• mRNA
  • The expression system is made up of a gene, which is encoded by DNA, and the machinery needed to make mRNA from the DNA and translate that into a protein. (news-medical.net)
  • While transcription of prokaryotic protein-coding genes creates messenger RNA (mRNA) that is ready for translation into protein, transcription of eukaryotic genes leaves a primary transcript of RNA (pre-mRNA), which first has to undergo a series of modifications to become a mature mRNA. (wikipedia.org)
  • For example, in the case of embryonic Drosophila development, the genes nanos and bicoid are asymmetrically expressed in the oocyte because maternal cells deposit messenger RNA (mRNA) for these genes in the poles of the egg before it is laid. (wikipedia.org)
  • Furthermore, since immunohistochemistry visualizes the protein generated by the gene, if the protein product diffuses between cells, or has a particularly short or long half-life relative to the mRNA that is used to translate the protein, this can lead to distorted interpretation of which cells are expressing the mRNA. (wikipedia.org)
  • In situ hybridization is an alternate method in which a "probe," a synthetic nucleic acid with a sequence complementary to the mRNA of the gene, is added to the tissue. (wikipedia.org)
  • Genes contain the instructions for making messenger RNA (mRNA), but at any moment each cell makes mRNA from only a fraction of the genes it carries. (wikipedia.org)
  • Expression profiling experiments often involve measuring the relative amount of mRNA expressed in two or more experimental conditions. (wikipedia.org)
  • Using a reference genome, a researcher can usually determine, with some confidence, the original mRNA (and therefore which gene) the tag was extracted from. (wikipedia.org)
  • The following is a list of stages where gene expression is regulated, the most extensively utilised point is Transcription Initiation: Chromatin domains Transcription Post-transcriptional modification RNA transport Translation mRNA degradation In eukaryotes, the accessibility of large regions of DNA can depend on its chromatin structure, which can be altered as a result of histone modifications directed by DNA methylation, ncRNA, or DNA-binding protein. (wikipedia.org)
  • DNA Microarray - A DNA microarray is a high-throughput technology used to measure expression levels of mRNA transcripts or to detect certain changes in the nucleotide sequence. (wikipedia.org)
  • Down-regulated - describes a gene which has been observed to have lower expression (lower mRNA levels) in one sample compared to another sample (usually a control). (wikipedia.org)
  • In gene expression analysis, expression level refers to the amount of mRNA detected in a sample. (wikipedia.org)
  • Gene knockdown - refers to techniques by which the expression of one or more of an organism's genes is reduced, either through genetic modification (a change in the DNA of one of the organism's chromosomes) or by treatment with a reagent such as a short DNA or RNA oligonucleotide with a sequence complementary to either an mRNA transcript or a gene. (wikipedia.org)
  • In addition, the mRNA sequences do not need to be known a priori, so genes or gene variants which are not known can be discovered. (wikipedia.org)
  • Through this, it was shown that female rats expressed higher levels of Kiss 1 mRNA in the AVPV, however there appeared to be no difference in the Kiss 1 expression in the ARC between male and female rats. (wikipedia.org)
  • The hormone level differences between males and destrous females can be shown by the differences in Kiss 1 mRNA expression between male and female rats during their neonatal period (time period between existing in the maternal uterus and existing completely independently). (wikipedia.org)
  • While almost all cells in an organism contain the entire genome of the organism, only a small subset of those genes is expressed as messenger RNA (mRNA) at any given time, and their relative expression can be evaluated. (wikipedia.org)
  • chromosome
  • An example of a chromosome with two genes, each of size 9, is the string (position zero indicates the start of each gene): 012345678012345678 L+a-baccd**cLabacd where "L" represents the natural logarithm function and "a", "b", "c", and "d" represent the variables and constants used in a problem. (wikipedia.org)
  • proteins
  • While knowledge of the precise proteins a cell makes (proteomics) is more relevant than knowing how much messenger RNA is made from each gene, gene expression profiling provides the most global picture possible in a single experiment. (wikipedia.org)
  • Kisspeptins are a group of proteins that come from precursors that are approximately 145 amino acids in length that get reduced to 54 and then finally about 10, 13, or 14 amino acid carboxyl terminals and are encoded by the Kiss 1 gene and are thought to be involved in the initiation of puberty by stimulating the release of the gonadotropin-releasing hormone (GnRH). (wikipedia.org)
  • The rearrangement and organization of these gene segments during the maturation of B cells produce functional proteins.The entire process of rearrangement and organization of these gene segments is the vital source where our body immune system gets its capabilities to recognize and respond to variety of antigens. (wikipedia.org)
  • genetics
  • paper from David Goldstein's lab, A New Way to Look for Diseases' Genetic Roots: The Icelandic gene-hunting firm deCODE genetics, which emerged last week from bankruptcy, has long led in detecting SNPs associated with common disease. (scienceblogs.com)
  • In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, i.e. observable trait. (wikipedia.org)
  • Do not confuse with the genetics definition of Candidate gene. (wikipedia.org)
  • tumor
  • For example, a normal tissue sample can be compared against a corresponding tumor to determine which genes tend to be more (or less) active. (wikipedia.org)
  • Because of these selective properties, the majority of cells within a tumor will share a common profile of gene expression. (wikipedia.org)
  • Of note, similar gene expression patterns associated with metastatic behaviour of breast cancer tumor cells have also been found in breast cancer of dog, the most common tumor of the female dog. (wikipedia.org)
