In-vitro fertilization in the mouse and the relevance of different sperm/egg concentrations and volumes

Abstract

The sperm:egg ration and sperm concentration were varied separately by using different volumes (1--100 microliters) and egg numbers (1--15). The % fertilization was determined by sperm concentration in large volumes (10--100 microliters). In small volumes (1 or 5 microliters) the number of spermatozoa/egg determined penetration rate: the effective epididymal sperm number/fertilization was 250--350. Spermatozoa obtained from the oviducts (i.e. naturally selected) gave good fertilization responses and low concentrations of epididymal spermatozoa were also more effective when oviducal fluid and cumulus cells were included in the inseminating volume. We conclude that sperm/egg collision rate is the most important factor determining % fertilization, although heterogeneity of epididymal spermatozoa limits fertilization rate at low sperm:egg ratios.

Maturation of hamster oocytes under chemically defined conditions and sperm penetration through the zona pellucida

“…Sperm concentration is a critical factor for achieving reasonable success of in vitro fertilisation (Fraser & Drury, 1975;Siddiquey & Cohen, 1982;Wolf et al, 1984). The sperm concentrations used for in vitro fertilisation range from about 1.0 x 10 4 to 1.0 x 10 7 sperm/ml, depending on the laboratory and the species used.…”

Fertilization of Sea Urchin Eggs and Sperm Motility Are Negatively Impacted under Low Hypergravitational Forces Significant to Space Flight1

“…Even though this last group of parameters was increased in hyperG, the role of these parameters in the net movement of sperm toward the egg may not be of as dramatic consequence in comparison to MOT and VSL. This would be true if sperm-egg collision rate is a factor [37,38]. If so, then it would be interesting to test whether increasing the sperm concentration would counteract the observed negative gravitation effect.…”

“…Displacements in the submicrometer range are sufficient to trigger changes in cytoskeletal reorientation [36]. The statoliths and protoplasts are of sufficient mass that the force produced by gravity interacts with cytoskeletal elements, which in turn cause changes in the direction of growth [37][38][39]. Furthermore, the interactions with the cytoskeleton are coupled to changes in cell signal transduction involving mechanosensitive changes in Ca 2ϩ [5,40,41].…”

Some factors influencing the interaction of ram spermatozoa with zona-free hamster eggs

“…In the subsequent experiments, the sperm-egg fusion rate in the gamete mixing system with paraffin oil was therefore improved by exposing the watch glasses, at the beginning of the interaction, to a C02-free atmosphere for 70-90 min instead of for about 30 min. The amount of medium used to study gamete interaction in vitro varies widely from 1 µ (Siddiquey & Cohen, 1982) to 4 ml . Siddiquey & Cohen (1982) found that very small volumes of 1-5 µ negatively affected the fertilization rate of mouse eggs in vitro.…”

“…The amount of medium used to study gamete interaction in vitro varies widely from 1 µ (Siddiquey & Cohen, 1982) to 4 ml . Siddiquey & Cohen (1982) found that very small volumes of 1-5 µ negatively affected the fertilization rate of mouse eggs in vitro. The metabolic activity of the gametes in such small volumes of medium might change the conditions of fertilization obtaining in larger volumes, i.e.…”