scholarly journals Fertilization-Induced Activation of Phospholipase C in the Sea Urchin Egg

1999 ◽  
Vol 215 (2) ◽  
pp. 147-154 ◽  
Author(s):  
Brenda J. Rongish ◽  
Wenjun Wu ◽  
William H. Kinsey
Keyword(s):  
Phospholipase C ◽  
Sea Urchin ◽  
Sea Urchin Egg

scholarly journals Different Ca2+-releasing abilities of sperm extracts compared with tissue extracts and phospholipase C isoforms in sea urchin egg homogenate and mouse eggs

2000 ◽  
Vol 346 (3) ◽  
pp. 743-749 ◽  
Author(s):  
Keith T. JONES ◽  
Miho MATSUDA ◽  
John PARRINGTON ◽  
Matilda KATAN ◽  
Karl SWANN
Keyword(s):  
Phospholipase C ◽  
Sea Urchin ◽  
Tissue Extracts ◽  
Sea Urchin Egg ◽  
Boar Sperm ◽  
Specific Activities ◽  
Mammalian Eggs ◽  
Mouse Eggs

A soluble phospholipase C (PLC) from boar sperm generates InsP3 and hence causes Ca2+ release when added to sea urchin egg homogenate. This PLC activity is associated with the ability of sperm extracts to cause Ca2+ oscillations in mammalian eggs following fractionation. A sperm PLC may, therefore, be responsible for causing the observed Ca2+ oscillations at fertilization. In the present study we have further characterized this boar sperm PLC activity using sea urchin egg homogenate. Consistent with a sperm PLC acting on egg PtdIns(4,5)P2, the ability of sperm extracts to release Ca2+ was blocked by preincubation with the PLC inhibitor U73122 or by the addition of neomycin to the homogenate. The Ca2+-releasing activity was also detectable in sperm from other species and in whole testis extracts. However, activity was not observed in extracts from other tissues. Moreover recombinant PLCβ1, -γ1, -γ2, -∆1, all of which had higher specific activities than boar sperm extracts, were not able to release Ca2+ in the sea urchin egg homogenate. In addition these PLCs were not able to cause Ca2+ oscillations following microinjection into mouse eggs. These results imply that the sperm PLC possesses distinct properties that allow it to hydrolyse PtdIns(4,5)P2 in eggs.

scholarly journals Phospholipase C isoforms in mammalian spermatozoa: potential components of the sperm factor that causes Ca2+ release in eggs

Reproduction ◽  
2002 ◽  
pp. 31-39 ◽  
Author(s):  
J Parrington ◽  
ML Jones ◽  
R Tunwell ◽  
C Devader ◽  
M Katan ◽  
...  
Keyword(s):  
Phospholipase C ◽  
Sea Urchin ◽  
Soluble Protein ◽  
Gel Filtration ◽  
Protein Factor ◽  
Sea Urchin Egg ◽  
Inositol 1,4,5 Trisphosphate ◽  
Sperm Factor ◽  
Mammalian Eggs ◽  
Mammalian Spermatozoa

Injection of a soluble protein factor from mammalian spermatozoa triggers Ca2+ oscillations in mammalian eggs similar to those seen at fertilization. This sperm factor also generates inositol 1,4,5-trisphosphate and causes Ca2+ release in sea urchin egg homogenates and frog eggs. Recent studies have indicated that the sperm factor may be an inositol-specific phospholipase C (PLC) activity. This study investigated whether any of the commonly known PLC isoforms are components of the sperm factor. PLCbeta, PLCgamma and PLCdelta isoforms were shown to be present in boar sperm extracts. However, upon column fractionation of sperm extracts, none of the PLC isoforms detected correlated with the ability to cause Ca2+ release in eggs. In addition to our previous work on recombinant PLCs, it was also shown that PLCdelta3, PLCdelta4 and its splice variant PLCdelta4 Alt1 fail to cause Ca2+ release. The recently discovered 255 kDa PLCepsilon isoform also appears unlikely to be a component of the sperm factor, as fractionation of sperm extracts on a gel filtration column demonstrated that the peak of Ca2+-releasing activity was associated with fractions of 30-70 kDa. These findings indicate that the sperm factor that triggers Ca2+ release in eggs does not appear to have a known PLC isoform as one of its components.

scholarly journals Different Ca2+-releasing abilities of sperm extracts compared with tissue extracts and phospholipase C isoforms in sea urchin egg homogenate and mouse eggs

2000 ◽  
Vol 346 (3) ◽  
pp. 743 ◽  
Author(s):  
Keith T. JONES ◽  
Miho MATSUDA ◽  
John PARRINGTON ◽  
Matilda KATAN ◽  
Karl SWANN
Keyword(s):  
Phospholipase C ◽  
Sea Urchin ◽  
Tissue Extracts ◽  
Sea Urchin Egg ◽  
Mouse Eggs

ACID-SOLUBLE NUCLEOTIDES IN THE SEA URCHIN EGG

Embryologia ◽  
1966 ◽  
Vol 9 (3) ◽  
pp. 170-183 ◽  
Author(s):  
TOMIO YANAGISAWA ◽  
NAOHIDE ISONO
Keyword(s):  
Sea Urchin ◽  
Sea Urchin Egg
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