Muhammet GAFFAROLU
In this study, nucleolar organizer regions of Chalcalburnus mossulensis were investigated. Analysis of karyotypes revealed that the diploid numbers of chromosomes was 2n=50. There were six pairs of metacentric, eight pairs of submetacentric, five pairs of subtelocentric and six pairs of acrocentric chromosomes in the karyotype. It was shown that C. mossulensis possessed two pairs of nucleolar organizer regions-bearing chromosomes. One nucleolar organizer region was located terminally on the longer arm of a larger sized submetacentric chromosome, whereas the other nucleolar organizer region was located terminally on the short arm of a medium sized submetacentric chromosome. There was no significant difference in chromosomal nucleolar organizer region phenotypes and in number of nucleolar organizer regions among localities. Our results were compared with previous results of other researchers.
