Polygenic trait

Polygenic Trait

A Polygenic Trait is a trait that is controlled by a group of non-allelic genes, known as polygenes. These traits are also known as quantitative traits or multifactorial traits. Polygenic traits are the physical characteristics that are influenced by more than one pair of genes and their interaction with the environment.

Overview

Polygenic traits are governed by two or more genes on different chromosomes. Each gene adds a small amount to the trait, and the combined effect of these genes produces a continuous range of phenotypes. Examples of polygenic traits include skin color, height, and body mass index (BMI).

Polygenes

Polygenes are groups of genes that work together to produce a specific trait. Each polygene typically has a small effect individually, but together they can significantly influence the phenotype. Polygenes can interact with each other and with environmental factors to produce a wide range of phenotypes.

Genetic Variation

Polygenic traits contribute to the genetic variation within a population. The distribution of these traits often forms a bell curve, with most individuals exhibiting an intermediate phenotype and fewer individuals exhibiting extreme phenotypes. This pattern of distribution is known as normal distribution.

Environmental Influence

The expression of polygenic traits can be influenced by the environment. For example, nutrition can affect height, and sun exposure can affect skin color. This interaction between genes and the environment is known as gene-environment interaction.

Genetic Disorders

Some genetic disorders are also polygenic. These include conditions such as heart disease, high blood pressure, and type 2 diabetes. These disorders are influenced by multiple genes and environmental factors.

See Also

• Genetics
• Gene
• Phenotype
• Genotype
• Gene-environment interaction