Chromosome study of Lithobius forficatus (Lithobiomorpha, Chilopoda).

The diploid number 2n = 46 and the chromosome arm number NF = 74 are described in Lithobius forficatus from Olsztyn (Poland). Analyses of silver and CMA3-stained mitotic chromosomes suggest that a single chromosome pair has active NORs which correspond to G-C-rich (CMA3-positive) chromatin. Heteromorphism of the largest metacentric chromosome pair was observed.

Chromosomal characteristics of rDNA in European grayling Thymallus thymallus (Salmonidae).

The chromosomal characteristics, locations and variations of two classes of ribosomal DNA (5S and 18S) were studied in European grayling karyotype (Thymallus thymallus, Salmonidae). Major rDNA sites as revealed by sequential CMA3/Ag staining and confirmed by in situ hybridization with a 18S rDNA probe were situated in two loci and were found to be polymorphic in size and displaying several distinct forms. The 5S rDNA was located by PRINS on three pairs of subtelocentric chromosomes, additional minor signal was present at the centromere of one metacentric element.

Localization of 5S rRNA loci in three coregonid species (Salmonidae).

In the present study the chromosome distribution of the 5S rDNA loci and its relation to the major rDNA genes were investigated in three Coregonid species (Salmonidae): Coregonus lavaretus, Coregonus peled and Coregonus albula, a family which has experienced large karyotype rearrangements along its evolution starting from a tetraploid ancestor. 5S PRINS/CMA3 sequential staining together with previous data enabled us to locate 5S rRNA genes and nucleolar organizer regions (NORs) in the three species analyzed. PRINS revealed the 5S rDNA cluster at the distal part of the long arm of a similar submetacentric chromosome pair in the three species.

Ribosomal genes in Coregonid fishes (Coregonus lavaretus, C. albula and C. peled) (Salmonidae): single and multiple nucleolus organizer regions.

Major rDNA loci, i.e. nucleolus-organizing regions (NORs), were assigned using chromomycin-A3 (CMA3) staining followed by sequential silver (Ag) staining and in situ hybridization (ISH) with a rDNA probe to the chromosomes of the European whitefish (Coregonus lavaretus), the peled (Coregonus peled) and the vendace (Coregonus albula), three closely related coregonine salmonid fishes.

Standard karyotype of sea trout (Salmo trutta morpha trutta) based on replication banding patterns.

Replication banding patterns have been obtained from in vivo treatment of Salmo trutta morpha trutta chromosomes using a modification of the 5-BrdU technique and in kidney cultures using the fluorochrome photolysis Giemsa (FPG) staining method. Each chromosome pair was identified in the karyotype based on the banding pattern, chromosome size, and centromere position. The standard karyotype of sea trout has been proposed.