Molecular and cytogenetic analysis of the goby Gobius niger (Teleostei, Gobiidae)

A molecular cytogenetic study of Gobius niger has been conducted by treatin g its mitotic chromosomes with silver-, CMA(3)- and DAPI-staining and fluor escent in situ hybridization using four multicopy or repetitive DNAs (the 2 8S and 5S rDNAs, the TTAGGG telomeric repeat and the mariner-like elements) as probes. In particular, the study proved the presence of NOR heteromorph ism and suggested the possible role of the transposable element mariner in its genesis. In situ hybridization with the 5S rDNA probe proved the presen ce of just one 5S-bringing chromosome pair, whereas hybridization with the telomeric repeat revealed small bright hybridization spots, uniform in size and intensity, on each telomere of all chromosomes but no interstitial sig nals were noticed.