PLC zeta: a sperm-specific trigger of Ca(2+) oscillations in eggs and embryo development.
Upon fertilisation by sperm, mammalian eggs are activated by a series of intracellular Ca(2+) oscillations that are essential for embryo development. The mechanism by which sperm induces this complex signalling phenomenon is unknown. One proposal is that the sperm introduces an exclusive cytosolic factor into the egg that elicits serial Ca(2+) release. The 'sperm factor' hypothesis has not been ratified because a sperm-specific protein that generates repetitive Ca(2+) transients and egg activation has not been found. We identify a novel, sperm-specific phospholipase C, PLC zeta, that triggers Ca(2+) oscillations in mouse eggs indistinguishable from those at fertilisation. PLC zeta removal from sperm extracts abolishes Ca(2+) release in eggs. Moreover, the PLC zeta content of a single sperm was sufficient to produce Ca(2+) oscillations as well as normal embryo development to blastocyst. Our results are consistent with sperm PLC zeta as the molecular trigger for development of a fertilised egg into an embryo.
Cell Signalling Laboratory, Wales Heart Research Institute, University of Wales College of Medicine, Cardiff CF14 4XN, UK.
Christopher M
CM
Saunders
Mark G
MG
Larman
John
J
Parrington
Llewellyn J
LJ
Cox
Jillian
J
Royse
Lynda M
LM
Blayney
Karl
K
Swann
F Anthony
FA
Lai
D000595:Amino Acid Sequence; D000818:Animals; D001572:Benzofurans / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D003001:Cloning, Molecular; D005314:Embryonic and Fetal Development; D005306:Fertilization / Q000502:physiology; D005456:Fluorescent Dyes / Q000378:metabolism; D007093:Imidazoles / Q000378:metabolism; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008845:Microinjections; D008969:Molecular Sequence Data; D010063:Ovum / Q000378:metabolism*; D054801:Phosphoinositide Phospholipase C; D010802:Phylogeny; D016415:Sequence Alignment; D013094:Spermatozoa / Q000201:enzymology*; D014018:Tissue Distribution; D010738:Type C Phospholipases / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*
D001572:Benzofurans; D005456:Fluorescent Dyes; D007093:Imidazoles; D007527:Isoenzymes; C082877:fura red; D010738:Type C Phospholipases; D054801:Phosphoinositide Phospholipase C; C499234:Plcz1 protein, mouse