Question

What is the difference between Pleiotropy and Epistasis?

Answer 1

Hint: When a single gene exhibits multiple phenotypic effects, the condition is known as Pleiotropy. Epistasis refers to a condition, when a gene in a different location changes the expression of a gene in another location. Epistasis occurs when the activity of a gene is altered by one or more other genes. When one gene determines multiple phenotypes, is known as Pleiotropy. So, one gene contributes to many traits.

Complete answer:
Epistasis can be defined as an interaction between two genes in which the effect or product of an allele of one gene is affected by the action of alleles of another gene. Pleiotropy occurs when one gene affects more than one phenotypic trait. Some genes affect many different traits. They don’t code for a single feature.
The basic difference between epistasis and pleiotropy is that epistasis is the phenomenon in which a gene at one site changes the phenotypic expression of a gene at another location whereas pleiotropy explains the phenomenon in which a single gene affects several phenotypic traits.
Epistasis and pleiotropy are two phenomena in genetics. When more than one gene determines a single phenotype, epistasis occurs. Thus, in epistasis, one gene affects the expression of another located at a different location. In contrast, pleiotropy occurs when a single gene determines multiple phenotypes. Thus, one gene contributes to several traits. Both epistasis and pleiotropy are variants of Mendelian inheritance.

Note:
Symptoms associated with sickle cell disease are due to pleiotropic effects. People with sickle cell disease are homozygous for the mutant allele that produces sickle cell disease. Because sickle cell red blood cells provide less oxygen to the tissues, sickle cell disease has many pleiotropic effects. Symptoms include pain in the back, long bones and chest. Additional symptoms develop as the disease progresses.