1. Increased zona-binding ability after incubation of spermatozoa with proteins extracted from spermatozoa of fertile semen
- Author
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Dacheux F, P. Lopes, P. Sagot, Dacheux Jl, Barriere P, and Jean M
- Subjects
Male ,endocrine system ,Embryology ,medicine.medical_treatment ,Semen ,Fertilization in Vitro ,Biology ,Insemination ,Andrology ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Human fertilization ,medicine ,Humans ,Zona pellucida ,Zona Pellucida ,reproductive and urinary physiology ,030304 developmental biology ,Sperm-Ovum Interactions ,0303 health sciences ,030219 obstetrics & reproductive medicine ,In vitro fertilisation ,urogenital system ,Proteins ,Obstetrics and Gynecology ,Cell Biology ,Oocyte ,Spermatozoa ,Follicular fluid ,Sperm ,medicine.anatomical_structure ,Reproductive Medicine ,Culture Media, Conditioned ,Female - Abstract
The involvement of proteins extracted from spermatozoa of fertile semen in sperm-zona binding was examined under hemizona assay conditions. One droplet of a suspension of spermatozoa was exposed to sperm proteins and then tested for zona binding, while a parallel semen suspension droplet incubated with culture medium served as a control. The reliability of the test was increased by relating the number of spermatozoa bound to each inseminated hemizona to the surface area of the hemizona and expressed as the binding index. For spermatozoa incubated with extracted proteins, the binding index was greater than (P = 0.001) that of controls (125.2 +/- 45.1 versus 63.6 +/- 29.2, respectively). As a first control, two other protein sources (fetal calf serum and human follicular fluid) were tested in the hemizona assay. No significant differences were found in zona binding for other protein-exposed spermatozoa compared with controls. As a second and reverse control, exposure of one hemizona to sperm proteins before insemination with untreated spermatozoa induced a marked decrease (P = 0.0003) in sperm binding, compared with that of the matched hemizona not exposed to sperm proteins (control) (3.4 +/- 1.4 versus 74.5 +/- 6.8, respectively). Taken together, these findings confirm the involvement of extracted sperm proteins in sperm-zona interactions. Therefore, in the cases in which fertilization in vitro fails because of a lack of sperm-zona binding, incubation of deficient spermatozoa with proteins extracted from spermatozoa of fertile ejaculates should restore their ability to interact with the oocyte and, thus, should enhance the prognosis for in vitro fertilization.
- Published
- 1995