Using Giemsa staining, C-banding and Ag-NOR staining techniques, we analyzed chromosomes in adult male and female Hynobius quelpaertensis and in embryos of this species in egg sacs collected from eight localities of Cheju Island, South Korea. Chromosome pair 21 was consistently homomorphic in male specimens, while it was heteromorphic in female specimens, suggesting the occurrence of ZZ/ZW sex chromosome constitution in this species. The W chromosome, being much larger than the Z chromosome, was of three morphologically distinct types: WA, WB and WC. Lampbrush chromosomes examined in the oocytes of one female specimen having the WA chromosome showed that the short arm of the WA chromosome and the long arm of the Z chromosome paired closely and hence are genetically homologous. We also tried to analyze the structural relationship among the three types of W chromosomes based on their C-banding and Ag-NOR patterns.

maussi (leaf litter frog) 330 Eulemur fulvis 85

Initial analysis of Pseudohynobius flavomaculatus chromosomes determined the chromosome number of this species to be 2n = 52. A re-examination of Ranodon shihi chromosomes detected 2n = 66 chromosomes, in contrast with a previous finding of 2n = 64. The C-banding patterns of these two species and that ofBatrachuperus pinchonii were compared with each other. Regions of homoeology in the C-banding pattern among these three species represented 33.51–48.30% of the total length of their chromosomes. We also detected two types of chromosome rearrangement in hynobiid species based on the results of the present and previous cytogenetic studies.

We have studied karyotypes of ten pond-type Hynobius collected from 51 localities: H. leechii from Korea, and H. tsuensis, H. dunni, H. nebulosus, H. abei, H. tokyoensis, H. takedai, H. lichenatus, H. nigrescens and H. retardatus from Japan. C-banding analyses have been performed on the specimens from 38 out of the 51 localities. Among the karyological variations observed, chromosome 10 showed intra- and interspecific variations in many species, which we considered suitable for phylogenetic analysis. Our phylogenetic inferences concerning the morphological variation of chromosome 10 in ten pond-type Hynobius are summarized as follows: 1) similarity in the morphology and the amount of heterochromatin of chromosome 10 in species found in close geographic proximity to each other indicates a close phylogenetic relationship; 2) species distributed in widely separated geographic areas and yet with similar amounts of heterochromatin on chromosome 10 have conserved this chromosomal pattern from a common ancestor; 3) the main evolutionary changes of chromosome 10 are decreases in the C-positive region and transformation of the biarmed type of this chromosome to the uniarmed type by a pericentric inversion involving the C-positive region.