title: Xenopus and chicken sperm contain a cytosolic soluble protein factor which can trigger calcium oscillations in mouse eggs.
abstract: There is evidence showing that at fertilization the sperm introduces into egg cytoplasm a protein-based cytosolic factor, which serves as the physiological trigger for inducing Ca(2+) oscillations in mammalian eggs. Here we show that sperm of nonmammalian vertebrates also contain a cytosolic protein factor that can induce Ca(2+) oscillations when introduced into mammalian eggs. We have observed that cytosolic extracts derived from Xenopus or chicken sperm could induce mouse eggs to undergo Ca(2+) oscillations similar to those induced by bovine sperm extracts. The factor responsible for inducing Ca(2+) oscillations was of high molecular weight and heat- or proteinase K-labile. We show that 0.5 chicken sperm-equivalents or 1-2 Xenopus sperm-equivalents of the extracts had enough activity to trigger Ca(2+) oscillations in mouse eggs. Our findings illustrate that although Xenopus, chicken, and mammals are evolutionarily divergent species, the function of the sperm protein factor in triggering Ca(2+) oscillations in mammalian eggs appears not to be species specific in vertebrates.
authors.affiliation: Laboratory of Molecular Developmental Biology, Institute of Developmental Biology, Chinese Academy of Sciences, Beijing, 100080, People's Republic of China.
authors.forename: J B
authors.initials: JB
authors.lastname: Dong
authors.forename: T S
authors.initials: TS
authors.lastname: Tang
authors.forename: F Z
authors.initials: FZ
authors.lastname: Sun
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects; D002417:Cattle; D002645:Chickens; D005260:Female; D005306:Fertilization / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008845:Microinjections; D008970:Molecular Weight; D010063:Ovum / Q000187:drug effects / Q000378:metabolism*; D011506:Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D013045:Species Specificity; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D011506:Proteins