gene

Y chromosome

... other as mirror images. This phenomenon is called gene conversion. It is the non-reciprocal transfer of g...than 99.97 percent identical. The extensive use of gene conversion appears to play a role in the ability of the Y chromosome to edit out genetic mistakes an...

X chromosome

... profile reveals extensive variability in X-linked gene expression in females . Nature 2005;434:400-4. DOI ....

Virus

... virus infections caused by virus vectors used in gene therapy , so their application to human subjects i... to as a virion . A virion is little more than a gene transporter and components of the envelope and capsid provide the mechanism for injecting the viral ...

Trait

...able unit that may produce a trait is called a gene . A gene is a strand of DNA that is part of a very long and compacted string of DNA called a chromosom...

Thomas Hunt Morgan

...ite eye trait was recessive. Morgan thus named the gene white , starting the tradition of naming genes af...morgan , a unit of recombinant frequency used in gene mapping, was named in his honor. External links http://www.columbia.edu/cu/alumni/Magazine...

Taxonomy

...ch of bioinformatics that employs the method of gene sequencing to construct phylogenetic trees . See also systematics scientific classification ontology cladistics Integrated Taxonomic Information System Important publications in taxonomy Folksonomy Fishes Taxonomy (Shar...

Systems biology

...a patient might beexplained through reference to a gene that they might possess. In systemsbiology, attem... Biomedical cybernetics computer simulation gene regulatory network model signalomics Important publications in systems biology Bibliog...

Stem cell

... developing methods for detecting the presence of gene or chromosome abnormalities in embryos before implantation, increasing knowledge about the development of embryos; increasing knowledge about serious disease, or enabling any such knowledge to be applied in developing treatments for serious...

Splicing (genetics)

...ation prior to translation . In eukaryotes , a gene often contains altering sequences known as exons (expressed codons) and introns (interrupting codons). In contrast to prokaryotes , which do not usually have introns, eukaryotes initially create a primary mRNA transcript called pre-mRNA that ...

Spliceosome

...loser to 30,000 genes. However, almost every human gene is thought to have at least two isoforms . Spliceome The term spliceome has been recently coined to describe the complete set of all possible alternative splices in an organism, in analogy to the genome or proteome . It is defined as a co...

Species

...lity of interbreeding and the actual likelihood of gene flow between populations. For example, it is possi... cannot develop, and given reproductive isolation, gene flow between the populations cannot merge the differences. This is not to say that cross breeding do...

Speciation

... modes that become prominent including horizontal gene transfer by viruses and mutations. A further mechanism is parapatry , where the zones of two species abut but do not overlap. There is only partial separation afforded by geography, so individuals of each species may come in contact or cross the...

Sociobiology

...sociobiology is that temperamental traits within a gene pool and between gene pools exist in an ecological balance. Just as an expansion of a sheep population might encourag...

Signal transduction

...signal transduction include the activation of a gene , the production of metabolic energy and cell l... nucleus and enable the production of a certain gene and, thus, the production of a protein. The typical ligands for nuclear receptors are lipophilic...

RNA virus

...the SARS virus and related RNA viruses contain a gene that mutates very slowly. The gene in question has a complex three-dimensional structure which is hypothesized to provide a chemical fu...

RNA

...thesis is one of the most important ways in which gene expression is regulated. RNA world hypothesis...ibed directly ( splicing in eukaryotes ) from a gene 's DNA (in eukaryotes exported into the cytoplasm ) and is used to encode proteins. RNA genes ...

Blood type

...nts. The ABO blood type is controlled by a single gene with three alleles : i , A , and B . The gene encodes a glycosyltransferase , an enzyme that modifies the carbohydrate content of the red blo...

Reverse genetics

... is an approach to discovering the function of a gene that proceeds oppositely to how such discoveries ...ors typically must deduce the function of a normal gene from the effects that follow from damaging or changing it. Otherwise, the two approaches contrast.By...

Restriction enzyme

...ential " restriction sites " appear in almost any gene or chromosome . Meanwhile, the sequences of some...egment of DNA. So no matter the context in which a gene naturally appears, there is probably a pair of restriction enzymes that can snip it out, and which w...

Red Queen

... of the species or group, not at the level of the gene . By contrast, a Red-Queen-type theory that organ...utility of sexual reproduction at the level of the gene by positing that the role of sex is to preserve genes which are currently disadvantageous, but which...

Punctuated equilibrium

...ions exert a strong homogenizing influence [on the gene pool]. New and favorable mutations are diluted by the sheer bulk of the population through which they must spread....But [in] small, peripherally isolated groups [that] are cut off from their parental stock ... selective pressures are usually intens...

