Polygene

Polygene or polygenic trait refers to a trait that is controlled by a group of non-allelic genes, known as polygenes. These traits exhibit a continuous distribution, such as height or skin color in humans. Polygenes are a key aspect of quantitative genetics, which studies traits that vary continuously.

Overview

Polygenes are typically spread out across different chromosomes. Each polygene typically has a small effect individually, but together they can significantly influence the phenotype. This is in contrast to Mendelian inheritance, where traits are controlled by a single gene and exhibit a discontinuous distribution.

Polygenic Traits

Polygenic traits are those that are controlled by more than one gene, such as height, skin color, and eye color in humans. These traits do not follow the simple Mendelian inheritance patterns. Instead, they show a bell-shaped distribution in a population, with most individuals inheriting a combination of dominant and recessive alleles.

Polygenic Inheritance

Polygenic inheritance is a type of non-Mendelian inheritance. It involves the interaction of multiple genes to produce a phenotype. The phenotype is the result of additive effects, dominance and epistasis of different genes. The concept of polygenic inheritance was first proposed by the German geneticist Hermann Nilsson-Ehle at the beginning of the 20th century.

Polygenes and Disease

Many common diseases, such as diabetes, asthma, and cancer, are polygenic. This means they are influenced by multiple genes, in combination with environmental factors. Understanding the role of polygenes in disease can help in the development of treatments and preventative measures.

See Also

• Quantitative trait locus
• Genetic linkage
• Genome-wide association study