Karyological Characterization of the Butterfly Lizard (<i>Leiolepis reevesii rubritaeniata</i>, Agamidae, Squamata) by Molecular Cytogenetic Approach

Abstract

Karyological characterization of the butterfly lizard (Leiolepis reevesii rubritaeniata) was performed by conventional Giemsa staining, Ag-NOR banding, FISH with the 18S-28S and 5S rRNA genes and telomeric (TTAGGG)n sequences, and CGH. The karyotype was composed of 2 distinct components, macrochromosomes and microchromosomes, and the chromosomal constitution was 2n = 2x = 36 (L₄^m + L₂^sm + M₂^m + S₄^m + 24 microchromosomes). NORs and the 18S-28S rRNA genes were located at the secondary constriction of the long arm of chromosome 1, and the 5S rRNA genes were localized to the pericentromeric region of chromosome 6. Hybridization signals of (TTAGGG)n sequences were observed at the telomeric ends of all chromosomes and interstitially at the same position as the 18S-28S rRNA genes, suggesting that in the Leiolepinae tandem fusion probably occurred between chromosome 1 and a microchromosome where the 18S-28S rRNA genes were located. CGH analysis, however, failed to identify sex chromosomes, suggesting that this species may have a TSD system or exhibit GSD with morphologically undetectable cryptic sex chromosomes. Homologues of 6 chicken Z-linked genes (ACO1/IREBP, ATP5A1, CHD1, DMRT1, GHR, RPS6) were all mapped to chromosome 2p in the same order as on the snake chromosome 2p.

Cytogenetic Study of Northeastern Butterfly Lizard, <i>Leiolepis reevesii rubritaeniata</i> (Squamata, Agamidae) in Northeast Thailand

“…We found one pair of Ag-NOR sites in all of the samples examined. However, the results were similar to the previous report on L. reevesii rubritaeniata (Srikulnath et al 2009). NOR location can describe chromosome evolution.…”

“…Meanwhile, the haploid karyotype of L. boehmei differs from those of other congenetic species in possessing fewer microchromosomes (11 versus 12) (Aranyavalai et al 2004). The karyotypes are not different for the sex chromosomes of both males and females, as also seen in the karyotypes of other Leiolepis species (Shoubai et al 1987, Darevsky and Kupriyanova 1993, Aranyavalai et al 2004, Srikulnath et al 2009). …”

“…1). The haploid chromosome number and morphology of macrochromosomes were similar to those of other diploid species, L. belliana and L. guttata (Kupriyanova 1984, Shoubai et al 1987, Solleder and Schmid 1988, Schmitz et al 2001, Srikulnath et al 2009 (Table 1), and of the triploid L. triploida (Hall 1970). Meanwhile, the haploid karyotype of L. boehmei differs from those of other congenetic species in possessing fewer microchromosomes (11 versus 12) (Aranyavalai et al 2004).…”

“…, and L. guttata (2n=36) (Kupriyanova 1984, Shoubai et al 1987, Solleder andSchmid 1988, Schmitz et al 2001, Srikulnath et al 2009). Unisexual triploids have been reported for L. triploida (2n=54) and L. guentherpetersi (2n=54) (Hall 1970, Darevsky andKupriyanova 1993).…”

“…There have been few previous literature reviews about the chromosome analysis of lizards in the genus Leiolepis, as undertaken by Satrawaha and Ponkanid (1988), Darevsky and Kupriyanova (1993), Wongwattana et al (2001), Aranyavalai et al (2004) and Srikulnath et al (2009). The aim of the present study is to report the karyotype analysis and chromosomal characteristics of the nucleolar organizer regions (NORs) of L. reevesii rubritaeniata from northeast Thailand.…”