Gene
Genes are entities that parents pass to offspring during reproduction . These entities encode information essential for the construction and regulation of polypeptides , proteins and other molecules that determine the growth and functioning of the organism .
The word "g...
Albinism
...xternal links
Lack of pigmentation
The
gene which results in albinism prevents the body from m...aneous albinism, individuals inherit an "albinism
gene " from both parents. Where an individual receives one albinism
gene and one normal gene, that person will not show out...
Allele
... one of a number of alternative forms of the same
gene occupying a given locus (position) on a chromosome . An example is the
gene for blossom color in many species of flower - a single
gene controls the color of the petals, but there may be...
Allele frequency
... population , or equivalently the richness of its
gene pool . Allele frequency is defined as follows:
Given a) a particular chromosome locus , b) a
gene occupying that locus, c) a population of individu...
The frequencies of all the alleles of a given
gene often are graphed together as an allele frequency...
Alternative splicing
...to a modification of the definition of a "gene". Some have proposed that a
gene should be considered as a twofold information structure:
A DNA sequenc... of coding.
Others have noted that it is unnecessary to change the DNA of a
gene for the evolution of a new protein. Instead, a new way of regulation coul...
Antibody
...ntigens, it must produce millions of B lymphoyctes. It is important to note that to produce such a diversity of antigen binding sites with a separate
gene for each possible antigen, the immune system would require many more genes than exist in the genome . Instead, as Susumu Tonegawa showed in 1976, ...
Apoptosis
...m carried out by human papillomaviruses (HPV), a
gene called E6 is expressed in a product that degrade... (IFN-alpha/beta)induce transcription of the p53
gene , resulting in the increase of p53 protein level ...ced-3 and ced-4 .
Ron Ellis also identified a
gene with an opposite effect: ced-9 . The product of t...
Autosome
...omes or, less frequently, as gonosomes.
Uses
An autosomal dominant
gene is one on an autosome and is always expressed, even if a single copy exists. The chance is 1:2 for passing this
gene to offspring.
...
Bacterial conjugation
...plasmid carries a tra and a trb locus , which together are about 33 kb long and consist of about 40 genes . The tra locus includes the pilin
gene and controlling genes, which together form pili on the cell surface, polymeric proteins that can attach themselves to the surface of F-negative ...
Barr body
...his can be significant if different alleles of a
gene are present on the different chromosomes; in some ...t evidence suggests that the maternally inherited
gene may be imprinted .
It is thought that this cons...ion of CpG sites . These changes help inactivate
gene expression on the inactive X-chromosome and to br...
Biology
...
A phylogenetic tree of all living things , based on rRNA
gene data, showing the separation of the three domains bacteria , archaea , a...g organisms on Earth are descended from a common ancestor or ancestral
gene pool . This "last universal common ancestor, that is, the most recent comm...
Biodiversity
...-Leste, and the United States of America.
If the
gene is the fundamental unit of natural selection, thus...ganisms . They study processes such as mutations,
gene exchanges, and genome dynamics that occur at the D...nd genetic engineering , people are going through
gene patenting , processes patenting, and a totally ne...
Bioinformatics
...t , protein structure prediction , prediction of
gene expression and protein-protein interactions , and..."shotgun" DNA sequencing , and the prediction of
gene regulation with data from mRNA microarrays or...he huge amounts of DNA data (pictured) produced by
gene sequencing projects is just one of the tasks faced...
Biophysics
...fforts are included in some biology department somewhere. To include some:
gene regulation , single protein dynamics, bioenergetics, patch clamping , bio... slicing) as well as theoretically (computer models), membrane permitivity,
gene therapy, understanding tumors.
Pharmacology and physiology - channel ...
BLAST
...e, following the discovery of a previously unknown
gene in the mouse , a scientist typically will perform...uences in the human genome that resemble the mouse
gene based on similarity of sequence.
BLAST is one ...ller at The Pennsylvania State University , and
gene Myers at the University of Arizona . It is avai...
Cancer
...ombinations of treatments, or new methods such as
gene therapy .
A clinical trial is one of the final s...rited. Inheriting certain mutations in the BRCA1
gene renders a woman much more likely to develop breas...rry some oncogene or tumor suppressor inactivating
gene in their genome .
It is impossible to tell the ...
Cilium
...um in the renal tube cells can lead to polycystic kidney disease (PKD). In another genetic disorder called Bardet-Biedl syndrome (BBS), the mutant
gene products are the components in the basal body and cilia.
...
Cloning
...logy , cloning is used in two contexts: cloning a
gene , or cloning an organism . Cloning a
gene means to extract a
gene from one organism (for example by PCR) and insert ...
Genetic code
...onal portion of this molecule is referred to as a
gene . Each
gene is transcribed into a short template molecule of... which will then be folded into a protein .
The
gene sequence inscribed in DNA, and in RNA, is composed...
