Genomic in situ hybridization in interspecific hybrids of scallops (Bivalvia, Pectinidae) and localization of the satellite DNA Cf303, and the vertebrate telomeric sequences (TTAGGG)n on chromosomes of scallop Chlamys farreri (Jones & Preston, 1904).

Mitotic chromosome preparations of the interspecific hybrids Chlamys farreri (Jones & Preston, 1904) × Patinopecten yessoensis (Jay, 1857), C. farreri × Argopecten irradians (Lamarck, 1819) and C. farreri × Mimachlamys nobilis (Reeve, 1852) were used to compare two different scallop genomes in a single slide. Although genomic in situ hybridization (GISH) using genomic DNA from each scallop species as probe painted mitotic chromosomes of the interspecific hybrids, the painting results were not uniform; instead it showed species-specific distribution patterns of fluorescent signals among the chromosomes. The most prominent GISH-bands were mainly located at centromeric or telomeric regions of scallop chromosomes. In order to illustrate the sequence constitution of the GISH-bands, the satellite Cf303 sequences of C. farreri and the vertebrate telomeric (TTAGGG)n sequences were used to map mitotic chromosomes of C. farreri by fluorescence in situ hybridization (FISH). The results indicated that the GISH-banding pattern presented by the chromosomes of C. farreri is mainly due to the distribution of the satellite Cf303 DNA, therefore suggesting that the GISH-banding patterns found in the other three scallops could also be the result of the chromosomal distribution of other species-specific satellite DNAs.

栉孔扇贝（Chlamys farreri，Jones & Preston，1904）×虾夷扇贝（Patinopecten yessoensis，Jay，1857）、栉孔扇贝×海湾扇贝（Argopecten irradians，Lamarck，1819）以及栉孔扇贝×华贵栉孔扇贝（Mimachlamys nobilis，Reeve，1852）的有丝分裂染色体标本被用于在同一张玻片上比较两种不同的扇贝基因组。尽管以每种扇贝的基因组DNA为探针进行的基因组原位杂交（GISH）能够对种间杂种的有丝分裂染色体进行染色，但染色结果并不均匀；相反，它在染色体之间呈现出物种特异性的荧光信号分布模式。最显著的GISH带主要位于扇贝染色体的着丝粒或端粒区域。为了阐明GISH带的序列组成，利用栉孔扇贝的Cf303卫星序列以及脊椎动物的端粒（TTAGGG）n序列通过荧光原位杂交（FISH）对栉孔扇贝的有丝分裂染色体进行定位。结果表明，栉孔扇贝染色体呈现的GISH带型主要是由于卫星Cf303 DNA的分布所致，因此推测在其他三种扇贝中发现的GISH带型也可能是其他物种特异性卫星DNA在染色体上分布的结果。