Comparative Cytogenetics Analysis of Chlamys farreri, Patinopecten yessoensis, and Argopecten irradians with C(0)t-1 DNA by Fluorescence In Situ Hybridization

The chromosomes of Chlamys farreri, Patinopecten yessoensis, and Argopecten irradians were studied by FISH using C. farreri C(0)t-1 DNA probes. The results showed that C(0)t-1 DNA signals spread on all chromosomes in the three scallops, whereas signal density and intensity were different strikingly. Clustering brighter signals presented in the centromeric and telomeric regions of most C. farreri chromosomes, and in the centromeric or pericentromeric regions of several P. yessoensis chromosomes. Comparative analysis of the mapping indicated a relatively higher homology in the repetitive DNA sequences of the genome between C. farreri and P. yessoensis than that between C. farreri and A. irradians. In addition, FISH showed that the distribution of C(0)t-1 DNA clustering signals in C. farreri displayed completely similar signal bands between homologous chromosomes. Based on the C(0)t-1 DNA fluorescent bands, a more exact karyotype of C. farreri has been obtained. In this study, the comparative analysis based on C(0)t-1 DNA provides a new insight into the chromosomal reconstructions during the evolution process, and it is helpful for understanding an important source of genomic diversity, species relationships, and genome evolution.