A Comparison of the Effects of Pentoxifylline on Quality of Fresh and Frozen-thawed Bull Spermatozoa

[Object]This study aimed to examine the effects of 3,7-dimethyl-1-（5-oxo-hexyl）-xanthine（pentoxifylline,PF）on the motility,mitochondrial activity,acrosome integrity and fertilization rate of spermatozoa in both fresh and frozen-thawed bull semen.[Method]Fresh and frozen-thawed bull spermatozoa were exposed to 5 mmol/L PF with untreated samples as controls.[Result]Fresh spermatozoa showed reduced（P〈0.05）motility after 2 h incubation with PF whereas,surprisingly,frozen-thawed samples exhibited increased sperm motility（P〈0.05）after 2 h incubation with PF and they also showed enhanced longevity compared to controls.Mitochondrial activity in both fresh and frozen-thawed bull spermatozoa increased（P〈0.05）during 4 h incubation with PF whereas acrosome integrity remained unchanged in both types of semen.However,treatment with 5 mmol/L PF did not influence the in vitro fertilization efficiency of fresh spermatozoa but improved significantly（P〈0.05）that of frozen-thawed spermatozoa.[Conclusion]These results indicate that PF can improve sperm quality of frozenthawed bull semen,and may improve pregnancy rates in bovine artificial insemination programmes employing frozen semen.

Effect of PMSG/hCG Superovulation on Mouse Embryonic Development

Kunming mouse strain is widely used in China, and the superovulation was administrated with 10 IU PMSG combined with 10 IU hCG. In this study, the effects of the exogenous gonadotropins on superovulation of Kunming mice and embryo quality derived from the superovulated mice were assessed. Female mice at 6-8-wk old were superovulated with 0, 5, 7.5 and 10 IU PMSG/hCG and mated with male mice. The embryos were retrieved at 2.5 d post coitum. No statistic difference was observed for the number of 2-cell embryos collected per mouse between control and 5 IU PMSG/hCG treatment group, but the number significantly increased for 7.5 and 10 IU PMSG/hCG treatment group （P〈0.05）. The average number of 4- cell and 8-cell embryos collected from each mouse significantly differed between control and 5, 7.5, 10 IU PMSG/hCG treatment groups （P〈0.05）. When 8-cell embryos derived from mice administrated with 0, 5, 7.5 and 10 IU PMSG/hCG were cultured in KSOM, the blastocyst development rates were 88.1, 94.7, 96.1 and 94.3%, respectively, which were similar to control （P〉0.05）. This indicated that exogenous gonadotropins have no effects on development of Kunming mouse embryos. The quality of blastocyst was assessed by labelling with Hoechst and propidium iodide for inner cell mass and trophectoderm cells, the result showed that ICM/TE ratio significantly decreased for 10 IU PMSG/hCG treatment group compared with control, 5 and 7.5 IU PMSG/hCG treatment group （P〈0.05）. This suggested that the embryo quality of Kunming mouse has been affected by high dose of gonadotropins.

Cloning,Sequencing and Analysis of DDX3Y Gene in Five Male Equus Animals

[ Objective] This study analyzed the differences in DDX3 Y gene sequences among male horse, male donkey, male mule, male hinny and male foal to investigate the relationship between DDX3Y gene structure and the mechanism of infertility in male Equus fetus × asirms. [ Method] Partial sequences of DDX3Y gene in male horse, male donkey, male mule, male hinny and male foal were obtained by genome comparison, sequencing and cloning, and compared by bioinformatics methods. [ Result] The CDS regions varied in 5 base pairs and two amino acids. DDX3Y protein was predicted to be an unstable protein. In addition, the results also showed that DDX3 Y gene in male horse displayed a closer phylogenetic relationship to male mule and male foal; DDX3Y gene in male donkey displayed a closer phylogenetic relationship to male hinny. [ Conclusion] This study provided scientific basis for further exploring the function of DDX3 Y gene and the mecha- nism of reproductive regulation in male Equus ferus × asinus.