FBXO24 deficiency in mice impairs sperm histone-to-protamine exchange.
(A) SEM images show the abnormality of Fbxo24 KO sperm head. AA, anterior acrosome; EQ, equatorial segment; PAS, postacrosomal segment; VS, ventral spur; HR, hook rim. Scale bars = 2 μm. (B) TEM images show the decondensed nucleus (Nu) of Fbxo24 KO sperm. Scale bars = 1 μm. (C) Western blot analysis of the expression of histones (H2A, H2B, H3, and H4), transition proteins (TNP1), and protamines (PRM2) from WT and Fbxo24 KO sperm are shown. GAPDH serves as a loading control. Quantification of protein levels in (C). Error bars represent mean ± S.D., n = 3. *, p < 0.05. (E) Western blot analysis of the expression of indicated proteins in WT and Fbxo24 KO testis. GAPDH serves as a loading control. (F) Quantification of protein levels in (E). Error bars represent mean ± S.D., n = 3. *, p < 0.05.