Table 2. Sex-specific expression in male and female heterogametic systems.
Male |
Female |
|||||
---|---|---|---|---|---|---|
Genotype | Expression | Fitness | Genotype | Expression | Fitness | |
Male heterogamety (XY) | R | zm | RR | zf | ||
RM | zf+δf | |||||
M | zm+δm | MM | zf+2δf | |||
Female heterogamety (ZW) | RR | zm | R | zf | ||
RM | zm+δm | |||||
MM | zm+2δm | M | zf+δf |
The resident allele (R) has expression level zm in males and zf in females. The mutant allele (M) causes a small quantitative shift of δm and δf in males and females, respectively.