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).

Liping Hu,Ke Bi,Zhenming Bao,Zujing Yang,Xiaoting Huang,Huan Liao,Liming Jiang

doi:10.3897/compcytogen.v12i1.14995

Abstract

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.

Highlights

Chromosomal bandings were used to identify chromosomes and provided insight into the substructure and organization of whole chromosomes (Rønne 1990)
The results indicated that the Genomic in situ hybridization (GISH)-banding pattern presented by the chromosomes of C. farreri is mainly due to the distribution of the satellite Cf303 DNA, suggesting that the GISH-banding patterns found in the other three scallops could be the result of the chromosomal distribution of other species-specific satellite DNAs
The hybridization signals only covered chromosomes of one parent whose genomic DNA was labeled as probes: the metaphase of C. farreri × P. yessoensis – by genomic DNA from P. yessoensis (Fig. 1D1), the metaphase of C. farreri × A. irradians – by genomic DNA from A. irradians (Fig. 1E1) and the metaphase of C. farreri × M. nobilis – by genomic DNA from M. nobilis (Fig. 1F1)

Summary

Introduction

Chromosomal bandings were used to identify chromosomes and provided insight into the substructure and organization of whole chromosomes (Rønne 1990). Some chromosome banding techniques have been applied to bivalves, e.g. C-banding was used for investigating the distribution and composition of heterochromatin (Pasantes et al 1996, Insua et al 1998, Pauls and Affonso 2000, Huang et al 2007b, García-Souto et al 2016), silver staining was used for localizing the nucleolus organizer regions (Ag-NORs) (Martínez-Expósito et al 1997, Pauls and Affonso 2000, Boroń et al 2004), fluorescence counterstaining with chromomycin A3 or DAPI/PI used to identify the GC-rich or AT-rich heterochromatic regions (Martínez et al 2002, Huang et al 2007b, Zhang et al 2007c, Pérez-García et al 2010a, García-Souto et al 2015, 2016), and fluorescent in situ hybridization (FISH) were used to localize 28S rDNA, 5S rDNA, and histone H3 gene to study karyotypic evolution on a variety of bivalves (Insua et al 1998, 2006, Wang and Guo 2004, López-Piñón et al 2005, Huang et al 2006, 2007a, Odierna et al 2006, Zhang et al 2007b, Hu et al 2011, Li et al 2016, Yang et al 2016, García-Souto et al 2015, 2016). Patterns of GISH-banding coincident with those of Giemsa C-banding were first reported in the genus Alstroemeria (Linnaeus, 1762) using standard GISH with blocking DNA (Kuipers et al 1997). Belyayev et al (2001) constructed a GISH-banding karyotype of Aegilops speltoides (Tausch, 1837) and investigated the evolutionary dynamics of repetitive sequences in Aegilops (Linnaeus, 1753). Zhou et al (2008) developed a GISH-banding protocol, built a universal reference karyotype of the Secale cereale (Linnaeus, 1753) chromosome 1R to 7R, and discriminate the repetitive sequence polymorphism in species or subspecies

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