Question

Which of the following statements about sex determination in Drosophila is false?

		Transformer along with transformer-2 regulates the splicing of double-sex RNA.
		The sex-lethal (Sxl) gene is transcribed in female fly embryos, but not in male fly embryos.
		Only males make functional transformer protein.
		Double-sex RNA is spliced differently in males and females.

Answer 1

In the sex determination of drosophila the sxl gene is transcribed in females and not in males. Also the Dsx RNA is spliced differently in females mediated by Tra and Tra-2 proteins and in males by Tra-2.

In males the functional Tra protein is not made, rather it is made in females from a functional Sxl protein that helps in the splicing and formation of proper tra protein.

Thus the statement, that only males make functional transformer protein (option 3) is false in case of drosophila sex determination.