Enzyme patterns in two species of Xenopus and their hybrids☆

[摘要] DifferencesintheisozymepatternsofXenopuslaevisandXenopusmullerihavebeenutilizedtoexaminetheexpressionofallelesofbothspeciesinhybridanimals.MitochondrialMDHandtetrazoliumoxidasephenotypeswereexaminedduringthedevelopmentofnon-hybridembryosofeachspeciesandofreciprocalhybrids.Earlystagesofthehybridsresembletheenzymephenotypeofthematernalparent.AppearanceofpaternalenzymetakesplacejustpriortotheactivefeedingtadpolestageforbothmitochondrialMDHandoxidase.Thematernaleffectdisappearsshortlythereafterinearlyfeedingtadpoles,atwhichpointreciprocalhybridshaveidenticalisozymepatterns.Thereisnoevidenceforapredominanceofonespeciesovertheother.Examinationoffeedingtadpolesandadulttoadsindicatesthatbothlaevisandmulleriexpressionisstable.TheappearanceofpaternalmitochondrialMDHdoesnotcorrespondtothetimewhenothermitochondrialcomponentsbegintoincreaseinXenopus.MultiplebandsofMDHinbothspeciesandofoxidaseinlaevisareprobablynotduetotheaggregationofsubunitsproducedbydifferentallelesatthesamelocus.Thereisnoevidencefortheformationof“hybrid”moleculesconsistingofsubunitsofbothspecies.

[学科分类] 生物科学（综合）