Androgen-Driven Sequestration

Science Signaling  11 Dec 2012:
Vol. 5, Issue 254, pp. ec320
DOI: 10.1126/scisignal.2003853

Male and female mice differ in the neuronal patterns that serve the mammary glands. Liu et al. now describe how gonadal hormones drive development of distinct male and female sensory innervations. Although both male and female mammary glands develop their sensory innervation similarly in early embryogenesis, once the androgens take effect, the developmental trajectories diverge. By birth, the rich network of sensory neurons present in the female is absent in the male. Androgens cause a switch from expression of the full-length neurotrophin receptor TrkB to its truncated form, TrkB.T1, both of which are expressed on the neurons. In males, truncated TrkB.T1 sequesters brain-derived neurotrophic factor (BDNF) from further activity, whereas in females, full-length TrkB binds BDNF and supports neuronal development.

Y. Liu, M. Rutlin, S. Huang, C. A. Barrick, F. Wang, K. R. Jones, L. Tessarollo, D. D. Ginty, Sexually dimorphic BDNF signaling directs sensory innervation of the mammary gland. Science 338, 1357–1360 (2012). [Abstract] [Full Text]