Cytogeneticanalysiswasperformedforthebayscallop(ArgopectenirradiansLamarck1819)andtheJapanesescallop(PatinopectenyessoensisJay1857)byprimedinsitulabeling(PRINS)andpropidiumiodide(PI)bandingtechniques.ThePRINSanalysisrevealedthatmajorrRNAgeneswereclusteredintwolocionthetelomericregionsoftheshortarmsontwoacrocentricchromosomepairsinA.irradiansandontwosubmetacentricpairsinP.yessoensis.ThehistoneH3genesitesdifferedinnumberandlocationbetweenthesetwospecies.TheC-band-likepatternsrevealedbyPIstainingvariedconsiderablybetweenthesetwospecies.A.irradiansdisplayedterminalbandsatlongarmsonallchromosomes,centromericbandsonsomepairsandinterstitialbandsonfivepairs.P.yessoensisexhibitedonlycentromericbandsonallchromosomes.TheseresultswouldcontributetothebetterunderstandingofkaryotypeevolutioninA.irradiansandP.yessoensis.
