Age-related and photoperiodic variation of the DAZ gene family in the testis of the Syrian hamster (Mesocricetus auratus)

Abstract

The Deleted in AZoospermia (DAZ) gene family regulates the development, maturation andmaintenance of germ cells and spermatogenesis in mammals. The DAZ family consists of two autosomalgenes, Boule and Dazl (Daz-like), and the Daz gene on chromosome Y. The aim of this study was toanalyze the localization of DAZL and BOULE during testicular ontogeny of the seasonal-breedingSyrian hamster, Mesocricetus auratus. We also evaluated the testicular expression of DAZ family genesunder short- or long-photoperiod conditions. In the pre-pubertal and adult testis, DAZL proteinwas found mainly in spermatogonia. BOULE was found in the spermatogonia from 20 days of ageand during the pre-pubertal and adult period it was also detected in spermatocytes and roundspermatids. DAZL and BOULE expression in spermatogonia was strictly nuclear only in 20-dayoldhamsters. We also detected the novel mRNA and protein expression of BOULE in Leydig cells.In adult hamsters, Dazl expression was increased in regressed testis compared with non-regressedtestis and DAZL protein expression was restricted to primary spermatocytes in regressed testis. Theseresults show that DAZL and BOULE are expressed in spermatogonia at early stages in the Syrianhamster, then both proteins translocate to the cytoplasm when meiosis starts. In the adult regressedtestis, the absence of DAZL in spermatogonia might be related to the decrease in germ cell number,suggesting that DAZ gene family expression is involved in changes in seminiferous epithelium during photoregression.