In Vitro Culture-Induced Pluripotency of Human Spermatogonial Stem Cells
Figure 2
Characterization of pluripotent stem cells within spermatogonial stem cell (SSC) clumps. (a) Morphology of spermatogonial stem cell (SSC) clumps after in vitro culture (upper: passage 1, lower: passage 5). (b) Alkaline phosphatase activity in SSC colonies after culture (passage 1 and passage 5). CHA-hES4 cells (human embryonic stem cell line, hESCs) were used as a positive control, and feeder cells were used as a negative control. (c) Immunocytochemical analysis of pluripotent stem cell markers (OCT4, SSEA-4, TRA 1–60 and TRA 1–81) was performed with SSC clumps at passage 1 (left panel) and passage 5 (right panel). (d) Colocalization of specific markers for pluripotent stem cells (SSEA-4, red color) and SSCs (GFR α1, green color) in the cultured SSC clumps (at passage 1). The red circle indicates a SSC in which both markers were co-expressed. The yellow circles indicates a mSSC in which pluripotent stem cell-marker were only expressed. Note: Mock 1st Ab; cultured cells stained with secondary antibody only as a negative control. Scale bars = 50 μm.
