Question

K gene in mice is known to be paternally imprinted (paternal copies are silenced) and expressed during embryogenesis. A mutation occurred on the promoter of K gene and this promoter lost its ability to bind to RNA polymerase. A female mouse is heterozygous for this mutant allele and the wild-type allele of K gene. If this female produces embryos by mating with a male, which is also heterozygous at this locus, what proportions of male and female embryos will express K protein? Why?

Answer 1

K gene is said to paternally silent in offspring but same is active when inherited from the mother .When a cross is made between female mouse heterozygous for k mutant allele and male mouse heterozygous in same way then offsprings will inherit wild type k allele from father and produce no protein but when wild type k allele is inherited from mother it is expressed so 50 percent male offsprings and 50 percent Female offsprings will expressed K protein . Below is the image for showing cross .

eMe S ブ ten CoP1 a chive s+ 孕 50% mnoften