Polygenic Inheritance


Also found in: Medical.

polygenic inheritance

[‚päl·i‚jen·ik in′her·əd·əns]
(genetics)
The phenotypic expression of a trait involving the interaction of many genes.

Polygenic Inheritance

 

the determination of one complex character by nonallelic genes called polygenes, which have a cumulative effect. Under different environmental conditions, polygenic inheritance leads to a continuous, or quantitative, variation of the character in a biological population.

Most characters are quantitative, for example, an organism’s size, weight, color, and sometimes, resistance to disease, as well as many economically important properties possessed by agricultural animals, for example, the yield and fat content of milk in cows, the clip and color of wool in sheep, and the egg-laying capacity and egg size in chickens.

Polygenic inheritance was discovered in 1909 by the Swedish scientist H. Nilsson-Ehle, who studied the inheritance of grain color in wheat by the analytical dissociation of the character. However, the classical Mendelian approach to the study of polygenic inheritance is of very limited value since it is impossible to single out clearly defined types of organisms following their qualitative characters. The study of quantitative traits is based on statistical methods. Having revealed the natural pattern of inheriting qualitative characters, the theory of polygenic inheritance has contributed to the theory of evolution and has acquired great importance in the selection of plants and animals.

REFERENCES

Rokitskii, P. F. Vvedenie v statisticheskuiu genetiku. Minsk, 1974.
Kempthorne, O. An Introduction to Genetic Statistics. New York-London, 1957.
Mather, K., and J. L. Jinks. Biometrical Genetics: Study of Continuous Variation, 2nd ed. London, 1971.

L. A. ZHIVOTOVSKII

References in periodicals archive ?
A number of cases are now recognised as familial, and within affected families the disorder exhibits either an autosomal recessive pattern of inheritance or a polygenic inheritance pattern, ie involving several genes and the environment.
These core concepts include basic mechanisms of gene expression and regulation, an expanded vision of the nature of environment, principles of polygenic inheritance, and competing systems of gene expression.
This mechanism, in which more than one gene contributes to a given outcome, is called polygenic inheritance (Watson et al.
Vitiligo exhibits familial clustering in a non-Mendelian pattern that most likely reflects multifactorial, polygenic inheritance.
On the other hand, if ADHD is an example of polygenic inheritance with variable expressivity of some of the genes involved, influenced by as-yet-undetermined environmental factors, then how we look at its diagnosis becomes a question of the degree of ADHD rather than a disease.
On the other hand, the distribution did not approach normality, as would be expected in classic polygenic inheritance.
Tests on quantitative traits of skeletal morphology, assumed to be controlled by polygenic inheritance, strongly suggest that overall rates of morphologic divergence in several major taxa largely reflect stabilizing selection acting on a background of random mutation and drift (Turelli et al.
Glaucoma is a chronic progressive neurodegenerative disease and exhibits heterogeneity, polygenic inheritance, and incomplete penetrance.
A diverse spectrum of naturally occurring resistance against sedentary nematodes has been described ranging from simply inherited dominant genes to recessive polygenic inheritance.