AGB 121: Principles of Animal Genetics and Population Genetics (2+1)

EFFECTS OF LETHAL GENES

• Some lethal genes induce gross abnormalities, some interfere with physiological processes and others kill or are not yet been identified. They produce lethal effect in homozygous state.
• Lethal action may be due to single gene or at times more than a single gene.
• Expressed lethal effect is due to environment, incomplete penetrance and variable expressivity and epistasis.
• In majority of cases, it is difficult to determine the type of gene action.