<国立科博専報>トゲネズミの分類学的研究 : I。遺伝的分化 Taxonomic Study of Tokudaia (Rodentia : Muridae) : I.Genetic Differentiation
We studied twelve individuals of Ryukyu spiny rats, Tokudaia from Amamioshima Is.(T.o.osimensis). and Tokunoshima Is.(T.sp.). Each individual was examined for chromosome, serum protein, mitochondrial DNA and ribosoma1 DNA polymorphism. The karyotypes were analyzed by the G-banding staining method. The diploid chromosome number of Tokudaia obtained from Amamioshima and Tokunoshima were 25 and 45 respectively in lung tissue culture preparation. Agarose-gel electrophoretic analysis of the serum protein was used to document relationship between two species. Totally three bands of transferrin (Tf) protein were observed on agarose ge1. Tf^a and Tf^b type were seen in T.o.osimensis and Tf^t and Tf^b type in T.sp. The serum albumin patterns of these rats were not identical. The cleavage patterns of mitocondoria1 DNA (mtDNA) from two Tokudaia species were investigated using several restriction enzymes. The sequence divergence between T.o.osimensis and T.sp. about 16.2% was estimated. Genetic differentiation of ribosomal DNA (rDNA) non-transcribed-spacer sequences was analyzed in the two species. Southern blot analysis with a mouse rDNA probe and some restriction enzymes revealed that the major restriction fragments of these Tokudaia species had a unique pattern in the spacer region. The divergence time between T.o.osimensis and T.sp. was calculated about 2∿4 million years. Based on the significant genetic divergence shown we conclude that T.sp. is a taxonomically from T.o.osimensis.
国立科学博物館専報 22, 227-234, 1989