Diapause, pregnancy, and parturition in Australian marsupials

Abstract

Marsupial pregnancy is characterised by a long lactation and a relatively short gestation. Marsupials have, in effect, exchanged the umbilical cord for the teat. However, gestation can be extended for up to 11 months by the imposition of a period of developmental arrest known as embryonic diapause. Diapause may be under either lactational or seasonal control, and in the kangaroos and wallabies these effects are mediated by prolactin and melatonin, respectively. At the other end of gestation, namely parturition, it appears that marsupials are fairly typical mammals and require all the same physiological and behavioural cues essential for the delivery of a viable young. Parturition depends on ..