In situ localization of rat testis-specific calcineurin B subunit isoform beta 1 in the developing rat testis

In situ localization and developmental changes in expression of testis-specific calcineurin B subunit isoform beta 1 was examined in rat testis. Two different sizes of mRNA signal, 4.0 kb and 0.9 kb, were detected by Northern blot hybridization. Both signals were expressed synchronously with the start of meiosis at 3 weeks after birth, and increased depending on the maturation of spermatogenesis. In situ hybridization using non-radioactive riboprobes showed that the beta 1 mRNA was specifically localized to spermatocytes where meiosis occurs but none or very little was observed in spermatogonia, spermatids, Sertoli or Leydig cells.