REPLICATION, C-BANDING AND FLUORESCENT CHROMOSOME-BANDING PATTERNS INEUROPEAN WHITEFISH, COREGONUS-LAVARETUS L

Thr chromosome complement of Coregonus lavaretus was investigated usin g C-banding, DAPI and CMA, fluorescent stainings, and replication band ing techniques. Diploid chromosome number was 2n = 80, and the arm num ber was NF= 100. Karyotype consisted of 8 pairs of metacentrics, 2 pai rs of submetacentrics, 2 pairs of subtelocentrics and 28 pairs of acro centrics, gradually decreasing in size, and of 0-4 supernumerary chrom osomes. Chromomycin A(3) staining revealed the location of nucleolar o rganizer regions (NORs), showing that examined fish possessed two pair s of submetacentric-subtelocentric (sin-sr) NOR-bearing chromosomes. S taining with DAPI revealed the distribution of AT-rich regions. The us e of in vivo 5-bromodeoxyuridine (BrdU) incorporation technique induce d highly reproducible replication bands. All banding patterns obtained in the study allowed identification of numerous chromosome pairs in t he Coregonus lavaretus karyotype. Chromosome 1 showed individual varia tion in the amount of C-positive heterochromatin resulting in the leng th polymorphism of this pair. Replication banding pattern in European whitefish showed differences between three Forms of the first chromoso me pair.