the single-stranded molecules migrate at different rates in the gel, creating multiple bands that can be visualized by staining or other detection methods. The presence of additional bands or shifts in band patterns can indicate the presence of a sequence variant or mutation.

SSCP analysis is often used as a screening tool for genetic diseases, cancer, and infectious diseases to identify genetic variations associated with these conditions. However, it has largely been replaced by more sensitive and accurate methods such as next-generation sequencing.

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.

Sarcoma viruses, murine, are a group of RNA viruses that primarily affect mice and other rodents. They are classified as type C retroviruses, which means they contain an envelope, have reverse transcriptase enzyme activity, and replicate through a DNA intermediate.

The murine sarcoma viruses (MSVs) are associated with the development of various types of tumors in mice, particularly fibrosarcomas, which are malignant tumors that originate from fibroblasts, the cells that produce collagen and other fibers in connective tissue.

The MSVs are closely related to the murine leukemia viruses (MLVs), and together they form a complex called the murine leukemia virus-related viruses (MLVRVs). The MLVRVs can undergo recombination events, leading to the generation of new viral variants with altered biological properties.

The MSVs are important tools in cancer research because they can transform normal cells into tumor cells in vitro and in vivo. The study of these viruses has contributed significantly to our understanding of the molecular mechanisms underlying cancer development and progression.

Bacteriophage lambda, often simply referred to as phage lambda, is a type of virus that infects the bacterium Escherichia coli (E. coli). It is a double-stranded DNA virus that integrates its genetic material into the bacterial chromosome as a prophage when it infects the host cell. This allows the phage to replicate along with the bacterium until certain conditions trigger the lytic cycle, during which new virions are produced and released by lysing, or breaking open, the host cell.

Phage lambda is widely studied in molecular biology due to its well-characterized life cycle and genetic structure. It has been instrumental in understanding various fundamental biological processes such as gene regulation, DNA recombination, and lysis-lysogeny decision.

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.

I'm not aware of a widely recognized or established medical term called "F factor." It is possible that it could be a term specific to certain medical specialties, research, or publications. In order to provide an accurate and helpful response, I would need more context or information about where you encountered this term.

If you meant to ask about the F-plasmid, which is sometimes referred to as the "F factor" in bacteriology, it is a type of plasmid that can be found in certain strains of bacteria and carries genes related to conjugation (the process by which bacteria transfer genetic material between each other). The F-plasmid can exist as an independent circular DNA molecule or integrate into the chromosome of the host bacterium.

If this is not the term you were looking for, please provide more context so I can give a better answer.

Capillary electrophoresis (CE) is a laboratory technique used to separate and analyze charged particles such as proteins, nucleic acids, and other molecules based on their size and charge. In CE, the sample is introduced into a narrow capillary tube filled with a buffer solution, and an electric field is applied. The charged particles in the sample migrate through the capillary towards the electrode with the opposite charge, and the different particles become separated as they migrate based on their size and charge.

The separation process in CE is monitored by detecting the changes in the optical properties of the particles as they pass through a detector, typically located at the end of the capillary. The resulting data can be used to identify and quantify the individual components in the sample. Capillary electrophoresis has many applications in research and clinical settings, including the analysis of DNA fragments, protein identification and characterization, and the detection of genetic variations.

DNA Mutational Analysis is a laboratory test used to identify genetic variations or changes (mutations) in the DNA sequence of a gene. This type of analysis can be used to diagnose genetic disorders, predict the risk of developing certain diseases, determine the most effective treatment for cancer, or assess the likelihood of passing on an inherited condition to offspring.

The test involves extracting DNA from a patient's sample (such as blood, saliva, or tissue), amplifying specific regions of interest using polymerase chain reaction (PCR), and then sequencing those regions to determine the precise order of nucleotide bases in the DNA molecule. The resulting sequence is then compared to reference sequences to identify any variations or mutations that may be present.

DNA Mutational Analysis can detect a wide range of genetic changes, including single-nucleotide polymorphisms (SNPs), insertions, deletions, duplications, and rearrangements. The test is often used in conjunction with other diagnostic tests and clinical evaluations to provide a comprehensive assessment of a patient's genetic profile.

It is important to note that not all mutations are pathogenic or associated with disease, and the interpretation of DNA Mutational Analysis results requires careful consideration of the patient's medical history, family history, and other relevant factors.

