Can some one please explain to me epistatic varience? I am studying Narrow-Sense Heritablity and how to determine which heritable factors are due to additive traits.
This is for a general Genetics course design for Biology majors.This class is taken in the junior year.
Sorry. Epistatsis occurs when one gene has been silenced or mutated by another set of genes. Epistasis takes place at the phenotypic level. Depending on which genes combined during meiosis, the phenotype can change. An example of epstasis is the coat color in horses. The variety in coat colors stems from modifer gene called cream dilution that dilutes the color of the coat. Cream dilution makes red gene appear yellow due to it diluting qualities. I hope this helps!
Narrow-sense heritability is a measure of the effects that genotypes have on phenotypic expression in terms of additive traits. Additive traits are traits that multiple alleles that code for the same trait. For example, there is more than one allele for skin color and hair color. Depending on which genes on turned on or off, the expression of the different alleles are controlled by factors that control gene expression. Some of these genes are epistasis, mutations, methylation, etc. Factors that affect additive traits are the number of alleles, how close they are in proximity (frequency of recombination), dominance and recessive, type of allele, location of allele on chromosome (condensed or un-condensed regions).