The tammar wallaby: a model to examine endocrine and local control of lactation.

Marsupials, such as the tammar wallaby (Macropus eugenii), have adopted a reproductive strategy that is very different to eutherians. Both the rate of production and the composition of milk changes progressively during the lactation cycle to meet the nutritional demands of an altricial young. The tammar therefore provides a valuable model to study changes in milk composition, and in particular the genes that code for proteins secreted in the milk, to more accurately assess the role of gene products regulating either development of the young or mammary function.