Proteomics

...protein diversity cannot be fully characterized by gene expression analysis alone, making proteomics a useful tool for characterizing cells and tissues of interest. To catalog all human proteins and ascertain their functions and interactions presents a daunting challenge for scientists. An international...

Promoter

..., a promoter is a DNA sequence that enables a gene to be transcribed . The promoter is recognized b...tion upstream of the gene, that is, prior to the gene in the direction of transcription. The sequence at -10 is called the Pribnow box and usually consi...

Prion

...l. Since the original hypothesis was proposed, a gene for the PrP protein has been isolated (the PRNP gene), several mutations that cause the variant shape have been identified and successfully cloned, and studies using genetically altered mice have bolstered the prion hypothesis. In 2004, researcher...

Primer

...dentical, primers. They may be convenient if same gene is to be amplified from different organisms , as the genes themselves are probably similar but not identical. The other use for degenerate primers is when primer design is based on protein sequence . As several different codons can code for one ...

Plasmid

...mmercially available for such uses. Initially, the gene to be replicated is inserted in a plasmid . These ...ies of the plasmid then express (make protein) the gene that confers antibiotic resistance. This is typically a protein which can break down any antibiotics...

Phylogenetic tree

... Fig. 2: Unrooted tree for myosin gene A phylogenetic tree is a tree showing th...enetic trees hide any hybridization and lateral gene transfer (Woese 2002) that may have taken place. For these reasons, the proposed PhyloCode (see E...

Phosphorylation

...osphorylation plays is the p53 tumor suppressor gene , which—when active—stimulates transcription of gene that suppress the cell cycle , even to the extent that it undergoes apoptosis . However, this acti...

Phage

... interactions by integrating multiple genes from a gene bank into phages. Model bacteriophages Follow...M13 phage - Phagemid See also Horizontal gene transfer One-step growth curve...

Polymerase chain reaction

...notyping of specific mutations 4.8 Comparison of gene expression 5 External links History ...ical, primers. They may be convenient if the same gene is to be amplified from different organisms , as the genes themselves are probably similar but not...

Parthenogenesis

...of eggs by a male, introducing new material to the gene pool. Hybridogenesis In hybridogenesis reproduction is not completely asexual but instead hemiclonal , with half the genome passing intact to the next generation while the other half is replaced. In hybridogenetic species, females mate with m...

Operon

...ressor is bound to the operator. See also gene regulatory network Lac operon...

Oncogene

An oncogene is a gene that can cause a cell to develop into a tumor ...es Protooncogene A proto oncogene is a gene that is involved in signal transduction and execution of mitogenic signals, usually through its ...

Natural selection

...chanisms of evolution include genetic drift and gene flow . Mutations create the genetic variation ... mixes the DNA of two parents into an offspring), gene flow and genetic drift are also important mechanisms. Competition (typically among males to impr...

Muller's ratchet

... if one animal has the deleterious mutation in one gene and the advantageous mutation in another, while an...n organisms with sexual reproduction. Horizontal gene transfer in bacteria allows a similar situation. Generally, only obligate endosymbionts, mitochon...

Morphogenesis

...tion of other genes and, in turn, these secondary gene products can regulate the expression of still othe...ryo are significantly augmented by new hunchback gene transcription and translation of the resulting zygotically produced mRNA. During early Drosophila...

Molecular genetics

...ss. Once mutants have been isolated, the mutated gene can be molecularly identified. Reverse geneti...uce the deletion of a particular gene, creating a gene knockout . Alternatives include the random induction of DNA deletions and subsequent selection for d...

Modern evolutionary synthesis

...ation and another as a result of genetic drift , gene flow and natural selection . Speciation occur...associated with Richard Dawkins asserts that the gene is the only true unit of selection . Dawkins further extended the Darwinian idea to include non-bi...

Molecular evolution

... (or deleterious ) mutations are removed from the gene pool by natural selection , while more favorable ...cally, the frequency of an allele (variant of a gene ): Mutation detailed above. Genetic drift describes changes in gene frequency that cannot b...

Molecular biology

...ed by the absence of a normal component (e.g. one gene ). The study of " mutants " – organisms whic...l biology . As of the early 2000s , the study of gene structure and function, molecular genetics , has been amongst the most prominent sub-field of molec...

Microevolution

...ution is the occurrence of small-scale changes in gene frequencies in a population over a few generations...nges may be due to several processes: mutation , gene flow , genetic drift , as well as natural selection . Population genetics is the branch of biol...