Genetic recombination is the process by which genetic material is exchanged between two similar or identical molecules of DNA during meiosis, resulting in new combinations of genes on each chromosome. This exchange occurs during crossover, where segments of DNA are swapped between non-sister homologous chromatids, creating genetic diversity among the offspring. It is a crucial mechanism for generating genetic variability and facilitating evolutionary change within populations. Additionally, recombination also plays an essential role in DNA repair processes through mechanisms such as homologous recombinational repair (HRR) and non-homologous end joining (NHEJ).

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

Recombinant DNA is a term used in molecular biology to describe DNA that has been created by combining genetic material from more than one source. This is typically done through the use of laboratory techniques such as molecular cloning, in which fragments of DNA are inserted into vectors (such as plasmids or viruses) and then introduced into a host organism where they can replicate and produce many copies of the recombinant DNA molecule.

Recombinant DNA technology has numerous applications in research, medicine, and industry, including the production of recombinant proteins for use as therapeutics, the creation of genetically modified organisms (GMOs) for agricultural or industrial purposes, and the development of new tools for genetic analysis and manipulation.

It's important to note that while recombinant DNA technology has many potential benefits, it also raises ethical and safety concerns, and its use is subject to regulation and oversight in many countries.

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.

Viral DNA refers to the genetic material present in viruses that consist of DNA as their core component. Deoxyribonucleic acid (DNA) is one of the two types of nucleic acids that are responsible for storing and transmitting genetic information in living organisms. Viruses are infectious agents much smaller than bacteria that can only replicate inside the cells of other organisms, called hosts.

Viral DNA can be double-stranded (dsDNA) or single-stranded (ssDNA), depending on the type of virus. Double-stranded DNA viruses have a genome made up of two complementary strands of DNA, while single-stranded DNA viruses contain only one strand of DNA.

Examples of dsDNA viruses include Adenoviruses, Herpesviruses, and Poxviruses, while ssDNA viruses include Parvoviruses and Circoviruses. Viral DNA plays a crucial role in the replication cycle of the virus, encoding for various proteins necessary for its multiplication and survival within the host cell.

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.

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

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

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

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

Bacterial DNA refers to the genetic material found in bacteria. It is composed of a double-stranded helix containing four nucleotide bases - adenine (A), thymine (T), guanine (G), and cytosine (C) - that are linked together by phosphodiester bonds. The sequence of these bases in the DNA molecule carries the genetic information necessary for the growth, development, and reproduction of bacteria.

Bacterial DNA is circular in most bacterial species, although some have linear chromosomes. In addition to the main chromosome, many bacteria also contain small circular pieces of DNA called plasmids that can carry additional genes and provide resistance to antibiotics or other environmental stressors.

Unlike eukaryotic cells, which have their DNA enclosed within a nucleus, bacterial DNA is present in the cytoplasm of the cell, where it is in direct contact with the cell's metabolic machinery. This allows for rapid gene expression and regulation in response to changing environmental conditions.

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

Viral genes refer to the genetic material present in viruses that contains the information necessary for their replication and the production of viral proteins. In DNA viruses, the genetic material is composed of double-stranded or single-stranded DNA, while in RNA viruses, it is composed of single-stranded or double-stranded RNA.

Viral genes can be classified into three categories: early, late, and structural. Early genes encode proteins involved in the replication of the viral genome, modulation of host cell processes, and regulation of viral gene expression. Late genes encode structural proteins that make up the viral capsid or envelope. Some viruses also have structural genes that are expressed throughout their replication cycle.

Understanding the genetic makeup of viruses is crucial for developing antiviral therapies and vaccines. By targeting specific viral genes, researchers can develop drugs that inhibit viral replication and reduce the severity of viral infections. Additionally, knowledge of viral gene sequences can inform the development of vaccines that stimulate an immune response to specific viral proteins.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

A plasmid is a small, circular, double-stranded DNA molecule that is separate from the chromosomal DNA of a bacterium or other organism. Plasmids are typically not essential for the survival of the organism, but they can confer beneficial traits such as antibiotic resistance or the ability to degrade certain types of pollutants.

Plasmids are capable of replicating independently of the chromosomal DNA and can be transferred between bacteria through a process called conjugation. They often contain genes that provide resistance to antibiotics, heavy metals, and other environmental stressors. Plasmids have also been engineered for use in molecular biology as cloning vectors, allowing scientists to replicate and manipulate specific DNA sequences.

Plasmids are important tools in genetic engineering and biotechnology because they can be easily manipulated and transferred between organisms. They have been used to produce vaccines, diagnostic tests, and genetically modified organisms (GMOs) for various applications, including agriculture, medicine, and industry.

