3.6. Immunolocalization of proteins involved in meiosis
initiation during spermatogenesis
To explore the potential function of the identified differentially
expressed proteins during meiosis initiation, PDCD4, for
which high-quality antibodies were available, was chosen for
further immunolocalization investigation. PDCD4 was found
expressed in the spermatogonia at both PND 8.5 and PND 10.5
(Fig. 5A and B). More seminiferous tubules were found to have
PDCD4 positive spermatogonia at PND 10.5 compared with
PND 8.5 (50.22% vs. 37.3%, Fig. 5C). And for PDCD4 positive
seminiferous tubules, we found the ratio of PDCD4 positive
cells was also higher at PND 10.5 (17.61% at PND 10.5 vs. 9.65%
at PND 8.5, Fig. 5D). Thus, Pdcd4 may function during the
differentiation of spermatogonia during testis development.
4. Discussion
There are strong and extensive evidences to suggest that RA is a
key regulator of germ cell differentiation and meiosis initiation
in bothmale and femalemammalian gonads [7,8]. However, the
detailed mechanisms and the genes and proteins downstream
of RA have not yet been comprehensively explored. In the
male germ line, a series of developmental events occur within
the first 10 days after birth. In this study, we used H&E staining