Standardized karyotype of the three-spot gourami, Trichogaster trichopterus (Perciformes, Belontidae) from Thailand by conventional and Ag-NOR staining technique

摘要

Standardized karyotype and idiogram of the three-spot gourami (Trichogaster trichopterus) from local market in Roi-Et province, northeast Thailand, were studied. Kidney cell samples were taken from ten male and ten female fishes. The mitotic chromosome preparations were prepared by blood cell culture as well as directly from kidney cells. Conventional and Ag-NOR staining techniques were applied to stain the chromosomes. The results showed that diploid chromosome number of T. trichopterus was 2n = 46, the fundamental numbers (NF) were 46 in both male and female. The types of autosomes were 12 large telocentric, 32 medium telocentric and 2 small telocentric chromosomes. The region adjacent to the telomere of chromosome pair 2 showed clearly observable secondary constriction / NORs. The karyotype formula for T. trichopterus could be deduced as: $ {2}nleft( {hbox{diploid}} right){46} = {hbox{L}}_{{12}}^{rm{t}} + {hbox{M}}_{{32}}^{rm{t}} + {hbox{S}}_2^{rm{t}} $ .