scholarly journals Mammalian egg coat modifications and the block to polyspermy

2020 ◽  
Vol 87 (3) ◽  
pp. 326-340 ◽  
Author(s):  
Eileen Fahrenkamp ◽  
Blanca Algarra ◽  
Luca Jovine
Keyword(s):  
Egg Coat

Complementarity between sperm surface β-l,4-galactosyl-transferase and egg-coat ZP3 mediates sperm–egg binding

Nature ◽  
1992 ◽  
Vol 357 (6379) ◽  
pp. 589-593 ◽  
Author(s):  
David J. Miller ◽  
Mary B. Macek ◽  
Barry D. Shur
Keyword(s):  
Sperm Surface ◽  
Galactosyl Transferase ◽  
Egg Coat

Sperm from beta 1,4-galactosyltransferase-null mice are refractory to ZP3-induced acrosome reactions and penetrate the zona pellucida poorly

Development ◽  
1997 ◽  
Vol 124 (20) ◽  
pp. 4121-4131 ◽  
Author(s):  
Q. Lu ◽  
B.D. Shur
Keyword(s):  
Acrosome Reaction ◽  
Direct Evidence ◽  
Calcium Ionophore ◽  
Wild Type ◽  
Sperm Surface ◽  
Gamete Recognition ◽  
Dependent Signal ◽  
Relative Inability ◽  
Egg Coat

A variety of sperm surface components have been suggested to mediate gamete recognition by binding to glycoside ligands on the egg coat glycoprotein ZP3. The function of each of these candidate receptors is based upon varying degrees of circumstantial and direct evidence; however, the effects on fertilization of targeted mutations in any of these candidate receptors have not yet been reported. In this paper, we describe the effects of targeted mutations in beta1,4-galactosyltransferase, the best studied of the candidate receptors for ZP3. Surprisingly, galactosyltransferase-null (gt[−/−]) males are fertile; however, sperm from gt(−/−) males bind less radiolabeled ZP3 than wild-type sperm, and are unable to undergo the acrosome reaction in response to either ZP3 or anti-galactosyltransferase antibodies, as do wild-type sperm. In contrast, gt(−/−) sperm undergo the acrosome reaction normally in response to calcium ionophore, which bypasses the requirement for ZP3 binding. The inability of gt(−/−) sperm to undergo a ZP3-induced acrosome reaction renders them physiologically inferior to wild-type sperm, as assayed by their relative inability to penetrate the egg coat and fertilize the oocyte in vitro. Thus, although ZP3 binding and subsequent induction of the acrosome reaction are dispensable for fertilization, they impart a physiological advantage to the fertilizing sperm. A second strain of mice was created that is characterized by a loss of of the long galactosyltransferase isoform responsible for ZP3-dependent signal transduction, but which maintains normal levels of Golgi galactosylation. Sperm from these mice show that the defective sperm-egg interactions in gt(−/−) mice are due directly to a loss of the long galactosyltransferase isoform from the sperm surface and are independent of the state of intracellular galactosylation during spermatogenesis.

Boar Acrosin Digestion of the Porcine Egg Coat, Zona Pellucida, and Rearrangement of the Zona Proteins

1989 ◽  
Vol 105 (1) ◽  
pp. 138-142 ◽  
Author(s):  
Minoru Nakano ◽  
Yoko Tanaka ◽  
Tokutaro Kimura ◽  
Yumiko Hatanak ◽  
Tohru Tobita
Keyword(s):  
Zona Pellucida ◽  
Egg Coat

The Activity of Ubiquitin Activating Enzyme UBA1 Is Required for Sperm Capacitation, Acrosomal Exocytosis, and Sperm-Egg Coat Penetration During Porcine Fertilization.

