Primary genetic-control of sexual-differentiation in marsupials
G Shaw, MB Renfree, RV Short
Australian Journal of Zoology | Published : 1989
Marsupials, like eutherians, normally require the presence of a Y chromosome for testicular formation. However some sexually dimorphic characters such as the scrotum, mammary anlagen, gubernaculum and processus vaginalis appear to be under direct genetic rather than secondary hormonal control. Scrota1 development occurs where only a single X chromosome is functional, whilst two X chromosomes are necessary for pouch formation.