Acell-freesystembasedupontheeggextractsfromgynogeneticgibelcarp(Carassiusauratusgibelio)orbisexualredcommoncarp(Cyprinuscarpioredvariety)wasdevelopedtoinvestigatedevelopmentalbehaviorsofthedemembranatedspermnuclei.Bothredcommoncarpandgibelcarpspermnucleicoulddecondensefullyandformpronucleiintheredcommoncarpeggextracts.Gibelcarpspermnucleicouldalsodecondensefullyandformpronucleiinthegibelcarpeggextracts,butredcommoncarpspermnucleicouldnotdecondensesufficientlyinthesameextracts.Thesignificantdifferencesofmorphologicalchangeswerefurtherconfirmedbyultrastructuralobservationoftransmissionelectronmicroscopy.Thedatafurtheroffercytologicalevidenceforgonochoristicreproductioninthegynogeneticallyreproducinggibelcarp.Inaddition,thespermnucleiinvitrodecondensationisdependentonthepHintheextracts,andthedecon-densedefficiencyisoptimalatpH7.However,noDNAreplicationwasobservedinthetwokindsofeggextractsduringtheincubationperiodofthespermnuclei.Itissuggestedthattheeggextractspreparedfromthegynogeneticgibelcarpshouldbeavalidinvitrosystemforstudyingmolecularmechanismongynogenesisandreproductionmodepersityinfish.
