First chromosome analysis of Thai pufferfish Pao cochinchinensis (Steindachner, 1866)

Abstract

Abstract. Pissaparn M, Phimphan S, Chaiyasan P, Tanoamtong A, Liehr T, Suwannapoom C, Reungsing M, Supiwong W. 2020. First chromosome analysis of Thai pufferfish Pao cochinchinensis (Steindachner, 1866). Biodiversitas 21: 4309-4316. Here first analysis of chromosomes and nucleolar organizer region (NOR) pattern in pufferfish Pao cochinchinensis (Steindachner, 1866) was undertaken. Chromosomal preparations were obtained from kidney of P. cochinchinensis from Chi River basin in Thailand. Chromosomal characteristics were analyzed by Giemsa staining, Ag-NOR banding as well as fluorescence in situ hybridization (FISH) using microsatellites d(CA)15 and d(CGG)10 probes. P. cochinchinensis had 2n = 40 with the fundamental number (NF) 74, both in male and female. The karyotype exhibited 12 metacentric (m), 10 submetacentric (sm), 12 acrocentric (a) and 6 telocentric (t) chromosomes. No differentiated heteromorphic sex chromosomes were observed. NORs were located on short arms adjacent to telomere of the metacentric chromosome pair 4, which coincide with signals of d(CGG)10 probe. FISH with d(CGG)10 sequences were also displayed at the telomeres of most other chromosomes, whereas d(CA)15 repeats highly accumulated throughout almost all entire chromosomes except for centromeric regions. The results of conventional Giemsa staining presented the differentiation even the same genus. The localization of NORs on one pair of chromosomes only is a common characteristic found in many fish groups as well as other vertebrates. Mapping of two distinct microsatellites demonstrated the remarkable chromosomal diversification that characterizes evolution in the genus Pao. Both, conventional and molecular cytogenetics are excellent tools to study, and better understand chromosomal evolution, as well as to uncover biodiversity among fishes.

Classical and molecular cytogenetics of Belontia hasselti (Perciformes: Osphronemidae): Insights into the ZZ/ZW sex chromosome system

“…The microsatellite repeats on the chromosomes of B. hasselti showed that d(CA)15 signals are present on all chromosome pairs, throughout the whole chromosomes except for centromeric regions of some pairs (pairs 2, 4, 8, 10, 15, and sex chromosome in both sexes), whereas, in most cases, they were found along the whole chromosomes. The patterns of d(CA)15 in B. hasselti are similar to Mystus species (Supiwong et al 2013a) and Thai pufferfish Pao cochinchinensis (Pissaparn et al 2020). In turn, this pattern is inconsistent with other fish, for example, the Hoplias malabaricus Bloch 1794, d(CA)15 probe signals provided a rich banding pattern in the subtelomeric region along most chromosome arms, while d(CA)15 had only slight accumulation on the sex chromosomes (X and Y) (Cioffi et al 2011).…”

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

“…of RL and CI were calculated (Phimphan et al 2013;Pinthong et al 2017;Juntaree and Supiwong 2020). The CI (q/p) between 0.500-0.599, 0.600-0.699, 0.700-0.899, and 0.900-1.000 were described as metacentric (m), submetacentric (sm), acrocentric (a), and telocentric (t) chromosomes, respectively (Saenjundaeng et al 2018a,b;Pissaparn et al 2020;Phimphan et al 2020). The classify of chromosomal sizes, karyotyping and diagramming methods were followed by Tanomtong et al (2014), Jantarat et al (2017), andChooseangjaew et al (2017).…”