Testosterone control of male-type sexual behavior in the tammar wallaby (Macropus eugenii).
In the tammar wallaby, Macropus eugenii, the expression of male-type sexual behavior is apparently determined by the activating effects of testicular hormones in adulthood. The incidence of male-type copulatory behavior and sexual checking behavior was compared in intact (control) males, control females, testosterone-treated females, and three groups of males castrated either postnatally (24-26 days of age), prepubertally (14.5 months of age), or in adulthood. All three groups of castrated male wallabies showed a very low incidence of male sexual behavior in adult life, comparable to that shown by the untreated females. Adult female wallabies with 100-mg testosterone implants showed a high incidence of male sexual behavior which was indistinguishable from that shown by intact males. The results suggest that sex differences in male-type behavior in the tammar wallaby are due to short-term inductive effects of testosterone acting on a sexually indifferent brain. There is no evidence of any long-term organizational effects of testosterone acting in fetal or neonatal life on the neural pathways controlling male-type sex behavior in this marsupial mammal.
Rudd
C D
CD
Department of Physiology, Monash University, Clayton, Australia. CRudd@zoology.uq.edu.au
Short
R V
RV
Shaw
G
G
Renfree
M B
MB
D000818:Animals; D005260:Female; D007614:Macropodidae; D008297:Male; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D013739:Testosterone / Q000494:pharmacology*
D013739:Testosterone