FERTILIZATION AND DEVELOPMENT OF MOUSE OOCYTES INJECTED WITH MEMBRANE-DAMAGED SPERMATOZOA

The objective of this study was to investigate the influence of sperm plasma membrane on fertilization and development in a mouse model. The sperm plasma membrane was destroyed by exposure to Triton X-100 prior to intracytoplasmic sperm injection (ICSI). A single sperm curling (S SC) test was used to evaluate cell viability. The fertilization rates of oocytes obtained following ICSI of membrane-damaged sperm was not s ignificantly higher than that of the control group (62.4 versus 59.6%) . Rates of development to blastocyst were also not significantly diffe rent (51.7 and 50%). Inner cell mass (ICM) and total embryo cell numbe rs in the two groups were not statistically different(16 +/- 3.7 versu s 14.73 +/- 3.35 and 45.8 +/- 12.5 versus 39.5 +/- 12 respectively). T here were no differences in the implantation and live fetus rates betw een the two groups after transfer to pseudopregnant mice (61.5 and 35. 9% respectively for the membrane-damaged group and 53.5 and 31.4% for the intact group). In conclusion, the present study clearly shows that destruction of the sperm plasma membrane does not affect fertilizatio n and further development following injection of membrane-damaged sper matozoa into mouse oocytes. Fertilization and development can be achie ved by dead spermatozoa at an early stage of necrosis when only the pl asma membrane has been damaged.