Figure 5

Different but both germ cell-specific expressions of nanos1A and nanos1B in dogfish testis. The cellular distribution of nanos1 mRNAs was evaluated by in situ hybridization on dogfish testicular sections with antisense digoxigenin-conjugated riboprobes directed against nanos1A (A–F) or nanos1B transcripts (A’–F’). a and a’ represent sense riboprobes ISH for nanos1A and nanos1B respectively. The nanos1A transcripts were detected in the potential SSC (filled arrow) and in undifferentiated spermatogonia (open arrow) of the zone A0 (B), in the spermatogonia (SPG) of zone A- (C,D) as well as in the primary spermatocytes (SPCI) of the zone B (E) and in the round spermatids (rSPT) of the zone C (F left panel). No signal was observed in the elongated spermatids (eSPT) of the zone D (F right panel) nor in the Sertoli cells (their nuclei are indicated by SN). The nanos1B transcripts were mainly detected in the potential SSC (filled arrow), the undifferentiated spermatogonia (open arrow) of zone A0 (B’) and in spermatogonia (SPG) of zone A- (C’,D’). A marked decrease in nanos1B expression was observed in the primary spermatocytes (SPCI) of zone B (E’) and no transcript was present in the germ cells of zone C (F’ left panel) and zone D (F’ right panel). Aspecific labelling was observed in Sertoli cells nuclei of zone D using nanos1B riboprobes (F’ right panel). L: lumen of the cyst; A, A’: overview of zone A of testis.