First Molecular Cytogenetics Report of Blue-headed Flying Lizard (Draco volans) outside Protected Area of Hala-bala Forest at Than To District, Yala Province, Thailand

Abstract

Background and Objectives : Variety of ecosystems in Thailand promote high biodiversity, particularly among crawling animals in the flying lizard group. Thailand harbors 10 species out of a total of 31 species of flying lizards that have been found in the world. However, there are very few studies on cellular and molecular genetics. This study aims to analyze the karyotype, chromosome type, number and distribution patterns of repeat base sequences in the chromosomes of the Blue-headed Flying Lizard (Draco volans) using fluorescence in situ hybridization technique (FISH).

Methodology : Prepare chromosomes using the direct method by injecting 0.1 milliliters of a 0.05% colchicine solution per 10 grams of body weight. Subsequently, immerse the bone marrow in potassium chloride solution (KCl) 0.075 mol/L, centrifuge, and then drop the obtained cells onto clean slides. Stain the chromosomes using conventional staining, NOR-banded, and additionally, stain using the fluorescence in situ hybridization (FISH) technique. Finally, The prepared slides were examined under compound and fluorescence microscopy.

Main Results : The karyotype of the blue-headed flying lizard reveals a diploid chromosome number of 34 and    a fundamental chromosome number of 46. Comprising of 8 pairs of large metacentric chromosomes, 2 pairs of small metacentric chromosomes, 2 pairs of large submetacentric chromosomes, and 22 pairs of small telocentric chromosomes, the karyotype of the blue-headed flying lizard displays a total of 34 chromosomes. Notably, the NOR (nucleolus organizer region) is observed on the telomeric region of the long arm of chromosome pair 1 (1q cen). Microsatellite repeat patterns indicate the presence of d(GC)₁₅, d(TA)₁₅, d(CAG)₁₀, and d(CAA)₁₀, with cumulative signals dispersed throughout the chromosomes.

Conclusions  : The diploid chromosome number of the blue-headed flying lizard is 34, consisting of 12 pairs of large chromosomes and 22 pairs of small chromosomes. The fundamental chromosome number is 46. The NOR (nucleolus organizer region) is located on of chromosome pair 1 (1q cen). The study of microsatellite repeat patterns revealed that the repeat patterns of the probe exhibited cumulative signals dispersed throughout the chromosomes. This research adds fundamental information for future studies in genetics. The blue-headed flying is karyotype formula is as follows (1).

 2n (34) =L₈^m+L₂^sm+S₂^m+Mi₂₂^dot              (1)