Comparative proteomic identification of capacitated and non-capacitated sperm of Yanbian Yellow Cattle.

To investigate the proteomic differences between the capacitated and non-capacitated sperm of the Yanbian yellow cattle, semen was collected from three Yanbian yellow cattle, aged 3-5 years, pooled, and divided into capacitated and non-capacitated groups (n = 9) to be analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and liquid chromatography-mass spectrometry. Gene ontology enrichment, Kyoto Encyclopedia of Genes and Genomes pathway enrichment, and protein-protein interactions were used for bioinformatics analysis. The results showed that 598 were described as differentially expressed proteins during sperm capacitation. In the capacitated sperm, 89 proteins were up-regulated, and 509 proteins were downregulated, compared to the non-capacitated sperm. Western blot analysis confirmed that the expression of the Heat Shock 70-kDa Protein 5 (HSPA5) proteins was down-regulated. After HSPA5 inhibition, the level of tyrosine phosphorylation decreased, and the cleaved caspase 3 increased. The results showed that HSPA5 could regulate sperm capacitation and slow down apoptosis. Thus, providing a basis for studying the changes in protein expression during sperm capacitation, which can help identify the marker proteins potentially related to sperm capacitation. Hence, this study can deepen our understanding of the molecular processes involved in the sperm capacitation in Yanbian yellow cattle and provide a framework for future research.

Inhibition of deubiquitinases alters gamete ubiquitination states and sperm-oocyte binding ability in pigs.

This study was undertaken to investigate the dynamics of protein ubiquitination in pig gametes and their micro-environments, as well as to explore the action of deubiquitinases (DUBs) in sperm-oocyte binding. Protein ubiquitination states were evaluated by in the ejaculated sperm, seminal plasma, epididymal sperm, oocytes, zona pellucida (ZP) and follicular fluid (FF) by western blotting. Different concentrations of PR-619, a non-selective inhibitor of DUBs, were used to treat oocytes during in vitro maturation (IVM), the maturation rate, amount of ubiquitinated ZP proteins, and ZP solubility were assessed. The PR-619 was also used to treat sperms during capacitation, then the ubiquitinated amounts of acrosin inhibitor (AI) proteins were evaluated. The number of sperm attached to the ZP of each oocyte was subsequently determined after gamete co-incubation. The study indicates the existence of ubiquitinated proteins (76kDa) in sperm, seminal plasma, oocytes, and follicular fluid (FF). The amount of ubiquitinated ZP proteins changed as growth of follicles progressed. Treatment with PR-619 at 10 and 15µM concentrations during IVM reduced the maturation rate of pig oocytes (P<0.05), while treatments with 10µM of PR-619 extended the ZP dissolution time (P<0.05). Treatment with PR-619 enhanced AI ubiquitination and improved amounts of 30-kDa ubiquitinated proteins (P<0.05). Treatment with PR-619 at the 10µM dose effectively reduced the number of sperm attached to per oocyte (P<0.05). Ubiquitinated proteins were present in gametes and their micro-environments. The DUBs were important in regulating pig gamete ubiquitination and sperm-oocyte binding.

[Effect of mold temperature on mechanical properties of Ti-Zr alloy castings].

OBJECTIVE: To investigate the influence of mold temperature on the mechanical properties of Ti-Zr alloy castings. METHODS: Ti-Zr alloy was cast into a mold which was made of a zircon (ZrO2.SiO2) investment with a casting machine (China) designed as vacuum, pressure and centrifuge. At three mold temperatures (room temperature, 300 degrees C, 600 degrees C) the Ti-Zr alloy was cast separately. The ultimate tensile strength (sigmab), 0.2% offset yield point strength (sigma0.2), and elongation to fracture (delta) were determined by a universal testing machine with 15 mm pre-marked gauge interval. The surface micro-structures of Ti-Zr alloy castings at three mold temperatures were observed by optical microscope. RESULTS: At a higher mold temperature during casting, the tensile strength and yield strength of Ti-Zr alloy were significantly increased, while the elongations were significantly decreased. The micro-structure of the surface was different from the inner part. There was a reacted layer in the outermost surface. The thickness of reacted layers at the three mold temperatures was about 35.5 man (room temperature), 55.0 microm (300 degrees C) and 65.5 microm (600 degrees C), respectively. The inner part of microstructure composed of main a phases within the prior alpha grain boundaries. CONCLUSION: The mold temperature is one of the major factors influencing Ti-Zr alloy mechanical properties. Comparing with Ti6Al4V alloy and Co-Cr alloy castings, Ti-Zr alloy is more suitable for denture frame.