In the context of medical laboratory reporting, "R factors" refer to a set of values that describe the resistance of certain bacteria to different antibiotics. These factors are typically reported as R1, R2, R3, and so on, where each R factor corresponds to a specific antibiotic or class of antibiotics.

An R factor value of "1" indicates susceptibility to the corresponding antibiotic, while an R factor value of "R" (or "R-", depending on the laboratory's reporting practices) indicates resistance. An intermediate category may also be reported as "I" or "I-", indicating that the bacterium is intermediately sensitive to the antibiotic in question.

It's important to note that R factors are just one piece of information used to guide clinical decision-making around antibiotic therapy, and should be interpreted in conjunction with other factors such as the patient's clinical presentation, the severity of their infection, and any relevant guidelines or recommendations from infectious disease specialists.

The Moloney murine leukemia virus (Mo-MLV) is a type of retrovirus, specifically a gammaretrovirus, that is commonly found in mice. It was first discovered and isolated by John Moloney in 1960. Mo-MLV is known to cause various types of cancerous conditions, particularly leukemia, in susceptible mouse strains.

Mo-MLV has a single-stranded RNA genome that is reverse transcribed into double-stranded DNA upon infection of the host cell. This viral DNA then integrates into the host's genome and utilizes the host's cellular machinery to produce new virus particles. The Mo-MLV genome encodes for several viral proteins, including gag (group-specific antigen), pol (polymerase), and env (envelope) proteins, which are essential for the replication cycle of the virus.

Mo-MLV is widely used in laboratory research as a model retrovirus to study various aspects of viral replication, gene therapy, and oncogenesis. It has also been engineered as a vector for gene delivery applications due to its ability to efficiently integrate into the host genome and deliver large DNA sequences. However, it is important to note that Mo-MLV and other retroviruses have the potential to cause insertional mutagenesis, which can lead to unintended genetic alterations and adverse effects in some cases.

The MutS DNA mismatch-binding protein is a key component of the bacterial DNA mismatch repair system, which plays a crucial role in maintaining genomic stability by correcting errors that occur during DNA replication. This protein is responsible for recognizing and binding to mismatched base pairs or small insertion/deletion loops (known as heteroduplexes) that escape the proofreading activity of polymerase enzymes.

Once bound to a mismatch, MutS undergoes a conformational change and recruits other proteins to form a complex that initiates the repair process. The complex uses the intact strand as a template to remove the incorrect segment, followed by resynthesis of the corrected sequence. This enzyme is highly conserved across various species, including humans, where it is involved in similar DNA repair processes and has been implicated in several hereditary cancer syndromes.

"Gene rearrangement" is a process that involves the alteration of the order, orientation, or copy number of genes or gene segments within an organism's genome. This natural mechanism plays a crucial role in generating diversity and specificity in the immune system, particularly in vertebrates.

In the context of the immune system, gene rearrangement occurs during the development of B-cells and T-cells, which are responsible for adaptive immunity. The process involves breaking and rejoining DNA segments that encode antigen recognition sites, resulting in a unique combination of gene segments and creating a vast array of possible antigen receptors.

There are two main types of gene rearrangement:

1. V(D)J recombination: This process occurs in both B-cells and T-cells. It involves the recombination of variable (V), diversity (D), and joining (J) gene segments to form a functional antigen receptor gene. In humans, there are multiple copies of V, D, and J segments for each antigen receptor gene, allowing for a vast number of possible combinations.
2. Class switch recombination: This process occurs only in mature B-cells after antigen exposure. It involves the replacement of the constant (C) region of the immunoglobulin heavy chain gene with another C region, resulting in the production of different isotypes of antibodies (IgG, IgA, or IgE) that have distinct effector functions while maintaining the same antigen specificity.

These processes contribute to the generation of a diverse repertoire of antigen receptors, allowing the immune system to recognize and respond effectively to a wide range of pathogens.

BRCA2 (pronounced "braca two") protein is a tumor suppressor protein that plays a crucial role in repairing damaged DNA in cells. It is encoded by the BRCA2 gene, which is located on chromosome 13. Mutations in the BRCA2 gene have been associated with an increased risk of developing certain types of cancer, particularly breast and ovarian cancer in women, and breast and prostate cancer in men.

The BRCA2 protein interacts with other proteins to repair double-strand breaks in DNA through a process called homologous recombination. When the BRCA2 protein is not functioning properly due to a mutation, damaged DNA may not be repaired correctly, leading to genetic instability and an increased risk of cancer.