2010 ◽  
Vol 83 (Suppl_1) ◽  
pp. 555-555
Author(s):  
Young-Joo Yi ◽  
Shawn W. Zimmerman ◽  
Gaurishankar Manandhar ◽  
John F. Odhiambo ◽  
Vera Jonakova ◽  
...  
Keyword(s):  
Sperm Capacitation ◽  
Acrosomal Exocytosis ◽  
Egg Coat

Comparative spermatology of 11 species of Polyplacophora (Mollusca) from the suborders Lepidopleurina, Chitonina and Acanthochitonina

1988 ◽  
Vol 235 (1279) ◽  
pp. 161-177 ◽  
Keyword(s):  
Electron Microscopy ◽  
Morphological Changes ◽  
Chromatin Condensation ◽  
Nuclear Material ◽  
Taxonomic Character ◽  
Anterior Portion ◽  
Preliminary Examination ◽  
Transmission Electron ◽  
Species Specific ◽  
Egg Coat

Transmission electron microscopy of the spermatozoa and spermatogenesis of 11 species (in three suborders Chitonina, Acanthochitonina, Lepidopleurina) of chiton has shown that each species has a sperm with a unique morphology indicating that spermatozoa can be used as a taxonomic character. Although structure is species-specific, similarities between species within suborders and subfamilies can be recognized. The spermatozoa of species from the suborders Chitonina and Acanthochitonina have a head comprising nuclear material only, the anterior portion of which is in the form of a long thin (approximately 80 nm diameter) filament. In many species the centrioles and mitochondria of the mid-piece are lateral in position, the mitochondria often being sited anteriorly alongside the nucleus. By contrast, Leptochiton asellus , a member of the more ancient suborder Lepidopleurina, has a sperm with a head comprising a nucleus and an acrosome. The mid-piece is also more conven­tional in structure with a ring of five or six spherical mitochondria (sited behind the nucleus) that surround the centrioles. The presence of the acrosome in L. asellus suggests that in the more recent chitons the acro­some has been secondarily lost. It is proposed that loss of the acrosome is correlated to a modification in egg-coat thickness. A preliminary examination of the structure of the eggs of three species has shown that those of L. asellus are surrounded by a very thick chorion (14-30 μm) whereas in Acanthochitona crinitus and Dinoplax gigas there are regions of the chorion that are less than 2 μm thick. The morphological changes that occur during spermatogenesis are very similar in the Chitonina and Acanthochitonina. During spermiogenesis the nucleus elongates to develop a long anterior filament. Chro­matin condensation within the nucleus involves the formation of fibrils that become orientated along its long axis. Closely associated with the elongating nucleus is a manchette. In L . asellus a spherical proacrosomal vesicle appears in the spermatocytes. This vesicle becomes compressed as it matures and simultaneously it migrates to the presumptive anterior end of the spermatid where it invaginates and elongates. Although the pattern of chromatin condensation in the nucleus is similar to that described above, a manchette has not been observed.

Potential assays for sperm capacitation in mammals

1994 ◽  
Vol 267 (5) ◽  
pp. C1167-C1176 ◽  
Author(s):  
A. Cohen-Dayag ◽  
M. Eisenbach
Keyword(s):  
Acrosome Reaction ◽  
Proteolytic Enzymes ◽  
Operational Definition ◽  
Common Denominator ◽  
Sperm Capacitation ◽  
Sperm Penetration ◽  
The Common ◽  
Definition Of ◽  
Potential Use ◽  
Egg Coat

Sperm capacitation is an essential process in fertilization. It apparently involves a large number of processes, the common denominator of which is that they donate to sperm the potential to undergo the acrosome reaction, i.e., to release proteolytic enzymes enabling sperm penetration through the egg coat. Although the phenomenon of capacitation has been known for more than 40 years, it is far from understood, and, consequently, there is, as yet, no operational definition of it. The lack of an assay to identify capacitated spermatozoa is both the cause and the effect of this situation. Here we critically review the major changes that are thought to occur during sperm capacitation, and assess their potential use as markers for the identification of capacitated spermatozoa.

scholarly journals Egg Coat Proteins Activate Ca2+ Entry into Mouse Sperm via CATSPER Channels

2009 ◽  
Vol 96 (3) ◽  
pp. 183a-184a
Author(s):  
Jingsheng Xia ◽  
Dejian Ren
Keyword(s):  
Coat Proteins ◽  
Mouse Sperm ◽  
Egg Coat
Sign in / Sign up

Export Citation Format

Share Document