Cytogenetics of Black-bearded Tomb bat (Taphozous melanopogon) by Conventional staining, Ag-NOR staining and Fluorescence in situ hybridization Techniques

Abstract

Black-bearded Tomb bat is classified as the genus of Taphozous and has a very similar morphology. The knowledge can provide cytogenetic information potentially useful to support on taxonomic classification. Five males and six females were collected from Mahasarakam province and Khon Kaen university, Khon Kaen province. The 20% Giemsa’s and 50% silver nitrate solution, respectively were applied to stain the chromosomes. Chromosomes were prepared from bone marrow tissue. The chromosomes harvesting was investigated by hypotonic-fixation-air drying technique. Giemsa’s staining, Ag-NOR staining and fluorescence in situ hybridization (FISH) staining techniques, as well as microsatellites (GC)₁₅ and (CGG)₁₀ as probes were applied. The karyotype, idiogram, position of NORs and microsatellites were performed in the present study. The results show that the diploid chromosomes number was 2n = 42 and the fundamental number (NF) were 74 chromosomes in both female and male of T. melanopogon. The autosomes consisting of 8 large metacentric, 8 medium metacentric, 2 medium submetacentric, 2 medium acrocentric, 2 small metacentric, 4 small submetacentric, 4 small acrocentric and 10 small telocentric chromosomes. The sex determination is XY, X chromosome is medium metacentric chromosomes and Y chromosome is small submetacentric chromosomes. NOR sites appeared to telomere of the short arm of the chromosome pairs 15 small acrocentric type and chromosome pairs 20 small telocentric type. The pattern of both microsatellite (GC)₁₅ and (CGG)₁₀ repeats were distributed throughout the genome as well as to all chromosomes. Karyotype formula described as 2n (42) = L^m₈ + M^m₈ + M^sm₂ + M^a₂ + S^m₂ + S^sm₄+ S^a₄ + S^t₁₀ + Sex Chromosome.