dict.md logo
Choose languages of interest
SELECT >>
English
German
Advertisement:
Definition
 
enEnglish
Genome definition: The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
genome definition: complete gene complement of an organism, contained in a set of chromosomes in eukaryotes, or a single chromosome in bacteria; can also mean the DNA or RNA molecule in viruses.
genome definition: The complete genetic material of an organism.
Genome definition: The complete genomic content of an organism, and possibly the full DNA sequence of that organism. It is contained in a set of chromosomes in eukaryotes, a single chromosome in bacteria, or a DNA or RNA molecule in viruses.
Genomic Library definition: A form of GENE LIBRARY containing the complete DNA sequences present in the genome of a given organism. It contrasts with a cDNA library which contains only sequences utilized in protein coding (lacking introns).
Genomic Library definition: A collection of DNA molecules, derived from restriction fragments that have been cloned in vectors, that includes all or part of the genetic material of an organism.
Mutation definition: 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.
mutation definition: Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.
Mutation definition: Permanent, transmissible changes in the genetic material of an organism. Mutations can range from a single base change to the loss of a significant portion of a chromosome. These occur when DNA is not repaired prior to replication. Mutations in germ cells can be inherited. However, in somatic cells, they are not inherited. Somatic mutations can arise via exposure to chemical mutagens or ionizing radiation. These fixed changes in the genetic material can, in some cases, lead to cancer or other diseases.
Genomic Imprinting definition: The variable phenotypic expression of a GENE depending on whether it is of paternal or maternal origin, which is a function of the DNA METHYLATION pattern. Imprinted regions are observed to be more methylated and less transcriptionally active. (Segen, Dictionary of Modern Medicine, 1992)
genomic imprinting definition: inherently programmed modifications of the maternal and paternal genetic contributions to a zygote; leads to differentially expressed parental alleles during development and in adulthood; has been implicated as a cause of human disease.
Genomic Imprinting definition: Parent-specific expression or repression of genes or chromosomes in offspring.
Comparative Genomic Hybridization definition: Comparative genomic hybridization (CGH) is a technique that allows the detection of losses and gains in DNA copy number across the entire genome without prior knowledge of specific chromosomal abnormalities. Comparative genomic hybridization utilizes the hybridization of differentially labeled tumor and reference DNA to generate a map of DNA copy number changes in tumor genomes. Comparative genomic hybridization is an ideal tool for analyzing chromosomal imbalances in archived tumor material and for examining possible correlations between these findings and tumor phenotypes. (from Ried et al. J Mol Med 1997 75:801-14)
comparative genomic hybridization definition: technique which produces a map of DNA sequence copy number as a function of chromosomal location throughout the entire genetic genome, and allows the detection of genetic deletions, duplications, and amplifications.
Comparative Genomic Hybridization definition: A method for analyzing and mapping differences in the copy number of specific genes or other large sequences between two sets of chromosomal DNA. It is used to look for large sequence changes such as deletions, duplications, or amplifications within the genomic DNA of an individual (with a tumor for example) or family members or population or between species.
Genomic Instability definition: A biological process consisting of chromosomal rearrangements and duplications. These phenotypes are often seen in the karyotype of cancer cells, where there is an imbalance between the mechanisms of cell-cycle control and mutation rates within aberrant genes. Ataxia telangiectasia is a disease that is resultant from mutations in the ATM gene, which is a cell cycle checkpoint gene. Nijmegen breakage syndrome is also a disease characterized by chromosomal and genomic instability.
Genomic Instability definition: An increased tendency of the GENOME to acquire MUTATIONS when various processes involved in maintaining and replicating the genome are dysfunctional.
Genomic Islands definition: Distinct units in some bacterial, bacteriophage or plasmid GENOMES that are types of MOBILE GENETIC ELEMENTS. Encoded in them are a variety of fitness conferring genes, such as VIRULENCE FACTORS (in "pathogenicity islands or islets"), ANTIBIOTIC RESISTANCE genes, or genes required for SYMBIOSIS (in "symbiosis islands or islets"). They range in size from 10 - 500 kilobases, and their GC CONTENT and CODON usage differ from the rest of the genome. They typically contain an INTEGRASE gene, although in some cases this gene has been deleted resulting in "anchored genomic islands".
Genomic Segment definition: Genomic segment extracted from a library e.g. BAC or YAC library to be used in the genetic manipulation of the animal model.
Molecular Microarrays, Comparative Genomic definition: Microarrays designed to detect genomic gains or losses or changes in the number of copies of a particular gene associated with a disease. The packet samples on the microarray spots consist of large immobilized pieces of DNA with a known chromosomal location for each spot. DNA-labeled samples from normal and diseased tissues are hybridized to the array; an expression pattern with more bright spots indicates that the number of genes involved in the disease has increased. Expression pattern comparative genomic molecular microarrays can be used to determine the extent and/or follow the progress of particular diseases (e.g., cancer tumors).
Genomic Orientation definition: The orientation of a genomic element on the double stranded molecule.
Genomic Identifier definition: One or more characters and/or numbers that are used to identify, name, or characterize the nature, properties, or contents of genomic sequences, mRNA transcripts, protein products, or other class of entities that occurs throughout the genome.
