Dictionary > Allelic exclusion

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.


You will also like...

Adaptation Tutorial
Adaptation Tutorial

Adaptation, in biology and ecology, refers to the process or trait through which organisms or the populations in a habit..

Fossil trilobite imprint in the sediment
Insects

There are more species of insects than any other species combined. This surely illustrates that insects have the selecti..

human respiratory system
Respiration

The human respiratory system is an efficient system of inspiring and expiring respiratory gases. This tutorial provides ..

The Human Physiology
The Human Physiology

Physiology is the study of how living organisms function. Thus, human physiology deals specifically with the physiologic..

Biological Energy
ATP & ADP – Biological Energy

ATP is the energy source that is typically used by an organism in its daily activities. The name is based on its structu..

Disturbance on a still water
Abiotic Factors – Water Conditions

A still body of water may be disturbed by a variety of factors. One of them is wind. In fact, it is considered as the pr..