Molecular patterns of sex determination in the animal kingdom: a comparative study of the biology of reproduction

Table 2 Different aspects of sex differentiation in marsupials

	Y chromosome (testes)	No Y chromosome (absence of testes)
One X chromosome (scrotum)	XY	XO
	Male animals with scrotum and testes	Animals without testes and an empty scrotum instead of a pouch
Two X chromosomes (pouch and mammary glands)	XXY	XX
	Animals with testes and a pouch with mammary glands instead of scrotum	Female animals with a pouch and mammary glands

The marsupial Y has the ability to turn the undifferentiated gonads into testes, but other aspects of sex differentiation seem to rely on the number of X chromosomes present. This is how we come across the above combinations in sex chromosome aneuploidies in marsupials.

ISSN: 1477-7827