The Research on the Karyotypes of Six Species in the Genus Eremias from China
六种麻蜥核型的研究 The Research on the Karyotypes of Six Species in the Genus Eremias from China

Based on the Giemsa-dyeing karyotypes and silver-staining bands of 15 populations from different localities in China belonging to 6 species of the genus Eremias , We found all species studied have 19 pairs of chromosomes, the size of chromosomes reduces gradually and there are no marked differences between the arranged pairs of macrochromosomes except the last pair of microchromosome. There are the same karyotype formula as 2n=38=36I+2m with NF=38 in E. argus, E. multiocellata, E. velox, E. arguta and E. grammica; but the karyotype formula of E. vermiculata is different as 2n=38=12V+2sI+22I+2m with NF=50. The NOR are all located on one small pair in female of E. velox, and E. arguta , in male of E. grammica and E. vermiculata ,and in both male and female of E. multiocellata. We have not found two or more than two pairs of NOR. Having one pair of NOR may be common in Genus Eremias and also the trait of Eremias. We speculate that the derivation of the karyotype of E. vermiculata had two possible way: one experienced the stage of triploid, and later the Robertsonian transposal of chromosomes; the other way was through the inversions between the arms on the chromosome and the phenomenon of inversions might occur during or subsequently after the upheaval of the Tibet and Qinghai plateau and the founding of the Tianshan . With regard to the trend of the evolution of chromosomes in the lizards (1]), the karyotype of E. vermiculata is more advanced. Making specialties of E. vermiculata will help in building the phylogenic tree of Eremias. In both male and female of the species studied, the heteromorphic sex-chromosomes were not found.