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

A molecular cytogenetic study of Gobius niger has been conducted by treating its mitotic chromosomes with silver-, CMA3- and DAPI-staining and fluorescent in situ hybridization using four multicopy or repetitive DNAs (the 28S and 5S rDNAs, the TTAGGG telomeric repeat and the mariner-like elements) as probes. In particular, the study proved the presence of NOR heteromorphism and suggested the possible role of the transposable element mariner in its genesis. In situ hybridization with the 5S rDNA probe proved the presence 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 signals were noticed.