  • single gene
  • Single Gene Shapes the Toil of Ants' Fighter and Forager Castes: Researchers studying the social behavior of ants have found that a single gene underlies both the aggressive behavior of the ant colony's soldiers and the food gathering behavior of its foraging caste. (scienceblogs.com)
  • Reporter
  • The expression distribution of the reporter gene can be determined by visualizing it. (wikipedia.org)
  • Reporter genes can be visualized in living organisms, but both immunohistochemistry and in situ hybridization must be performed in fixed tissues. (wikipedia.org)
  • genetic
  • Gene expression programming belongs to the family of evolutionary algorithms and is closely related to genetic algorithms and genetic programming. (wikipedia.org)
  • Emergenesis - quality of genetic traits that result from a specific configuration of interacting genes, rather than simply their combination. (wikipedia.org)
  • microarrays
  • DNA microarrays measure the relative activity of previously identified target genes. (wikipedia.org)
  • Current cancer research makes use primarily of DNA microarrays in which an arrayed series of microscopic spots of pre-defined DNA oligonucleotides known as probes are covalently attached to a solid surface such as glass, forming what is known as a gene chip. (wikipedia.org)
  • typically
  • Housekeeping gene - typically a constitutive gene that is transcribed at a relatively constant level across many or all known conditions. (wikipedia.org)
  • transcript
  • With respect to a gene, the two strands may be labeled the "template strand," which serves as a blueprint for the production of an RNA transcript, and the "coding strand," which includes the DNA version of the transcript sequence. (wikipedia.org)
  • nodes
  • A gene co-expression network (GCN) is an undirected graph, where each node corresponds to a gene, and a pair of nodes is connected with an edge if there is a significant co-expression relationship between them. (wikipedia.org)
  • cell
  • In this sense, every cell in the human body is an expression system. (news-medical.net)
  • The virus invades a host cell and uses the cell's machinery as a system to generate viral gene products. (news-medical.net)
  • These configurations help form the expression system of the cell by regulating DNA replication and gene expression. (news-medical.net)
  • Some, on the other hand, are extraordinarily intricate and difficult to predict and model, with expression fluctuating wildly from minute to minute or from cell to cell. (wikipedia.org)
  • since the identity of a cell is specified by the collection of genes actively expressed within that cell, if gene expression was uniform spatially and temporally, there could be at most one kind of cell. (wikipedia.org)
  • Many factors determine whether a gene is on or off, such as the time of day, whether or not the cell is actively dividing, its local environment, and chemical signals from other cells. (wikipedia.org)
  • The unique pattern of gene expression for a given cell or tissue is referred to as its molecular signature. (wikipedia.org)
  • For example, in the lymphoid cell, a partial rearrangement of the heavy-chain gene occurs which is followed by complete rearrangement of heavy-chain gene. (wikipedia.org)
  • The final rearrangement of the light chain gene generates immature B cell and mIgM. (wikipedia.org)
  • Usually, the assortment of these gene segments occurs at B cell maturation. (wikipedia.org)
  • probes
  • The figure above represents the output of a two dimensional cluster, in which similar samples (rows, above) and similar gene probes (columns) were organized so that they would lie close together. (wikipedia.org)
  • This can be a short section of a gene or other DNA element that are used as probes to hybridize a cDNA, cRNA or genomic DNA sample (called target) under high-stringency conditions. (wikipedia.org)
  • neurons
  • Kisspeptins also trigger the release of GnRH/LH from the hypothalamus by[clarification needed] In an experiment conducted by researchers at the University of Washington, the National University of Córdoba, and the University of Maryland, it was discovered that female rats have a greater Kiss 1 gene expression because they have a more Kiss 1 neurons than their male counterparts. (wikipedia.org)
  • represents
  • For example, the mathematical expression: ( a − b ) ( c + d ) {\displaystyle {\sqrt {(a-b)(c+d)}}\,} can also be represented as an expression tree: where "Q" represents the square root function. (wikipedia.org)
  • The resulting matrix, called adjacency matrix, represents the graph of the constructed gene co-expression network. (wikipedia.org)
  • messenger
  • Cap analysis gene expression (CAGE) is a technique used in molecular biology to produce a snapshot of the 5′ end of the messenger RNA population in a biological sample. (wikipedia.org)
  • biology
  • Sophisticated programs of gene expression are widely observed in biology, for example to trigger developmental pathways, respond to environmental stimuli, or adapt to new food sources. (wikipedia.org)
  • similar
  • A popular approach to class discovery involves grouping similar genes or samples together using k-means or hierarchical clustering. (wikipedia.org)
  • Each element in this matrix shows how similar the expression level of two genes change together. (wikipedia.org)
  • level
  • Baseline - a measure of the gene expression level of a gene or genes prior to a perturbation in an experiment, as in a negative control. (wikipedia.org)
  • Random rearrangements and recombinations of the gene segments at DNA level to form one kappa or lambda light chain occurs in an orderly fashion. (wikipedia.org)
  • experiments
  • In developing a drug, one may perform gene expression profiling experiments to help assess the drug's toxicity, perhaps by looking for changing levels in the expression of cytochrome P450 genes, which may be a biomarker of drug metabolism. (wikipedia.org)
  • With no hypothesis, there is nothing to disprove, but expression profiling can help to identify a candidate hypothesis for future experiments. (wikipedia.org)