It's important to note that not all people with BRCA2 mutations will develop cancer, but their risk is higher than those without the mutation. Genetic testing can identify individuals who have inherited a mutation in the BRCA2 gene and help guide medical management and screening recommendations.

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.

I must clarify that the term "pedigree" is not typically used in medical definitions. Instead, it is often employed in genetics and breeding, where it refers to the recorded ancestry of an individual or a family, tracing the inheritance of specific traits or diseases. In human genetics, a pedigree can help illustrate the pattern of genetic inheritance in families over multiple generations. However, it is not a medical term with a specific clinical definition.

A point mutation is a type of genetic mutation where a single nucleotide base (A, T, C, or G) in DNA is altered, deleted, or substituted with another nucleotide. Point mutations can have various effects on the organism, depending on the location of the mutation and whether it affects the function of any genes. Some point mutations may not have any noticeable effect, while others might lead to changes in the amino acids that make up proteins, potentially causing diseases or altering traits. Point mutations can occur spontaneously due to errors during DNA replication or be inherited from parents.

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.

Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person's chance of developing or passing on a genetic disorder. Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. For example, a physician may recommend genetic testing to help diagnose a genetic condition, confirm the presence of a gene mutation known to increase the risk of developing certain cancers, or determine the chance for a couple to have a child with a genetic disorder.

There are several types of genetic tests, including:

* Diagnostic testing: This type of test is used to identify or confirm a suspected genetic condition in an individual. It may be performed before birth (prenatal testing) or at any time during a person's life.
* Predictive testing: This type of test is used to determine the likelihood that a person will develop a genetic disorder. It is typically offered to individuals who have a family history of a genetic condition but do not show any symptoms themselves.
* Carrier testing: This type of test is used to determine whether a person carries a gene mutation for a genetic disorder. It is often offered to couples who are planning to have children and have a family history of a genetic condition or belong to a population that has an increased risk of certain genetic disorders.
* Preimplantation genetic testing: This type of test is used in conjunction with in vitro fertilization (IVF) to identify genetic changes in embryos before they are implanted in the uterus. It can help couples who have a family history of a genetic disorder or who are at risk of having a child with a genetic condition to conceive a child who is free of the genetic change in question.
* Pharmacogenetic testing: This type of test is used to determine how an individual's genes may affect their response to certain medications. It can help healthcare providers choose the most effective medication and dosage for a patient, reducing the risk of adverse drug reactions.

It is important to note that genetic testing should be performed under the guidance of a qualified healthcare professional who can interpret the results and provide appropriate counseling and support.

A germ-line mutation is a genetic change that occurs in the egg or sperm cells (gametes), and thus can be passed down from parents to their offspring. These mutations are present throughout the entire body of the offspring, as they are incorporated into the DNA of every cell during embryonic development.

Germ-line mutations differ from somatic mutations, which occur in other cells of the body that are not involved in reproduction. While somatic mutations can contribute to the development of cancer and other diseases within an individual, they are not passed down to future generations.

It's important to note that germ-line mutations can have significant implications for medical genetics and inherited diseases. For example, if a parent has a germ-line mutation in a gene associated with a particular disease, their offspring may have an increased risk of developing that disease as well.

A base pair mismatch is a type of mutation that occurs during the replication or repair of DNA, where two incompatible nucleotides pair up instead of the usual complementary bases (adenine-thymine or cytosine-guanine). This can result in the substitution of one base pair for another and may lead to changes in the genetic code, potentially causing errors in protein synthesis and possibly contributing to genetic disorders or diseases, including cancer.

Sensitivity and specificity are statistical measures used to describe the performance of a diagnostic test or screening tool in identifying true positive and true negative results.

* Sensitivity refers to the proportion of people who have a particular condition (true positives) who are correctly identified by the test. It is also known as the "true positive rate" or "recall." A highly sensitive test will identify most or all of the people with the condition, but may also produce more false positives.
* Specificity refers to the proportion of people who do not have a particular condition (true negatives) who are correctly identified by the test. It is also known as the "true negative rate." A highly specific test will identify most or all of the people without the condition, but may also produce more false negatives.

In medical testing, both sensitivity and specificity are important considerations when evaluating a diagnostic test. High sensitivity is desirable for screening tests that aim to identify as many cases of a condition as possible, while high specificity is desirable for confirmatory tests that aim to rule out the condition in people who do not have it.

It's worth noting that sensitivity and specificity are often influenced by factors such as the prevalence of the condition in the population being tested, the threshold used to define a positive result, and the reliability and validity of the test itself. Therefore, it's important to consider these factors when interpreting the results of a diagnostic test.

