Epifazis

Epifazis is a term used in genetics and developmental biology to describe the phenomenon where a gene's expression is modulated by the presence of other genes. It refers to the ability of one gene to influence the phenotypic expression of another gene. This interaction can lead to a modified or altered outcome of the trait that the second gene controls.

Epifazis is distinct from simple dominance or recessiveness, where one allele masks the expression of another allele at the same locus. Instead, epifazis involves interactions between alleles at different genetic loci. For example, a gene might produce an enzyme that is required for the function of a protein encoded by another gene. If the first gene is not expressed or is mutated, the second gene's protein might not be produced or might not function correctly, leading to a phenotype that is determined by the first gene, not the second.

This type of gene interaction is crucial for understanding complex traits that are influenced by multiple genes. It explains why individuals with similar genotypes for a particular gene might exhibit different phenotypes, depending on their genetic background. Studying epifazis helps researchers map gene networks and understand the intricate regulatory mechanisms that govern development and disease.