No abstract

The hemizona assay is a diagnostic test used to evaluate the binding potential of spermatozoa to zonae pellucida and has been used to predict fertilization potential in the human. In this study, frozen-thawed gorilla spermatozoa were coincubated with human hemizonae to evaluate tight binding and to assess the use of human zonae in evaluating sperm fertility. Matching hemizonae were incubated with human sperm to serve as a control. For evaluation of binding studies in a homologous system, matching halves of gorilla hemizonae were coincubated with both gorilla and human sperm. Whole, intact zonae of both human and gorilla oocytes were also coincubated with heterologous sperm to determine if penetration into the perivitelline space could occur. This study found that gorilla sperm bound well to both gorilla and human hemizonae, with a mean of 112.5 and 81.0 tightly bound sperm, respectively. Human sperm also bound to gorilla (mean 229.5) and human (mean 236.5) hemizonae. Following incubation with intact gorilla zonae, motile human sperm were found within the perivitelline space. However, gorilla sperm were not visible within the perivitelline space of nonviable human oocytes. These findings demonstrate that the zonae of nonviable human oocytes can be used to assess sperm binding of gorilla sperm. Studies continue for optimizing assay condition and correlation of findings with the fertility potential of gorilla sperm.

FSH binding to Sertoli cells is required for optimal production of sperm in mammals. The cAMP response element-binding protein (CREB) is a major mediator of FSH-induced changes in gene expression. To determine whether CREB is required for spermatogenesis, an adenovirus encoding a phosphorylation-defective CREB mutant (AdCREBm1) was used to inhibit CREB activity in Sertoli cells. Addition of AdCREBm1 to primary rat Sertoli cell cultures completely abolished induction of the CREB-regulated c-fos gene. Injection of an adenovirus encoding ss-galactosidase into the rat testis seminiferous tubules in vivo demonstrated that predominately Sertoli cells were infected by adenovirus. AdCREBm1-directed expression of CREBm1 in seminiferous tubules did not affect Sertoli cell viability, but resulted in the apoptosis of meiotic spermatocyte germ cells within 4 days of adenovirus injection into seminiferous tubules. Disrupted spermatogenesis, defined by at least a 75% reduction of round spermatids, was observed in 42 +/- 5.8% of seminiferous tubules 14 days after AdCREBm1 infection, whereas using this criteria, testes injected with a control adenovirus did not display disrupted spermatogenesis. These data demonstrate that AdCREBm1 causes apoptosis and elimination of germ cells and suggest that CREB is required to produce a Sertoli cell-derived factor that is critical for germ cell survival.

Preincubation of sperm in milk therefore appears to enhance their ability to penetrate zona-free hamster oocytes, compared to TESTY preincubation. Since milk is natural, simple, inexpensive, readily available, and can be easily processed, it should be the medium of choice for sperm preincubation.

Background: The safety and tolerability of a new highly purified, urine-derived human menopausal gonadotropin (hMG) preparation [Menopur(R)] was compared with a currently available hMG [Repronex (R)] in women undergoing in vitro fertilization (IVF).