Genotype, in genetics, refers to the complete heritable genetic makeup of an individual organism, including all of its genes. It is the set of instructions contained in an organism's DNA for the development and function of that organism. The genotype is the basis for an individual's inherited traits, and it can be contrasted with an individual's phenotype, which refers to the observable physical or biochemical characteristics of an organism that result from the expression of its genes in combination with environmental influences.

It is important to note that an individual's genotype is not necessarily identical to their genetic sequence. Some genes have multiple forms called alleles, and an individual may inherit different alleles for a given gene from each parent. The combination of alleles that an individual inherits for a particular gene is known as their genotype for that gene.

Understanding an individual's genotype can provide important information about their susceptibility to certain diseases, their response to drugs and other treatments, and their risk of passing on inherited genetic disorders to their offspring.

DNA repair is the process by which cells identify and correct damage to the DNA molecules that encode their genome. DNA can be damaged by a variety of internal and external factors, such as radiation, chemicals, and metabolic byproducts. If left unrepaired, this damage can lead to mutations, which may in turn lead to cancer and other diseases.

There are several different mechanisms for repairing DNA damage, including:

1. Base excision repair (BER): This process repairs damage to a single base in the DNA molecule. An enzyme called a glycosylase removes the damaged base, leaving a gap that is then filled in by other enzymes.
2. Nucleotide excision repair (NER): This process repairs more severe damage, such as bulky adducts or crosslinks between the two strands of the DNA molecule. An enzyme cuts out a section of the damaged DNA, and the gap is then filled in by other enzymes.
3. Mismatch repair (MMR): This process repairs errors that occur during DNA replication, such as mismatched bases or small insertions or deletions. Specialized enzymes recognize the error and remove a section of the newly synthesized strand, which is then replaced by new nucleotides.
4. Double-strand break repair (DSBR): This process repairs breaks in both strands of the DNA molecule. There are two main pathways for DSBR: non-homologous end joining (NHEJ) and homologous recombination (HR). NHEJ directly rejoins the broken ends, while HR uses a template from a sister chromatid to repair the break.

Overall, DNA repair is a crucial process that helps maintain genome stability and prevent the development of diseases caused by genetic mutations.

Genetic polymorphism refers to the occurrence of multiple forms (called alleles) of a particular gene within a population. These variations in the DNA sequence do not generally affect the function or survival of the organism, but they can contribute to differences in traits among individuals. Genetic polymorphisms can be caused by single nucleotide changes (SNPs), insertions or deletions of DNA segments, or other types of genetic rearrangements. They are important for understanding genetic diversity and evolution, as well as for identifying genetic factors that may contribute to disease susceptibility in humans.

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.

Gene conversion is a process in genetics that involves the non-reciprocal transfer of genetic information from one region of a chromosome to a corresponding region on its homologous chromosome. This process results in a segment of DNA on one chromosome being replaced with a corresponding segment from the other chromosome, leading to a change in the genetic sequence and potentially the phenotype.

Gene conversion can occur during meiosis, as a result of homologous recombination between two similar or identical sequences. It is a natural process that helps maintain genetic diversity within populations and can also play a role in the evolution of genes and genomes. However, gene conversion can also lead to genetic disorders if it occurs in an important gene and results in a deleterious mutation.

Recombination is a natural process that occurs in cells to exchange genetic information between two similar or identical strands of DNA. This process helps to maintain the stability and diversity of the genome. RecA (RecA protein) is a type of recombinase enzyme found in bacteria, including Escherichia coli, that plays a crucial role in this process.

RecA recombinases are proteins that facilitate the exchange of genetic information between two DNA molecules by promoting homologous pairing and strand exchange. Homologous pairing is the alignment of similar or identical sequences of nucleotides on two different DNA molecules, while strand exchange refers to the physical transfer of one strand of DNA from one molecule to another.

RecA recombinases work by forming a nucleoprotein filament on single-stranded DNA (ssDNA) and then searching for complementary sequences on double-stranded DNA (dsDNA). Once a complementary sequence is found, the RecA protein facilitates the invasion of the ssDNA into the dsDNA, leading to strand exchange and the formation of a joint molecule. This joint molecule can then be used as a template for DNA replication or repair.

RecA recombinases have been extensively studied due to their importance in genetic recombination and DNA repair. They also have potential applications in biotechnology, such as in the development of genome engineering tools and methods for detecting and quantifying specific DNA sequences.

Crossing over, genetic is a process that occurs during meiosis, where homologous chromosomes exchange genetic material with each other. It is a crucial mechanism for generating genetic diversity in sexually reproducing organisms.

