CHROMOSOME KARYOTYPIC ANALYSIS AND Ag-NORs OF PACIFIC COD GADUS MACROCEPHALUS

Lymphocytes were collected and utilized for Ag-staining to study the karyotype of wild Pacific Cod (Gadus macrocephalus). The results showed that the diploid chromosome number of Gadus macrocephalus was 2n=46, and their karyotype was composed of four pairs of metacentric chromosome, three pairs of submetacentric chromosome, ten pairs of subtelocentric chromosome, six pairs of telocentric chromosome, and 60 chromosome arms. Thus, theThe karyotype formulae are karyotypic formulae are 2n=46=8m+6sm+20st+12t and NF=60. The quantification of Ag-NOR sites in interphase/metaphase cells demonstrated the polymorphisms from one to three. In the interphase, the frequency of two Ag-NORs was 82%, and in the metaphase, 87.1% cells had one Ag-NOR. The secondary constriction was observed in the No.12 subtelocentric chromosome, where Ag-NORs located. No Ag-NORs combination and sex related heteromorphic chromosome were found in the current study.