“Position effect”的意思、由来-开放百科全书

词条

Position effect

释义

References
External links

Position effect is the effect on the expression of a gene when its location in a chromosome is changed, often by translocation. This has been well described in Drosophila with respect to eye color and is known as position effect variegation (PEV).^[1]

The phenotype is well characterised by unstable expression of a gene that results in the red eye coloration. In the mutant flies the eyes typically have a mottled appearance of white and red sectors. These phenotypes are often due to a chromosomal translocation such that the color gene is now close to a region of heterochromatin. The heterochromatin can spread stochastically and switch off the color gene resulting in the white eye sectors.

Position effect is also used to describe the variation of expression exhibited by identical transgenes that insert into different regions of a genome. In this case the difference in expression is often due to enhancers that regulate neighboring genes. These local enhancers can also affect the expression pattern of the transgene. Since each transgenic organism has the transgene in a different location each transgenic organism has the potential for a unique expression pattern.

References

1. ^{{cite journal |vauthors=Weiler K, Wakimoto B |title=Heterochromatin and gene expression in Drosophila |journal=Annu Rev Genet |volume=29 |issue= 1|pages=577–605 |year= 1995|pmid=8825487 |doi=10.1146/annurev.ge.29.120195.003045}}

External links

{{cite book |chapter=Figure 4-45. Position effects on gene expression in two different eucaryotic organisms |chapterurl=https://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4.figgrp.665 |author=Alberts, Bruce |title=Molecular biology of the cell |publisher=Garland Science |location=New York |year=2002 |isbn=0-8153-4072-9 |url=https://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4 |edition=4th}}

1 : Epigenetics

随便看

开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。