Here's a more detailed explanation:

During meiosis, homologous chromosomes pair up and align closely with each other. At this point, sections of the chromosomes can break off and reattach to the corresponding section on the homologous chromosome. This exchange of genetic material is called crossing over or genetic recombination.

The result of crossing over is that the two resulting chromosomes are no longer identical to each other or to the original chromosomes. Instead, they contain a unique combination of genetic material from both parents. Crossing over can lead to new combinations of alleles (different forms of the same gene) and can increase genetic diversity in the population.

Crossing over is a random process, so the location and frequency of crossover events vary between individuals and between chromosomes. The number and position of crossovers can affect the likelihood that certain genes will be inherited together or separated, which is an important consideration in genetic mapping and breeding studies.

Nucleic acid denaturation is the process of separating the two strands of a double-stranded DNA molecule, or unwinding the helical structure of an RNA molecule, by disrupting the hydrogen bonds that hold the strands together. This process is typically caused by exposure to high temperatures, changes in pH, or the presence of chemicals called denaturants.

Denaturation can also cause changes in the shape and function of nucleic acids. For example, it can disrupt the secondary and tertiary structures of RNA molecules, which can affect their ability to bind to other molecules and carry out their functions within the cell.

In molecular biology, nucleic acid denaturation is often used as a tool for studying the structure and function of nucleic acids. For example, it can be used to separate the two strands of a DNA molecule for sequencing or amplification, or to study the interactions between nucleic acids and other molecules.

It's important to note that denaturation is a reversible process, and under the right conditions, the double-stranded structure of DNA can be restored through a process called renaturation or annealing.

Single-stranded DNA (ssDNA) is a form of DNA that consists of a single polynucleotide chain. In contrast, double-stranded DNA (dsDNA) consists of two complementary polynucleotide chains that are held together by hydrogen bonds.

In the double-helix structure of dsDNA, each nucleotide base on one strand pairs with a specific base on the other strand through hydrogen bonding: adenine (A) with thymine (T), and guanine (G) with cytosine (C). This base pairing provides stability to the double-stranded structure.

Single-stranded DNA, on the other hand, lacks this complementary base pairing and is therefore less stable than dsDNA. However, ssDNA can still form secondary structures through intrastrand base pairing, such as hairpin loops or cruciform structures.

Single-stranded DNA is found in various biological contexts, including viral genomes, transcription bubbles during gene expression, and in certain types of genetic recombination. It also plays a critical role in some laboratory techniques, such as polymerase chain reaction (PCR) and DNA sequencing.

Nucleic acid renaturation, also known as nucleic acid reassociation or hybridization, is the process of rejoining two complementary single-stranded nucleic acids (DNA or RNA) to form a double-stranded structure. This process occurs naturally in cells during transcription and DNA replication, but it can also be performed in vitro as a laboratory technique.

Renaturation typically involves denaturing the double-stranded nucleic acids into single strands by heat or chemical methods, followed by controlled cooling or modification of conditions to allow the complementary strands to find each other and reanneal. The rate and specificity of renaturation can be used to study the relatedness and concentration of nucleic acid sequences in a sample.

In molecular biology research, nucleic acid renaturation is often used in techniques such as Southern blotting, Northern blotting, and polymerase chain reaction (PCR) to detect and analyze specific DNA or RNA sequences.

