Question

Sexually reproducing organisms use a variety of strategies to compensate for the gene dosage differences arising from different numbers of X-chromosomes present in males and females. Please describe how dosage compensation of X-chromosome is achieved in mice and Drosophila?

Answer 1

In MICE Dosage compensation is achieved by inactivation of 1X chromosome in homogametic sex(XX)

In Drosophila Dose compensated by hyperactivation of X chromosome in male ( Male specific lethal gene produces Msl proteins in males.Msl proteins are involved in euchromatization of X chromosome.In females Sexlethal proteins Synthesized which target transcript of Sxl genes,tra genes and Msl gene.Sxl proteins blocks Msl 2 mRNA translation so in females msl2 protein absent .