title: Molecular characteristics of horse phospholipase C zeta (PLCζ).
abstract: A sperm-specific phospholipase C (PLC), PLCzeta (PLCζ), is thought to underlie the initiation of calcium ([Ca(2+) ]i ) oscillations that induce egg activation in mammals. In large domestic species, only bovine, porcine and recently equine PLCζ have been cloned, and the physiological functions of these molecules have not been fully characterized. Here, we evaluated the physiological functions of equine PLCζ (ePLCζ) in mouse oocytes. ePLCζ was cloned from testis using RT-PCR. The expression of ePLCζ messenger RNA was confirmed in testis but not in other tissues. Microinjection of ePLCζ complementary RNA (cRNA) into mouse oocytes induced long-lasting [Ca(2+) ]i oscillations, and most of the injected oocytes formed pronuclei (PN). The injection of cRNAs encoding horse, mouse, human and cow PLCζ into mouse oocytes showed that ePLCζ had the highest [Ca(2+) ]i oscillation-inducing activity among the species tested. Mutation of D202R, which renders the protein inactive, abrogated the activity of ePLCζ. The nuclear translocation ability of ePLCζ was defective when expressed in mouse oocytes. Taken together, our findings show for the first time that ePLCζ has highest activity of the mammalian species studied to date. Our findings will be useful for the improvement of reproductive technologies in the horse.
authors.affiliation: Laboratory of Animal Reproduction, Graduate School of Veterinary Science, Azabu University, Sagamihara 252-5201, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Sato
authors.forename: Takuya
authors.initials: T
authors.lastname: Wakai
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Seita
authors.forename: Akiko
authors.initials: A
authors.lastname: Takizawa
authors.forename: Rafael A
authors.initials: RA
authors.lastname: Fissore
authors.forename: Junya
authors.initials: J
authors.lastname: Ito
authors.forename: Naomi
authors.initials: N
authors.lastname: Kashiwazaki
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000032:analysis; D003001:Cloning, Molecular; D005260:Female; D006736:Horses / Q000502:physiology*; D008297:Male; D051379:Mice; D008845:Microinjections; D009865:Oocytes / Q000502:physiology; D018075:RNA, Complementary; D013094:Spermatozoa / Q000166:cytology; D010738:Type C Phospholipases / Q000235:genetics / Q000502:physiology*
chemical_list: D018075:RNA, Complementary; D010738:Type C Phospholipases; D002118:Calcium