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In addition, when performing high resolution melting analyses, one factor that affects the sensitivity of heteroduplex ... Multi factorial analysis has suggested that the contribution of mechanical noise is the most important factor, and that systems ... Gundry, C.; Vandersteen, J.; Reed, G.; Pryor, R.; Chen, J.; Wittwer, C. (2003). "Amplicon melting analysis with labeled primers ... "Thermal analysis of the vortex tube based thermocycler for fast DNA amplification: Experimental and two-dimensional numerical ...
"Temperature-mediated heteroduplex analysis for the detection of drug-resistant gene mutations in clinical isolates of ... It can detect a ratio of 1:32 heteroduplex to homoduplex for smaller PCR products (~0.6 kb), and 1:16 heteroduplex to ... Mitochondrial DNA analysis might be susceptible to contamination by nuclear mitochondrial DNA sequences co-amplified during the ... The detection of cleaved products indicates the presence of a heteroduplex formed by a mismatch. The location of the mutation/ ...
... usually for biochemistry-based phylogenetic analyses. Another is the heteroduplexes formed when non-natural analogs of nucleic ... Heteroduplex DNA is also a source of small RNAs (smRNAs), causing post-transcriptional gene silencing. Andersen SL, Sekelsky J ... A heteroduplex is a double-stranded (duplex) molecule of nucleic acid originated through the genetic recombination of single ... When mismatches occur in heteroduplex DNA, the sequence of one strand can be repaired to bind the other strand with perfect ...
... heteroduplex analysis, and short tandem repeat (STR) analysis. Resolving DNA fragments according to differences in size and/or ... We have developed a method for the partial automation of DNA sequence analysis. Fluorescence detection of the DNA fragments is ... Dye-primer sequencing facilitates reading in an optical system for faster and more economical analysis and automation. The ... 1986). "Fluorescence detection in automated DNA sequence analysis". Nature. 321 (6071): 674-679. Bibcode:1986Natur.321..674S. ...
... heteroduplex analysis (HDA) by multi-capillary electrophoresis or also dedicated oligonucleotides array based on comparative ... "Mutational analysis of BRCA1 and BRCA2 and clinicopathologic analysis of ovarian cancer in 82 ovarian cancer families: two ... Claes K, Machackova E, De Vos M, Poppe B, De Paepe A, Messiaen L (1999). "Mutation analysis of the BRCA1 and BRCA2 genes in the ... Analysis of mutations that occur with high frequency also permits the study of their clinical expression. Examples of ...
... heteroduplex analysis), mouse genotyping (for cross progeny and genetic linkage analysis), and methylation analysis (for ... The Statistical Analysis group provides project consultation and power analysis, statistical analysis (genetic, microarray, and ... A key component of this facility is the use of high-performance computing and bioinformatics support for NGS analysis. The ... The Genetic Analysis area includes capillary-based genotyping (Applied Biosystems TaqMan and SNaPshot, microsatellites), custom ...
This is due to base-pair mismatching generated as a result of destabilised heteroduplex annealing between wild-type and variant ... HRM analysis is performed on double stranded DNA samples. Typically the user will use polymerase chain reaction (PCR) prior to ... At the beginning of the HRM analysis there is a high level of fluorescence in the sample because of the billions of copies of ... After the PCR process the HRM analysis begins. The process is simply a precise warming of the amplicon DNA from around 50 ˚C up ...
... heteroduplex analysis MeSH E05.393.661.475 - in situ hybridization MeSH E05.393.661.475.350 - in situ hybridization, ... actuarial analysis MeSH E05.318.740.150 - analysis of variance MeSH E05.318.740.150.500 - multivariate analysis MeSH E05.318. ... sequence analysis, dna MeSH E05.393.760.700.300 - dna mutational analysis MeSH E05.393.760.705 - sequence analysis, protein ... discriminant analysis MeSH E05.318.740.400 - factor analysis, statistical MeSH E05.318.740.475 - matched-pair analysis MeSH ...
The mismatched heteroduplexes will have a different melting temperature than the homoduplexes and will not be retained in the ... 2012). "Melt analysis of mismatch amplification mutation assays (Melt-MAMA): a functional study of a cost-effective SNP ... High Resolution Melting analysis is the simplest PCR-based method to understand. Basically, the same thermodynamic properties ... If the target DNA contains a different SNP allele than the normal DNA fragment, heteroduplexes of the target DNA and normal DNA ...
These "mismatches" in the heteroduplex are the basis for the polymorphism detection by DHPLC. Heteroduplexes are thermally less ... In practice, the analysis begins with a standard PCR in order to amplify the fragment of interest. If the amplified region that ... Heteroduplexes are actually double strands of DNA containing a strand from the wild-type allele and a sprig from the ... Therefore, when heteroduplexes are partially denaturated by heating, the negative charges undergo partial relocation and the ...
