Comparative cytogenetic analysis of fishes in the genus Trichopodus (Osphronemidae) in Thailand

Abstract

Abstract. Supiwong W, Wongchantra P, Thongnetr W, Mingkwan B, Chaiyasan P, Pinmongkhonkul S, Pinthong K, Tanomtong A. 2021. Comparative cytogenetic analysis of fishes in the genus Trichopodus (Osphronemidae) in Thailand. Biodiversitas 22: 3029-3036. Comparative cytogenetic study of four species of the genus Trichopodus including T. leerii, T. microlepis, T. pectoralis, and T. trichopterus from Thailand, was carried out. The specimens were collected from the Basins throughout Thailand. Chromosome preparation was directly performed from the kidney tissues. Conventional staining by Giemsa solution, Ag–NOR banding by silver nitrate solution and C-banding by NaOH solution were conducted to stain the chromosomes. Results showed that four species studied have the same diploid number and fundamental number as 46 composing of all telocentric chromosomes. Karyotypes consisting of large-medium-small sizes in T. leerii, T. microlepis, T. pectoralis and T. trichopterus were 16–28–2, 14–32–0, 20–26–0 and 10–30–6 chromosomes, respectively. The marker chromosomes which present the NOR positions are the single pair in all species but there are differences in the locations and pairs such as pairs no. 1, 7, 2 and 1, respectively. Most species except T. trichopterus, NOR sites locate at interstitial region adjacent to the centromere. T. trichopterus had the telomeric NORs. Constitutive heterochromatin blocks displayed at the centromeric/pericentromeric regions of all chromosomes in T. leerii and T. microlepis whereas in T. pectoralis and T. trichopterus, those presented at not only centromeres of several chromosome pairs, but they also were found at interstitial sites. The obtained finding, cytogenetic data has species-specific. Thus, it can be used for further study on taxonomy. Moreover, this data shows the close relationship of genetics among these species so that the application for breeding may be used in the future.

Rapid Changes in Chromosome Counts in Fishes from the Spiral Egg Clade within the Gourami Family (Osphronemidae)

“…Ag-NOR staining, c-banding, FISH, etc.) as has been done in other species in the family Osphronemidae ( Grazyna et al 2008; Pazza et al 2009; Chaiyasan et al 2021; Supiwong et al 2021 ), and measuring genome size of our study species would allow testing for non-conservative mechanisms of chromosome evolution. To test the influence of meiotic drive, work could be done to examine kinetochore protein levels during meiosis (Chmátal et al 2014), as well as the amount of minor satellite DNA repeats on the centromere, which have been associated with the action of meiotic drive in the western house mouse (Iwata-Otsubo et al 2017; Dudka and Lampson 2022).…”