Common descent
...or . In biology , the theory of universal common descent proposes that all organisms on Earth are descended from a common ancestor or ancestral
gene pool.
A theory of universal common descent based on evolutionary principles was proposed by Charles Darwin in his book The Origin of Species ...
Bioinformatics
...t , protein structure prediction , prediction of
gene expression and protein-protein interactions , and..."shotgun" DNA sequencing , and the prediction of
gene regulation with data from mRNA microarrays or...he huge amounts of DNA data (pictured) produced by
gene sequencing projects is just one of the tasks faced...
Culture
... aspects of culture can best be understood through the concept of the meme , first introduced by Richard Dawkins in his 1976 book The Selfish
gene . The idea is that there are units of culture, memes , roughly analogous to genes in evolutionary biology . Although this view has gained some po...
Defective interfering particle
..., DIPs cannot sustain an infection by themselves. Instead, they depend on coinfection with a suitable helper virus. The helper virus provides the
gene functions that are absent from the DIPs.
...
Down syndrome
...n aging similar to that of Alzheimer's disease .
Another chromosome 21
gene that might predispose Down syndrome individuals to develop Alzheimer's pathology is the
gene that encodes the precursor of the amyloid protein . Neurofibrillary tangle...
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 zy...selves around the periphery of the cell cytoplasm.
gene expression in these nuclei is regulated by the Bic...
Endosymbiotic theory
...netics , 16 (7), pp. 315-320. (Discusses theories on how mitochondria and chloroplast genes are transferred into the nucleus, and also what steps a
gene needs to go through in order to complete this process.) [1]
Paul Jarvis (2001), "Intracellular signalling: The chloroplast talks!", Current Biol...
Enhancer
...y even be reversed without affecting its function. Furthermore, an enhancer may be excised and inserted elsewhere in the chromosome, and still affect
gene transcription.
...
Epigenetics
...omosome inactivation in mammalian females, and
gene silencing within an organism.
The study of heritable changes in
gene function that occur without a change in the seque...
In both cases, the object of study includes how
gene regulatory information that is not expressed in DN...
Eugenics
...hibiting race mixing in an attempt to maintain the
gene pool. Eugenic considerations also lay behind the a...sire to exclude "inferior" races from the national
gene pool. In the early part of the twentieth century t...were inferior races who would pollute the national
gene pool if their numbers went unrestricted. It is arg...
Evolution
...a change in the frequency of an allele within a
gene pool . This change may be caused by a number of di...enetic drift or changes in population structure (
gene flow ).
Contents showTocToggle("show","hi... Natural selection
1.3.2 Genetic drift
1.3.3
gene flow
1.4 Microevolution and macroevolution...
Evolutionary developmental biology
...ovelty may arise through several methods including
gene duplication and
gene regulation.
gene duplication allows fixation of a particular cell...
Ewens's sampling formula
...tates that under certain conditions (specified below), if a random sample of n gametes is taken from a population and classified according to the
gene at a particular locus then the probability that there are a 1 alleles represented once in the sample, and a 2 alleles represented twice, ...
Exon
... Exons are the regions of DNA within a
gene that are not spliced out and which are retained in the final mRNA mole...ecific portion of the complete protein , however, not all exons in a given
gene will end up in the final protein due to the process of alternative splicin...
Expressed sequence tag
.... It was originally intended as a way to identify
gene transcripts , but has since been instrumental in
gene discovery and sequence determination. An EST is pr...ng probes for DNA microarrays used to determine
gene expression .
External links
The NCBI H...
Extinction
...it is sometimes possible for a deleterious mutation to be spread throughout a population through the effect of genetic drift .
A diverse or "deep"
gene pool gives a population a higher chance of surviving an adverse change in conditions. Effects that cause or reward a loss in genetic diversity can...
Genetic drift
...distributions; rather, they are a random sample, and are thus subject to the same statistical fluctuations (sampling error ).
When the alleles of a
gene do not differ with regard to fitness, on average the number of carriers in one generation is proportional to the number of carriers in the last. But t...
Gene duplication
...
gene duplication occurs when an error in DNA replicat...region of DNA containing a (generally functional)
gene . The significance of this process for evolutionary biology is that if a
gene is under natural selection , most mutations wil...
Gene pool
... The
gene pool of a species or a population is the comp...ing member of that species or population. A large
gene pool indicates a large genetic diversity , which ...xtinction .
When many alleles exist for a given
gene or locus , a population is said to be polymorphi...
Genetic code
...onal portion of this molecule is referred to as a
gene . Each
gene is transcribed into a short template molecule of... which will then be folded into a protein .
The
gene sequence inscribed in DNA, and in RNA, is composed...
Gene therapy
...
gene therapy is the insertion of genes into an indiv...ess. Antisense therapy is not strictly a form of
gene therapy, but is often lumped together with them.
..."show","hide")
1 Background
2 Types of
gene therapy
2.1 Ex vivo
2.2 In vivo
...