Dominant and recessive epistasis [closed]. Ask Question. Asked 5 years ago. Can anyone clarify my confusion about that the epistasis seen in "Labradors , an example of recessive or dominant epistasis? ? I am not getting definite results . SHARE. Epistasis definition. The genes responsible for expression of the trait in the phenotype. In the case of simple Mendelian inheritance each gene is responsible for the expression of only one phenotypic trait. But, in reality the situation is more complicated. Epistasia o epistasis (de origen griego que significa interrupcion): es un tipo de interaccion entre genes situados en distintos loci en un mismo cromosoma que consiste en que un gen puede enmascarar o suprimir la expresion del otro. Epistasis - modification of dihybrid inheritance by interaction of genes (NOT ALLELES). Same as dihybrid inheritance but genes interact. F1 same as one dominant parent but new phenotypes in F2. F2 = 9:3:3:1 ratio but can be modifications. Epistasis often involves pigment pathways. Use your knowledge of epistasis to determine the genotypes of offspring in the following crosses Part A In freshwater snails, pigment color is influenced by two genes. If two heterozygous pigmented freshwater snails were crossed and offspring were produced in a ratio of 9 pigmented snails to 7 If this problem persists please contact customer support.