Enhancement of acrosome reaction and subzonal insemination of a single spermatozoon in mouse eggs

Abstract

The acrosome reaction in mouse spermatozoa was induced by various means. These were 1) varying incubation time in T6 medium, 2) incubation in T6 medium with added A23187, 3) incubation in T6 medium with added dbcGMP and imidazole, 4) exposure to an electric field, and 5) a combination of incubation in a medium with dbcGMP and imidazole and electroporation. The mean percentages of acrosome-free spermatozoa obtained by these various methods and assessed on the basis of both Bryan's stain and immunolocalization by FITC-labeled monoclonal antibodies increased by steps from 36% to 67%, 73%, 86%, and 92%. Individual spermatozoa from the various treatments were afterwards microinjected under the zona pellucida of a mouse oocyte. The fertilization rate for eggs microinjected with a spermatozoon treated with A23187, dbcGMP, and imidazole, by electroporation and by a combination of the last two methods also increased by steps from 17% to 34%, 36%, and 70%, respectively. Ninety-five percent of the fertilized oocytes reached the early blastocyst stage, thirty-eight percent of these blastocysts implanted in pseudopregnant mice, and twenty-eight percent developed to term. These results indicated the varying degrees of success of different ways of inducing acrosomal loss in spermatozoa and their subsequent success rates in fertilization and further in vitro and in vivo development.

Development and current applications of assisted fertilization

“…Later, mechanical insertion of spermatozoa directly into the perivitelline space-subzonal sperm injection (18)-appeared as another way of overcoming inadequacies of sperm concentration and motility, and proved to be more effective than zona drilling or partial zona dissection, particularly after prior induction of the acrosome reaction (19)(20)(21).…”

The pioneering of intracytoplasmic sperm injection: historical perspectives

“…In this technique (Fig. 1, Panel A), up to 3 spermatozoa were brought with an injection pipette through the ZP and deposited into the perivitelline space of a metaphase-II oocyte (Ng et al 1988, Palermo & Van Steirteghem 1991. The initial results of SUZI were encouraging.…”

“…Much of the oocyte damage was attributed to the crudeness of the micromanipulation instruments (Pereira et al 2016). Furthermore, because sperm injection bypassed ZP-sperm fusion, oocyte activation was required in most species, which was generally achieved by vigorous suction of ooplasm just before sperm injection (Perreault & Zirkin 1982) or with compounds such as A23187 (Palermo & Van Steirteghem 1991).…”

The Historic Development and Incorporation of Four Assisted Reproductive Technologies Shaping Today′s IVF Industry

“…Most individuals are familiar with the breakthrough efforts of an Italian Physician, Dr. Gianpiero Palermo, experimenting with sperm injection at the Universitair Ziekenhuis fertility clinic in Brussels, Belgium, where the first human birth was reported in 1992 [92,93]. Like other scientists of his day, he initiated his Reproductive career in male infertility studies with sub-zonal insemination [94] in the mouse model [95] as well as working with discarded immature human oocytes. In late 1991, the latter preliminary investigations yielded unexpected outcomes.…”