In vitro fertilization of hamster and human oocytes by microinjection of human sperm

Abstract

In this study, swollen sperm heads were obtained after the injection of human sperm into the perivitelline space of hamster oocytes. The number of injected sperm and the sperm concentration in the preincubation medium were found to have an influence on the rate of penetrated hamster oocytes. The optimal injected sperm number was always between five to 12 to obtain 8, 37, and 36% penetration for donors A, B, and C, respectively. The optimal sperm concentration in preincubation medium was between 6 and 22 x 10(6) sperm/ml to obtain 16, 47, and 43% penetration for donors A, B, and C, respectively. The rate of polyspermic oocytes was related to the injected sperm number (0, 55, and 100% for one to four, five to 12, and more than 12 injected sperm respectively). Ten human mature oocytes were injected with the sperm from six normal donors. Five fertilized eggs were obtained, and of these four cleaved in in vitro culture.

Effects of glutathione (GSH and GSSG) and glutathione reductase (GR) on zona‐free hamster oocyte ability to decondense human sperm

“…Without seeing swollen sperm nuclei, it would be very difficult to evaluate whether the eggs have been penetrated by spermatozoa." Thus, the PR ratio that we have used in the present study, as in previous studies [Lassalle et al, 1987;Lassalle and Testart, 19881, reflects the proportion of hamster oocytes with decondensed sperm nuclei rather than that of penetrated oocytes.…”

Development of human male pronucleus: Ultrastructure and timing

“…On the other hand, our results have shown that sperm nuclei can develop into morphologically normal pronuclei in the cytoplasm of aged human oocytes, provided that the barrier to sperm penetration represented by the hardened zona pellucida is removed. An efficient method for negotiating the zona pellucida by microinjection of spermatozoa directly into the perivitelline space of human eggs has been described [Lassalle et al, 1987 J. This method may still have some chance of success in oocytes in which fertilization has not been achieved by previously attempted standard IVF procedure.…”

Current Status and Future of Micromanipulation-Assisted Fertilization in Animals and Human.

“…This specific technique of SUZI evolved from animal studies that demonstrated that fertilization and development to birth of healthy live young [3] was possible. Fertilization of human oocytes [24][25][26] and human pregnancies [4] and live births [27] stimulated an increase in the clinical use of this procedure for patients who had failed to achieve fertilization in vitro and for patients with too few (or only immotile) spermatozoa to even attempt in vitro fertilization [28,29]. Pavasuthipaisit et al [30] compared fertilization and embryo development in cattle after SUZI and ICSI, and obtained a higher fertilization with ICSI, although the embryonic development to the hatched blastocyst stage was similar in both groups.…”