Locus (genetics)

From Wikipedia, the free encyclopedia

(Redirected from Short arm)
Jump to: navigation, search
Short and long arms
Short and long arms
Chromosome.(1) Chromatid. One of the two identical parts of the chromosome after S phase.(2) Centromere. The point where the two chromatids touch, and where the microtubules attach.(3) Short arm(4) Long arm.
Chromosome.
(1) Chromatid. One of the two identical parts of the chromosome after S phase.
(2) Centromere. The point where the two chromatids touch, and where the microtubules attach.
(3) Short arm
(4) Long arm.
Example of bands
Example of bands

In biology and evolutionary computation, a locus (plural loci) is a fixed position on a chromosome, such as the position of a gene or a biomarker (genetic marker). A variant of the DNA sequence at a given locus is called an allele. The ordered list of loci known for a particular genome is called a genetic map. Gene mapping is the process of determining the locus for a particular biological trait.

Diploid and polyploid cells whose chromosomes have the same allele at some locus are called homozygous, while those that have different alleles at a locus, heterozygous.

The chromosomal locus of a gene might be written "6p21.3".

Component Explanation
6 The chromosome number.
p The position is on the chromosome's short arm (p for petit in French); q indicates the long arm.
21.3 The numbers following the letter represent the position on the arm: band 21, sub-band 3. The bands are visible under a microscope when the chromosome is suitably stained. Each of the bands is numbered, beginning with 1 for the band nearest the centromere. Sub-bands and sub-sub-bands are visible at higher resolution.

A range of locations is specified in a similar way. For example, the locus of gene OCA1 may be written "11q1.4-q2.1", meaning it is on the long arm of chromosome 11, somewhere in the range of sub-band 4 of band 1, and sub-band 1 of band 2.

The ends of a chromosome are labeled "ptel" and "qtel", and so "2qtel" refers to the telomere of the long arm of chromosome 2.

 This genetics article is a stub. You can help Wikipedia by expanding it.
Retrieved from "http://en.wikipedia.org/wiki/Locus_%28genetics%29"
Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.