Genomic Molecule Entity definition: The sequences, mRNA transcripts, protein products, or other genome encoded molecules of the cell.
Genomic Feature Physical Location definition: The physical location on a specified chromosome of a feature or area of interest expressed as a base pair position.
Identified Genomic Data and Samples definition: Identified data and samples are labelled with personal identifiers such as name or identification numbers (e.g., social security or national insurance number). As the samples and associated data are directly traceable back to the subject, it is possible to undertake actions such as sample withdrawal or the return of individual results. The use of identified data and samples allows for clinical monitoring, subject follow-up and the addition of new data. Identified data and samples coding offers privacy protection similar to general healthcare confidentiality in everyday medical practice. Identified data and sample coding are generally not considered appropriate for purposes of clinical trials in drug development. (ICH)
Anonymised Genomic Data and Samples definition: Anonymised data and samples are initially single or double coded but the link between the subjects identifiers and the unique code(s) are subsequently deleted. Once the link has been deleted it is no longer possible to trace the data and samples back to the individual through the coding key(s). Anonymisation is intended to prevent subject re-identification. As anonymised samples and associated data are not traceable back to the subject it is not possible to undertake actions such as sample withdrawal, or the return of individual results. The use of anonymised data and samples does not allow for clinical monitoring, subject follow-up or the addition of new data. The deletion of the coding key(s) linking the data and samples to the subjects identifiers provides additional confidentiality and privacy protection over coded data and samples, as it prevents subject re-identification through the use of the coding key(s) (ICH).
Anonymous Genomic Data and Samples definition: Anonymous data and samples are never labelled with personal identifiers and therefore there is no potential to trace back genomic data and samples to an individual subject. In some instances only limited clinical data is associated with anonymous samples. As anonymous samples and associated data are not traceable back to the subject, it is not possible to undertake actions such as sample withdrawal, or the return of individual results. The use of anonymous data and samples does not allow for clinical monitoring, subject follow-up, or the addition of new data.
Single Coded Genomic Data and Samples definition: Single coded data and samples are labelled with a single code and do not carry any personal identifiers. It is possible to trace the data or samples back to the individual with the use of a single coding key. In general, the clinical investigator is responsible for maintaining the coding key. As the samples and associated data are indirectly traceable back to the subject via the coding key, it is possible to undertake actions such as sample withdrawal, or the return of individual results. The use of single coded data and samples allows for clinical monitoring, subject follow-up, or the addition of new data. Single coding is the current standard used in clinical research and offers additional safeguards to the subject identifiers compared to general healthcare confidentiality and privacy protection in everyday medical practice.
Double Coded Genomic Data and Samples definition: Double coded data and samples are initially labelled with a single code and do not carry any personal identifiers. The data and samples are then relabelled with a second code, which is linked to the first code via a second coding key. It is possible to trace the data or samples back to the individual by the use of both coding keys. In general, the clinical investigator is responsible for maintaining the first coding key and does not have access to the second coding key. As the samples and associated data are indirectly traceable back to the subject via the use of both coding keys, it is possible to undertake actions such as sample withdrawal, or the return of individual results. The use of double coded data and samples allows for clinical monitoring, subject follow-up or the addition of new data. The use of the second code provides additional confidentiality and privacy protection for subjects over that of single coded. Access to both coding keys is needed to link any data or samples back to a subject identifier (ICH).
Genomic Biomarker definition: A measurable DNA or RNA characteristic that is an indicator of normal biologic processes, pathogenic processes, and/or response to therapeutic or other intervention. The definition for a genomic biomarker is not limited to human samples. A genomic biomarker could, for example, reflect: the expression of a gene; the function of a gene; the regulation of a gene. A genomic biomarker can consist of one or more deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) characteristics. The definition for a genomic biomarker does not include the measurement and characterisation of proteins or low molecular weight metabolites. DNA characteristics include, but are not limited to: single nucleotide polymorphisms (SNPs); variability of short sequence repeats; DNA modification, e.g., methylation; insertions; deletions; copy number variation; cytogenetic rearrangements, e.g., translocations, duplications, deletions or inversions. RNA characteristics include, but are not limited to: RNA sequence; RNA expression levels; RNA processing, e.g., splicing and editing; microRNA levels (ICH Draft Consensus Guideline E15).
GISTIC definition: A statistical approach for identifying genomic regions of aberration that are more likely to drive cancer pathogenesis. The method identifies those regions of the genome that are aberrant more often than would be expected by chance, with greater weight given to high-amplitude events (high-level copy-number gains or homozygous deletions) that are less likely to represent random aberrations.
Metagenomics definition: The genomic analysis of assemblages of organisms.
Genomic Structural Variation definition: Contiguous large-scale (1000-400,000 basepairs) differences in the genomic DNA between individuals, due to SEQUENCE DELETION; SEQUENCE INSERTION; or SEQUENCE INVERSION.
Segmental Duplications, Genomic definition: Low-copy (2-50) repetitive DNA elements that are highly homologous and range in size from 1000 to 400,000 base pairs.