Figure 4.

Establishing Nrf1 conditional-knockout ESCs and mouse model. A) NRF1 protein was examined by IHC. B) Transcript level of NRF1 was measured by real-time RT-PCR in CD9⁺/C-KIT⁻ spermatogonia, C-KIT⁺ spermatocytes, and haploid spermatids from wild-type adult testes. Data are means ± 1 sem from 4 biologic replicates. **P < 0.01. C) The NRF1 protein level was measured by Western blot and IHF in testes with conditional deletion of Nrf1 at P7, compared with their wild-type littermates. Arrowheads: the DDX4⁺ germ cells that were devoid of NRF1 expression in Nrf1^f/Δ-Cre testicle sections. Scale bars, 50 μm.