Chromosomes of Asian cyprinid fishes: cytogenetic analysis of two representatives of small paleotetraploid tribe Probarbini.

摘要: Polyploidy, although still poorly explored, represents an important evolutionary event in several cyprinid clades. Herein, Catlocarpio siamensis and Probarbus jullieni - representatives of the paleotetraploid tribe Probarbini, were characterized both by conventional molecular cytogenetic methods. Alike most other cyprinids (with 2n = 100), species studied here shared 2n = 98 but differed karyotypes: C. displayed 18m + 34sm + 46st/a; NF = 150, while P. exhibited 26m + 14sm + 58st/a; NF = 138. Fluorescence situ hybridization (FISH) with rDNA probes revealed two (5S) eight (18S) signals siamensis, respectively, six for jullieni. FISH microsatellite motifs evidenced substantial genomic divergence between species. The almost doubled size chromosome pairs #1 #14 compared to rest corresponding karyotypes indicated chromosomal fusions. Based on our findings, together likely same reduced remainder Probarbini species, we hypothesize that karyotype might represent a derived character, all members clade. Besides, also witnessed considerable changes amount distribution certain repetitive DNA classes, suggesting complex post-polyploidization processes this small tribe.