TY - JOUR
T1 - Newer insights into premeiotic development of germ cells in adult human testis using Oct-4 as a stem cell marker
AU - Bhartiya, Deepa
AU - Kasiviswanathan, Sandhya
AU - Unni, Sreepoorna K.
AU - Pethe, Prasad
AU - Dhabalia, Jayesh V.
AU - Patwardhan, Sujata
AU - Tongaonkar, Hemant B.
PY - 2010/12
Y1 - 2010/12
N2 - The transcription factor octamer-binding transforming factor 4 (Oct-4) is central to the gene regulatory network responsible for self-renewal, pluripotency, and lineage commitment in embryonic stem (ES) cells and induced pluripotent stem cells (PSCs). This study was undertaken to evaluate differential localization and expression of two major transcripts of Oct-4, viz. Oct-4A and Oct-4B, in adult human testis. A novel population of 5- to 10-μm PSCs with nuclear Oct-4A was identified by ISH and immunolocalization studies. Besides Oct-4, other pluripotent markers like Nanog and TERT were also detected by RT-PCR. Adark spermatogonial stem cells (SSCs) were visualized in pairs and chains undergoing clonal expansion and stained positive for cytoplasmic Oct-4B. Quantitative PCR and Western blotting revealed both the transcripts, with higher expression of Oct-4B. It is proposed that PSCs undergo asymmetric cell division and give rise to Adark SSCs, which proliferate and initiate lineage-specific differentiation. The darkly stained nuclei in Adark SSCs may represent extensive nuclear reprogramming by epigenetic changes when a PSC becomes committed. Oct-4B eventually disappeared in mature germ cells, viz. spermatocytes, spermatids, and sperm. Besides maintaining normal testicular homeostasis, PSCs may also be implicated in germ cell tumors and ES-like colonies that have recently been derived from adult human testicular tissue.
AB - The transcription factor octamer-binding transforming factor 4 (Oct-4) is central to the gene regulatory network responsible for self-renewal, pluripotency, and lineage commitment in embryonic stem (ES) cells and induced pluripotent stem cells (PSCs). This study was undertaken to evaluate differential localization and expression of two major transcripts of Oct-4, viz. Oct-4A and Oct-4B, in adult human testis. A novel population of 5- to 10-μm PSCs with nuclear Oct-4A was identified by ISH and immunolocalization studies. Besides Oct-4, other pluripotent markers like Nanog and TERT were also detected by RT-PCR. Adark spermatogonial stem cells (SSCs) were visualized in pairs and chains undergoing clonal expansion and stained positive for cytoplasmic Oct-4B. Quantitative PCR and Western blotting revealed both the transcripts, with higher expression of Oct-4B. It is proposed that PSCs undergo asymmetric cell division and give rise to Adark SSCs, which proliferate and initiate lineage-specific differentiation. The darkly stained nuclei in Adark SSCs may represent extensive nuclear reprogramming by epigenetic changes when a PSC becomes committed. Oct-4B eventually disappeared in mature germ cells, viz. spermatocytes, spermatids, and sperm. Besides maintaining normal testicular homeostasis, PSCs may also be implicated in germ cell tumors and ES-like colonies that have recently been derived from adult human testicular tissue.
KW - Differentiation
KW - Embryonic stem cells
KW - Nuclear reprogramming
KW - Oct-4
KW - Oct-4A
KW - Oct-4B
KW - Proliferation
KW - Spermatogonia
KW - Testis
UR - http://www.scopus.com/inward/record.url?scp=78650162604&partnerID=8YFLogxK
U2 - 10.1369/jhc.2010.956870
DO - 10.1369/jhc.2010.956870
M3 - Article
C2 - 20805580
AN - SCOPUS:78650162604
SN - 0022-1554
VL - 58
SP - 1093
EP - 1106
JO - Journal of Histochemistry and Cytochemistry
JF - Journal of Histochemistry and Cytochemistry
IS - 12
ER -