Allelic exclusion

Allelic exclusion
(Science: cell biology, genetics) The process whereby one or more loci on one of the chromosome sets in a diploid cell is inactivated (or destroyed) so that the locus or loci is (are) not expressed in that cell or a clone founded by it.
For example in mammals one of the x chromosome pairs of females is inactivated early in development (see Lyon hypothesis) so that individual cells express only one allelic form of the product of that locus. Since the choice of chromosome to be inactivated is random, different cells express one or other of the x chromosome products resulting in mosaicism.
The process is also known to occur in immunoglobulin genes so that a clone expresses only one of the two possible allelic forms of immunoglobulin.

This tutorial describes the independent assortment of chromosomes and crossing over as important events in meiosis. Read..

Animals adapt to their environment in aspects of anatomy, physiology, and behavior. This tutorial will help you understa..

Seed plants are vascular plants. They differ from the other vascular plants in producing seeds that germinate into a new..

This tutorial elaborates on how the nervous system works, particularly at the tissue level of the brain. There are three..

Plants in lentic habitats have features not found in terrestrial plants. They acquired these features as they adapt to t..

This tutorial noted some of the physical and chemical factors that provide the framework of a running water community in..

You will also like...