engleski

Karyotype investigations in the European native crayfish

This study reports on the chromosome number and karyological characteristics of the four European native crayfish species, Austropotamobius pallipes, A. torrentium, Astacus astacus and A. leptodactylus. The karyotype of Austropotamobius pallipes consists of 2n=168 chromosomes, A. torrentium of 2n=164 chromosomes while the karyotypes of A. astacus and A. leptodactylus contain slightly higher number of chromosomes: 2n=176 and 2n=180, respectively. The karyotype formulas are 148m+18sm+2a, 148m+16sm and 104m+70sm+2a for Austropotamobius pallipes, A. torrentium and Astacus astacus, respectively. Fluorochrome staining with 4, 6-diamino-2-phenylindole (DAPI) has revealed that the majority of chromosomes in all four species are characterised by large heterochromatic blocks located in the centromeric and pericentromeric (genus Austropotamobius) or intercalary (genus Astacus) positions on the chromosomes. The karyotype differences between the four European native crayfish species suggests that chromosomal changes involving change in the chromosome number as well as amplification and transposition of repetitive DNAs played an important role in the in the evolution and speciation of these crayfish species.

Austropotamobius; Astacus; chromosome number; karyotype

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