The TILLING method relies on the formation of DNA heteroduplexes that are formed when multiple alleles are amplified by PCR and ... usually for population genetics analysis. DEcoTILLING is a modification of TILLING and EcoTILLING which uses an inexpensive ...
1989). "Analysis of any point mutation in DNA. The amplification refractory mutation system (ARMS)". Nucleic Acids Res. 17 (7 ... "Single-stranded heteroduplex intermediates in lambda Red homologous recombination". BMC Molecular Biology. 11: 54. doi:10.1186/ ...
2002). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci ... 2007). "The positional influence of the helical geometry of the heteroduplex substrate on human RNase H1 catalysis". Mol. ... 2004). "Structural requirements at the catalytic site of the heteroduplex substrate for human RNase H1 catalysis". J. Biol. ... 2007). "Human RNase H1 discriminates between subtle variations in the structure of the heteroduplex substrate". Mol. Pharmacol ...
Chemical analysis in the 1980s showed that the junction actually preferred the antiparallel conformation, a finding that was ... This causes the Holliday junction to migrate, creating the heteroduplex segments. Depending on which strand was used as a ... Sonntag Brown M, Lim E, Chen C, Nishant KT, Alani E (2013). "Genetic analysis of mlh3 mutations reveals interactions between ... Much of the early analysis of Holliday junction structure was inferred from gel electrophoresis, FRET, and hydroxyl radical and ...
Joshi, Amita; Rao, Basuthkar J (2002). "ATP Hydrolysis Induces Expansion of MutS Contacts on Heteroduplex: A Case for MutS ... Computational Biology: Computational Genomics of organellar genomes; Computational analyses of protein active site geometry, ...
Chouhy D, Bolatti EM, Pérez GR, Giri AA (November 2013). "Analysis of the genetic diversity and phylogenetic relationships of ... "Sequence homologies between bovine papillomavirus genomes mapped by a novel low-stringency heteroduplex method". Virology. 143 ... Selinka HC, Giroglou T, Sapp M (August 2002). "Analysis of the infectious entry pathway of human papillomavirus type 33 ... recombination and phylodynamic analyses. BMC Genomics 20(1):368 Rayment I, Baker TS, Caspar DL, Murakami WT (January 1982). " ...
... a systematic review with meta-analysis and trial sequential analysis". Intensive Care Medicine. 42 (4): 505-520. doi:10.1007/ ... identified by DNA heteroduplex detection". Genomics. 16 (1): 298-299. doi:10.1006/geno.1993.1184. PMID 8486379. Olds RJ, Lane ... Subsequent functional analysis of a group of 1b cases found them not only to have reduced heparin affinity but multiple or ' ... In support of this, analysis of the positioning of P15 Gly in the Figure 5 complex (labelled in model B) shows it to be ...
Levin, Joshua D; Demple, Bruce (1990). "Analysis of class II (hydrolytic) and class I (beta-lyase) apurinic/apyrimidinic ... terminus or a single nucleotide gap containing heteroduplex DNA. The APE2 3'-phosphodiesterase activity can remove modified 3'- ... A Visualization System for Exploratory Research and Analysis" (PDF). J. Comput. Chem. 25 (13): 1605-1612. doi:10.1002/jcc.20084 ...
This heteroduplex enzyme is composed of a heavy chain and a light chain, which are derived from a single precursor protein, and ... a comparative analysis in rat, mouse, pig and human species". Comparative Biochemistry and Physiology. Part B, Biochemistry & ...
... cancer Hereditary mutation Heredity Heritability Hermaphrodite Heterochromatin Heteroduplex Heteroduplex DNA Heteroduplex ... Ligase Line Linear tetrad Linkage Linkage analysis Linkage equilibrium Linkage group Linkage map Linking number Locus Lod score ... Balbiani ring Barr body Basal body Base Base analogue Base pair Base pairs Base sequence Batesian mimicry Bayesian analysis ... Nonsense codon Nonsense mutation Nonsense suppressor Noonan syndrome Norm of reaction Normal distribution Northern analysis ...
The same equipment can be used for analysis of protein, which was first done by Thomas E. Creighton of the MRC Laboratory of ... are difficult to establish and often do not completely resolve heteroduplexes" (Westburg, 2001). These problems are addressed ... The DNA can be eluted from the silver stain for further analysis through PCR amplification. TGGE and DGGE are broadly useful in ... PCR-Based DGGE and FISH Analysis of Methanogens in Anaerobic Closed Digester Tank Treating Palm Oil Mill Effluent. Meisam ...
Since the heteroduplex DNA is used as template, a larger proportion of minor variant DNA will be amplified and be available for ... These can include the use of amplified DNA for RFLP analysis, MALDI-TOF (matrix-assisted laser-desorption-time-of-flight) ... These heteroduplexes will more readily melt at lower temperatures. Hence they are selectively denatured at the Tc. Primer ... Because the mutant allele DNA forms the minority of DNA in the mixture they will be more likely to form mismatch heteroduplex ...
Based on analysis of the molecular properties of the RecA system, Cox concluded that the data "provide compelling evidence that ... After the synapsis event, in the heteroduplex region a process called branch migration begins. In branch migration an unpaired ... producing a region of heteroduplex DNA that is thousands of base pairs long. Since it is a DNA-dependent ATPase, RecA contains ...

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