Abstract: | This study was conducted to determine whether reproductive failures in ageing, obese lethal yellow (Ay/a) females are due primarily to defects within Ay/a ovaries or to systemic defects which may operate outside the ovaries. Reciprocal ovary transplantation between control (a/a) and lethal yellow (Ay/a) females provided an experimental system to test the reproductive potential of not only Ay/a ovaries in control (a/a) females but also control (a/a) ovaries in mutant (Ay/a) females. Results on reproductive performance of all four combinations of grafts between Ay/a and a/a mice proved that Ay-induced reproductive failures are not due to intrinsic ovarian lesions but rather to defects operating extrinsically to the ovary. The hypothalamo-pituitary axis is a likely site for this reproductive lesion. |