Submitted to: Biology of Reproduction Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 23, 1999
Publication Date: June 19, 1999
Citation: Song, J.H., Rohrer, G.A., Wise, T.H., Ford, J.J. 1999. Developmental transcription of androgen receptor in hypothalamus-pituitary-testicular axis of boars [abstract]. Biology of Reproduction. 60 (Supplement 1):234. (Abstract #454) Technical Abstract: The androgen receptor (AR) which is located on the X chromosome was chosen as a candidate gene that may regulate testicular development and sperm production in boars. In the current study developmental changes in AR gene expression were evaluated for possible association with poor negative feedback control of luteinizing hormone in neonatal male pigs (Ford and Schanbacher, Endocrinology 100:1033, 1977). Hypothalami, pituitaries and testes were collected from fetuses (n=10, Day 105 of gestation) and boars at 10 days of age (n=9) and adulthood (n=6). AR mRNA was detected by reverse transcription and polymerase-chain reaction (RT-PCR), and its protein was localized by immunocytochemistry (ICC). Both RT-PCR and ICC indicated that neither AR transcripts nor protein were detected in the pituitary from fetuses and piglets at day 10 of age, whereas AR transcripts were observed at significantly greater (P>0.01) steady-state concentrations in pituitary from adult boars. AR transcripts were expressed in the testes of boars at all ages; however, AR protein was only observed in adult testes by ICC. Low levels of AR mRNA were also observed in hypothalamus tissue from the fetuses, piglets and adult boars. These results indicate that the basis for the dysfunctional negative feedback control of luteinizing hormone in neonatal male pigs is the absent or low concentration of AR in the pituitary gland.