title: Highly species-specific centromeric repetitive DNA sequences in lizards: molecular cytogenetic characterization of a novel family of satellite DNA sequences isolated from the water monitor lizard (Varanus salvator macromaculatus, Platynota).
abstract: Two novel repetitive DNA sequences, VSAREP1 and VSAREP2, were isolated from the water monitor lizard (Varanus salvator macromaculatus, Platynota) and characterized using molecular cytogenetics. The respective lengths and guanine-cytosine (GC) contents of the sequences were 190 bp and 57.5% for VSAREP1 and 185 bp and 59.7% for VSAREP2, and both elements were tandemly arrayed as satellite DNA in the genome. VSAREP1 and VSAREP2 were each located at the C-positive heterochromatin in the pericentromeric region of chromosome 2q, the centromeric region of chromosome 5, and 3 pairs of microchromosomes. This suggests that genomic compartmentalization between macro- and microchromosomes might not have occurred in the centromeric repetitive sequences of V. salvator macromaculatus. These 2 sequences did only hybridize to genomic DNA of V. salvator macromaculatus, but no signal was observed even for other squamate reptiles, including Varanus exanthematicus, which is a closely related species of V. salvator macromaculatus. These results suggest that these sequences were differentiated rapidly or were specifically amplified in the V. salvator macromaculatus genome.
authors.affiliation: the Laboratory of Animal Cytogenetics and Comparative Genomics, Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand.
authors.forename: Nampech
authors.initials: N
authors.lastname: Chaiprasertsri
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Uno
authors.forename: Surin
authors.initials: S
authors.lastname: Peyachoknagul
authors.forename: Ornjira
authors.initials: O
authors.lastname: Prakhongcheep
authors.forename: Sudarath
authors.initials: S
authors.lastname: Baicharoen
authors.forename: Saranon
authors.initials: S
authors.lastname: Charernsuk
authors.forename: Chizuko
authors.initials: C
authors.lastname: Nishida
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Matsuda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Koga
authors.forename: Kornsorn
authors.initials: K
authors.lastname: Srikulnath
mesh_terms: D000818:Animals; D001483:Base Sequence; D002503:Centromere / Q000235:genetics*; D002871:Chromosome Banding; D002875:Chromosomes; D017124:Conserved Sequence; D020732:Cytogenetic Analysis; D004276:DNA, Satellite; D059785:Karyotype; D008116:Lizards / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D004276:DNA, Satellite
keywords: Platynota; genomic compartmentalization; heterochromatin; monitor lizard; satellite DNA