Development of the Adrenal Gland in the Tammar Wallaby, Macropus Eugenii (Desmarest) (Marsupialia: Macropodidae).

Abstract

The adrenal of the male tammar wallaby first appears at day 21 of embryogenesis as a nodule of tissue lying close to the anterior pole of the kidney. The nodule consists of adrenocortical tissue in that its cells contain an active 3 beta ol-steroid dehydrogenase from about day 22 of embryogenesis. From day 22 of embryogenesis until at least day 20 of pouch life a sympathetic nerve plexus is adpressed to the medial side of the adrenal. Cells migrate from the plexus through pores in the capsule of the gland and intermingle with the cortical cells. By day 7 of pouch life some of the invading cells display a chromaffin reaction and by day 60 have formed a distinct medulla. The cortex shows the beginnings of zonation by day 60 of pouch life but the three adult zones are not seen until day 200.