Fig. 1From: Unusual interplay of contrasting selective pressures on β-defensin genes implicated in male fertility of the Buffalo (Bubalus bubalis)SSRs in the MRT. Spermatozoa undergo extensive remodelling of their surface in the epididymis where several proteins are adsorbed, inserted and bound covalently or non-covalently on its surface. These include- i) the epididymal coat proteins (ECPs) which may be deep-seated in the plasma membrane via the hydrophobic interactions, ii) electrostatically bound proteins iii) Glycosyl-phosphatidylinositol (GPI) anchored proteins and proteins interacting with them iv) proteins in apical blebs known as epididymosomes that are embedded in the sperm plasma membrane and are usually trans-membrane. The seminal plasma proteins (SPPs) and the de-capacitation factors are finally added in the seminal fluid before ejaculation. In the FRT, the capacitation induced changes in the outer sperm membrane cause loss of many proteins e.g. DEFB-126, in a site-specific manner. (Adapted and modified from Rich TD, and Turman EJ.–Beef Cattle Handbook-2200) [37]Back to article page