Activation of development in mammals: is there a role for a sperm cytosolic factor?
In mammalian oocytes, fertilization-associated calcium [Ca2+]i oscillations are responsible for the activation of development. The mechanism(s) by which the sperm triggers the initial [Ca2+]i rise and supports long-lasting oscillations is not resolved. It has been proposed that the sperm may interact with receptors in the oocyte's plasma membrane and engage intracellular signaling pathways that result in Ca2+ release. A different line of investigation suggests that upon sperm-oocyte fusion, a sperm cytosolic factor is released into the oocyte which interacts with unknown cytosolic targets, and generates [Ca2+]i oscillations. We will discuss the most recent evidence for both lines of thought and demonstrate that injections of sperm crude extracts (SF) into mammalian oocytes trigger [Ca2+]i oscillations that support in vitro parthenogenetic development to the blastocyst stage.
Fissore
R A
RA
Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst 01003, USA.
Gordo
A C
AC
Wu
H
H
D000818:Animals; D002459:Cell Fusion; D003600:Cytosol / Q000502:physiology; D005260:Female; D005306:Fertilization / Q000502:physiology*; D008297:Male; D008322:Mammals; D009865:Oocytes / Q000502:physiology*; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology*