Detection of growth factors in the testis of roe deer (Capreolus capreolus)

Roe deer is a seasonal breeder characterised by a short rutting season in s ummer. Mature males show synchronised cycles of testicular involution and r ecrudescence. Therefore, this species is a valuable model to study seasonal regulation of spermatogenesis in ruminants. It is hypothesised that a time -dependent production of testicular growth factors is required to regulate seasonal changes in testis growth and spermatogenesis. To identify potentia l candidates, total RNA from roe deer testis tissue was extracted at three different seasonal periods (April, August, December), and using RT-PCR the presence of several growth factors (aFGF, bFGE IGF-I, IGF-LT, TGF-alpha, TG F-beta (1), TGF-beta (3) and two isoforms of VEGF) was detected. Sequencing of the growth factor PCR fragments revealed a high sequence homology betwe en cattle and roe deer. To further explore the expression patterns of the i dentified growth factors in roe deer their expression levels were standardi sed using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene expression. The study demonstrates the expression of several growth factors in roe dee r testis and supports the assumption of their seasonally diverse regulation . These results provide the basis to investigate the role of growth factors in the regulation of circannual changes of testicular activity. (C) 2000 E lsevier Science B.V. All rights reserved.