CatSper-null mutant spermatozoa are unable to ascend beyond the oviductal reservoir

Sperm hyperactivation is characterised by high-amplitude, asymmetrical flagellar bending and is required to penetrate the oocyte zona pellucida. It was proposed that hyperactivation also enables spermatozoa to reach the oocyte by assisting escape from the oviductal sperm reservoir. To test this hypo...

Full description

Saved in:

Bibliographic Details
Published in:	Reproduction fertility and development Vol. 21; no. 2; p. 345
Main Authors:	Ho, Katharine, Wolff, Collin A, Suarez, Susan S
Format:	Journal Article
Language:	English
Published:	Australia 01-01-2009
Subjects:	Animals Calcium Channels - deficiency Calcium Channels - genetics Copulation Ejaculation Female Male Mice Mice, Inbred ICR Mice, Knockout Oviducts - anatomy & histology Ovulation Seminal Plasma Proteins - genetics Sperm Capacitation Sperm Motility Spermatozoa - metabolism Time Factors
Online Access:	Get more information
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Sperm hyperactivation is characterised by high-amplitude, asymmetrical flagellar bending and is required to penetrate the oocyte zona pellucida. It was proposed that hyperactivation also enables spermatozoa to reach the oocyte by assisting escape from the oviductal sperm reservoir. To test this hypothesis, the behaviour of CatSper-null mouse spermatozoa in the oviduct was compared with that of spermatozoa from heterozygotes. CatSper(-/-) males are infertile because their spermatozoa fail to hyperactivate, whereas spermatozoa from CatSper(+/-) males have normal amounts of CatSper proteins and can hyperactivate. Males were mated with wild-type females on the morning of ovulation. Oviducts were obtained 1 or 4 h later, and behaviour of spermatozoa was examined using transillumination. At 1 h, null mutant spermatozoa remained attached by their heads to oviductal epithelium in the reservoir, whereas spermatozoa from heterozygotes detached from the oviductal epithelium after performing deep asymmetrical flagellar bends. At 4 h, 50 to 200 CatSper(+/-) spermatozoa were still seen in the oviducts; in contrast, only one CatSper(-/-) spermatozoon was found. CatSper(-/-) spermatozoa were lost from the oviducts after failing to detach from the epithelium in a timely manner, thus demonstrating that hyperactivation is required by spermatozoa to ascend beyond the oviductal reservoir.
ISSN:	1031-3613
DOI:	10.1071/rd08183