Cytogenetic analysis in two scallops (Bivalvia: Pectinidae) by PRINS and PI banding

Cytogenetic analysis was performed for the bay scallop (Argopecten irradians Lamarck 1819) and the Japanese scallop (Patinopecten yessoensis Jay 1857) by primed in situ labeling (PRINS) and propidium iodide (PI) banding techniques.The PRINS analysis revealed that major rRNA genes were clustered in two loci on the telomeric regions of the short arms on two acrocentric chromosome pairs in A.irradians and on two submetacentric pairs in P.yessoensis.The histone H3 gene sites differed in number and location between these two species.The C-band-like patterns revealed by PI staining varied considerably between these two species.A.irradians displayed terminal bands at long arms on all chromosomes, centromeric bands on some pairs and interstitial bands on five pairs.P.yessoensis exhibited only centromeric bands on all chromosomes.These results would contribute to the better understanding of karyotype evolution in A.irradians and P.yessoensis.