- It is the phenomenon of one gene affecting more than one character.
- Eg: Sickle cell anemia, white eye gene in Drosophila
a) Lethal gene action:
- Some time , the pleiotropic gene effect produces various abnormal ability in phenotypic feature which are collectively called syndromes.
- When the pleiotropic gene cause further death of the individual then it is called lethal gene.
- This lethal gene is either in a homozygous condition (dominant)or homozygous recessive condition.
- It is of following types: Dominant lethal. Recessive lethal, conditional lethal, Balanced lethal and gametic lethal.
b) Semi lethal gene action:
- < 10% individuals survive.
- Eg: xantha mutants.
c) Vital gene action:
- Don’t affect the survival of the individuals.
- Neither enhance nor reduces the viability.
d) Sub vital gene action:
- Reduces viability.
- Kill less than 90% individuals .
- Eg: Mutant species.
e) Super vital gene action:
- Enhance the survival of the individual.
- Eg: disease resistance , insect resistance and other resistance.
Join the conversation