To date, there are no protocols optimized to the effective separation of spermatogonial stem cells (SSCs) from testicular cells derived from mouse testes, thus hindering studies based on mouse SSCs. In this study, we aimed to determine the most efficient purification method for the isolation of SSCs from mouse testes among previously described techniques. Isolation of SSCs from testicular cells derived from mouse testes was conducted using four different techniques: differential plating (DP), magnetic-activated cell sorting (MACS) post-DP, MACS, and positive and negative selection double MACS. DP was performed for 1, 2, 4, 8, or 16 h, and MACS was performed using EpCAM (MACSEpCAM), Thy1 (MACSThy1), or GFR α1 (MACSGFRα1) antibodies. The purification efficiency of each method was analyzed by measuring the percentage of cells that stained positively for alkaline phosphatase. DP for 8 h, MACSThy1 post-DP for 8 h, MACSGFRα1, positive selection double MACSGFRα1/EpCAM, and negative selection double MACSGFRα1/α-SMA were identified as the optimal protocols for isolation of SSCs from mouse testicular cells. Comparison of the purification efficiencies of the optimized isolation protocols showed that, numerically, the highest purification efficiency was obtained using MACSGFRα1. Overall, our results indicate that MACSGFRα1 is an appropriate purification technique for the isolation of SSCs from mouse testicular cells.

Sirt1 belongs to class III histone/protein deacetylase. Sirt1 KO mice have spermatogenic defects. In this study, expression of Sirt1 and acetylated histone 3k9 (H3k9ac) was examined in developing mouse testes. Among two splicing variants of sirt1 mRNA long form was dominant in developing testis. Testicular sirt1 mRNA levels were low at birth, increased until 14 days post partum (pp) and remained constant thereafter. Sirt1 immunoreactivity was weak to negligible in gonocytes, moderate in spermatogonia, absent in preleptotene spermatocytes, moderate in zygotene spermatocytes, strong in pachytene spermatocytes, and weak in diplotene spermatocytes. Round and elongating spermatids were negative for Sirt1. Acetylated histone 3k9 (H3k9ac) immunoreactivity was moderate in spermatogonia and weak to negligible in preleptotene to pachytene spermatocytes but strong in round and elongating spermatids. In Sertoli cells, nuclear Sirt1 immunoreactivity was absent at birth, increased at 14 days pp and markedly increased at 28 days pp onwards. In immature Sertoli cells culture, FSH and testosterone increased sirt1 mRNA, suggesting that Sirt1 participates in protein deacetylation events during the differentiation of Sertoli cells by gonadotropin. In the Leydig cells, nuclear Sirt1 immunoreactivity was weak until 2 weeks pp and decreased in 4 weeks pp onward. suggesting the protein deacetylation by Sirt1 in Leydig cell precursor/progenitor cells. Mutually exclusive expression between Sirt1 and H3k9ac in pachytene spermatocytes in testis suggests that deacetylation of H3K9ac by Sirt1 participates in the gene silencing and/or chromosome behavior in pachytene sspermatocytes.

Mature mammalian oocytes are ovulated at the metaphase II stage of meiosis and complete the cell cycle by fertilization with sperm. During fertilization sperm release an egg activation protein, pho-spholipase C zeta (PLCZ) into oocyte cytoplasm, PLCZ hydrolyze PIP2 into IP3 and DAG. The elevation of IP3 concentration induces Ca2+ release from endoplasmic reticulum (ER) by binding to the IP3 receptor (IP3R) on the membrane of ER. Recent studies have shown that sperm from patients lacking expression of PLCZ1 or expressing mutant forms of PLCZ1 fail to induce [Ca2+]i oscillations or oocyte activation. Purified recombinant human PLCZ1 (hPLCZ1) protein evaluated its [Ca2+]i oscillation activity in mouse and human oocytes. Here we investigated that produced mouse PLCZ-specific antibodyrecognized the PLCZ protein in mouse testes. PLCZ antibody was raised in rabbits against 19-mer sequence at the C-terminus (MENKWFLSMVRDDFKGGKI) of mouse PLCZ protein. Sperm were fixed in 3.7% paraformaldehyde followed by permeabilization. Sperm were incubated in 5% normal goat serum (NGS) and then incubated overnight with anti-mouse PLCZ. Peanut agglutinin (PNA)-lectin was used for detection of the acrosome. Mouse testes from 6~8 weeks old ICR mouse were fixed in 10% formalinand serial sectioned at 5~8um. Testes tissues were immunostained with anti PLCZ antibody and peanut agglutinin(PNA) for acrosome staining. Produced anti mouse PLCZ antibody recognized 74 kDa protein in western and PLCZ is localized to the post-acrosomal region of mouse sperm and to the equatorial region of bull sperm. Mouse PLCZ protein wasdetected on spermatocytes, spermatid, but not on spermatogonia in seminiferous tubules. Some residual bodies on sperm neck and tail showed strong signal of PLCZ, but this staining was still present with antigenic peptide pretreatment to reduce non specific antibody reaction. Also this antibody reacted with the apical region (arrowheads) of principal cells, where secretory vesicles accumulate on the epididymal tissue. But antigenic peptide pretreatment did not remove this apical region staining. This study presents PLCZ protein is localized on the post-acrosomal region or equatorial region of mouse and bull sperm head. Also PLCZ protein in mouse testes expressed from spermatocytes to mature sperm on later stage of spermatogenesis.