Question

In mammals, the Sry gene on the Y chromosome is instrumental in the male sex determination process. However, in Drosophila, the Y chromosome is not associated with male sex determination, but it contains genes required for sperm development in the adult. The copy number of the X chromosome is linked to sex determination. Drosophila with two X chromosomes (e.g., XX) are female, and those with one X chromosome (e.g., XY) are male.
What would be the resultant phenotype of an XO Drosophila genotype?

Answer 1

The resultant phenotype of an XO Drosophila genotype would be a sterile male. This is because the X chromosome contains genes required for both female development and fertility in Drosophila. In the absence of a second X chromosome (as in the XO genotype), the individual would develop as a male but would be sterile due to the lack of necessary genes on the missing X chromosome for normal sperm development.