First Cytogenetic Report of Painted Bronzeback (Dendrelaphis pictus, Colubrinae) by Giemsa’s Staining

Abstract

This study is the first cytogenetic study of painted bronzeback (Dendrelaphis pictus). Ten male and ten female snakes from Maha Sarakham province were treated by 0.03% colchicine for 18 hours. The chromosomes prepared from spleen and intestine using squash technique. Then, Hypotonic-fixation-air-drying technique was applied. The chromosomes were stained with 20% Giemsa’s solution. The karyotype showed the 2n=36 comprises 16 macrochromosomes and 20 microchromosomes. The macrochromosomes comprises 2 metacentric, 10 submetacentric and 2 telocentric chromosomes. The sex chromosome system is ZZ/ZW. The Z-chromosome is submetacentric and W-chromosome is telocentric chromosome. The secondary constrictions were found on the long arm of submetacentric chromosome pair 2. The ten pairs of microchromosomes are dot-like chromosome which cannot classify the type of chromosomes. The painted bronzeback has karyotypic formular as follows:
2n = 36 = L^m₂ + L^sm₄ + M^sm₂ + S^sm₄ + S^t₂ + ZZ/ZW + 20 microchromosomes