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Molecular cloning and characterization of novel centromeric repetitive DNA sequences in the blue-breasted quail (<i>Coturnix chinensis</i>, Galliformes)

2002; Karger Publishers; Volume: 98; Issue: 4 Linguagem: Inglês

10.1159/000071044

1424-8581

Kenneth M. Yamada, Mami Shibusawa, Masaoki Tsudzuki, Yoichi Matsuda,

Plant Virus Research Studies

A new family of centromeric highly repetitive DNA sequences was isolated from <i>Eco</i>RI-digested genomic DNA of the blue-breasted quail (<i>Coturnix chinensis</i>, Galliformes), and characterized by filter hybridization and chromosome in situ hybridization. The repeated elements were divided into two types by nucleotide length and chromosomal distribution; the 578-bp element predominantly localized to microchromosomes and the 1,524-bp element localized to chromosomes 1 and 2. The 578-bp element represented tandem arrays and did not hybridize to genomic DNAs of other Galliformes species, chicken <i>(Gallus gallus)</i>, Japanese quail <i>(Coturnix japonica)</i> and guinea fowl <i>(Numida meleagris)</i>. On the other hand, the 1,524-bp element was not organized in tandem arrays, and did hybridize to the genomic DNAs of three other Galliformes species, suggesting that the 1,524-bp element is highly conserved in the Galliformes. The 578-bp element was composed of basic 20-bp internal repeats, and the consensus nucleotide sequence of the internal repeats had homologies to the 41–42 bp CNM repeat and the <i>Xho</i>I family repeat of chicken. Our data suggest that the microchromosome-specific highly repetitive sequences of the blue-breasted quail and chicken were derived from a common ancestral sequence, and that they are one of the major and essential components of chromosomal heterochromatin in Galliformes species.