Caracterização morfológica e bioquímica do ânulo nuclear de espermatozoide bovino

Abstract

The sperm nuclear matrix has the critical role in regulation of DNA fragmentation and degradation before and after fertilization, and paternal DNA replication after fertilization. In order to better understand the organization of the nuclear matrix sperm of bulls the annulus nuclear the nuclear matrix of bovine sperm was isolated and visualization in scanning electron microscopy were measured its length and width. With the isolation of the nuclear annulus, it was found that in this bull sperm has an elliptical shape with the mean length and width 1.10 μm and 0.54 μm respectively. In addition, histochemical analysis allowed characterization of the annulus, as a nuclear structure glycoprotein complexed with DNA and MALD-TOF showed that the complex is formed by any of numerous proteins with high molecular weight. Among these proteins, there are some high molecular weight (about 400 kDa), as identified in bovine genome but not yet characterized. There are other proteins (KTR9 and microtubule-associated protein), which suggest that the annular structure is trans nuclear envelope and other that suggests it participates in the process of chromatin condensation (MGC127041, MGC137211), and morphogenesis (KRT9 and DPY19L2) of the head during spermiogenesis.