FIGURE 6:

Msi-1 protects Sertoli cells against apoptosis induced by heat treatment. (A) No apoptotic Sertoli cells were observed in the untreated group (a) and Msi-1–silenced group (b). Heat stress induced a significant increase in the number of apoptotic Sertoli cells (green signals) in the Msi-1–silenced group (d) but not in the control siRNA group (c). Scale bars: 40 μm. (B) In the single-treatment groups (heat stress or Msi-1 siRNA), the protein levels of Fas, FasL, Bax, caspase-3, caspase-8, and caspase-9 were not increased and were similar to those of untreated Sertoli cells. However, these cell proapoptotic markers were significantly increased in Msi-1–knockdown Sertoli cells upon exposure to heat stress. The protein levels were normalized to β-tubulin.