Conserved satellite DNA motif and lack of interstitial telomeric sites in highly rearranged African Nothobranchius killifish karyotypes

• DOI: 10.1111/jfb.15550
• Publication Date: 2023-09-04T07:40:23Z
• Authors: Karolína Lukšíková; Tomáš Pavlica; Marie Altmanová; Jana Štundlová; Šárka Pelikánová; Sergey A. Simanovsky; Eugene Yu. Krysanov; Marek Jankásek; Matyáš Hiřman; Martin Reichard; Petr Ráb; Alexandr Sember
• Keywords: Killifish

Using African annual killifishes of the genus Nothobranchius from temporary savannah pools with rapid karyotype and sex chromosome evolution, we analysed chromosomal distribution telomeric (TTAGGG)n repeat Nfu-SatC satellite DNA (satDNA; isolated furzeri) in 15 species across killifish phylogeny, Fundulosoma thierryi as an out-group. Our fluorescence situ hybridization experiments revealed that all taxa share presence but diverse organization on chromosomes. landscape was similar conspecific populations guentheri melanospilus slightly-to-moderately differed between pienaari, closely related kuhntae orthonotus. Inter-individual variability patterns found N. orthonotus krysanovi. We mostly no sex-linked studied repetitive distribution. Only brieni, possessing multiple chromosomes, occupied a substantial portion neo-Y chromosome, similarly formerly XY system turquoise furzeri its sister kadleci-representatives not to brieni. All further shared expected repeats at ends chromosomes additional interstitial sites. In summary, (i) conserved satDNA class clades (a rare pattern among ray-finned fishes); (ii) independent trajectories differentiation, recurrent convergent accumulation Y some species; (iii) genus-wide tendency loss during interchromosomal rearrangements. Collectively, our findings advance understanding genome structure, mechanisms reshuffling, differentiation perspective.