Mendelian inheritance

...t impart the same characteristic. Each human has a gene that controls height, but there are variations amo...e genes in accordance with the specific height the gene "codes" for. For each character, an organism inherits two genes, one from each parent. This means...

Meiosis

...es so that each gamete carries a sole allele for a gene locus. In addition, the orientation of the metaphase I/II equatorial lining-up is random, resulting in new allelic recombinationis. Independent assortment forms the basis of Mendel 's second law . Lastly, chiasmata causes genetic breaks and the est...

Marfan syndrome

...minant disorder that has been linked to the FBN1 gene on chromosome 15. FBN1 encodes a protein called fibrillin , which is essential for the formation of elastic fibres found in connective tissue. Marfan's Syndrome is associated with incomplete penetrance, therefore not all persons carrying the mu...

Malaria

...ic effects Carriers of the sickle cell anaemia gene are protected against malaria because of their particular hemoglobin mutation ; this explains why sickle cell anemia is particularly common among people of African origin. There is a theory that another hemoglobin mutation, which causes the genetic ...

Major histocompatibility complex

...y complex ( MHC ) is a large genomic region or gene family found in most vertebrates containing man...ple often use the abbreviation MHC to refer to HLA gene products. To disambiguate the usage, some of the biomedical literature uses Mhc to refer specific...

Lyon hypothesis

... profile reveals extensive variability in X-linked gene expression in females. . Nature 2005;434:400-404. PMID 15772666 . Lyon MF. Gene action in the X chromosome of the mouse (Mus musculus L). Nature 1961;190:372-373. PMID 13764598 ....

Locus

...nary computation , a locus is the position of a gene (or other significant sequence) on a chromosome . A locus can be occupied by any of the alleles of the gene. Diploid or polyploid cells are either homozygous (have the same allele at a locus) or heterozygous (have different allel...

List of gene families

This is a list of gene families or gene complexes , that is sets of genes which occur across a number of different species which often se...

Lipase

...ipase Deficiency is caused by mutations in the gene encoding lipoprotein lipase [2] . Cholesteryl E...olman Disease are both caused by mutations in the gene encoding lysosomal lipase, also referred to as lysosomal acid lipase (LAL or LIPA) or acid cholester...

Lambda phage

...rotein encoded by that gene. The lambda repressor gene system consists of (from left to right on the chromosome): cI gene OR3 OR2 OR1 cro gene The lambda repressor is a dimer also known as the cI protein. It regula...

Kary Mullis

...998 Anthony Liversidge: " Kary Mullis, the great gene machine ", Omni magazine, April 1992, Celia Farber: " Interview Kary Mullis ", Spin July 1994. Focuses on his position regarding HIV and AIDS. Personal website...

Isozyme

...ozymes represent different alleles of the same gene , and isozymes represent different genes whose p...re the product of different alleles of the same gene (described as allozymes ). Isozymes are usually the result of gene duplication , but can also ar...

Ion channel

...shed through electrophysiology , biochemistry , gene sequence comparison and mutagenesis . History The existence of ion channels was hypothesized by the British biophysicists Alan Hodgkin and Andrew Huxley as part of their Nobel Prize -winning theory of the nerve impulse, published in 19...

Intron

Introns are sections of DNA within a gene that do not encode part of the protein that the gene produces, and are spliced out of the mRNA that is transcribed from the gene before it is expor...

Insulin

... level also regulates expression of the insulin gene via the calcium responsive element binding protein ( CREB ). This is the main mechanism for release of insulin and regulation of insulin synthesis. In addition some insulin synthesis and release takes place generally at food intake, not just gluco...

Human Genome Project

...ly planned to patent all genes found, unlike the gene sequences found by the original publicly-funded HG...tions with other genes, body tissues in which this gene is activated, diseases associated with this gene... the list of datatypes is long, one reason why b...

Homozygote

...means that it carries two identical copies of that gene on the two corresponding chromosomes (e.g. the genotype is AA or aa ). A homozygous dominant genotype occurs when a particular locus comprises two alleles for the dominant trait (e.g. AA ).A homozygous recessive genotype occurs when a ...

Human

...e on the X chromosome. Women have a blood-clotting gene on each X chromosome so that one normal blood-clotting gene can compensate for a flaw in the gene on the other X chromosome. But men are hemizygous for the bl...

Homeobox

...are called homeobox genes and form the homeobox gene family . A homeobox is about 180 base pairs lon... are the Hox genes , which are found in a special gene cluster, the HOX cluster . Hox genes function in patterning the body axis. Thus, by providing the i...