六种麻蜥核型的研究

报道麻蜥属(Eremias ,Lacertidae) 6种15个不同居群的染色体核型及银分带核型。丽斑麻蜥（E. argus）、快步麻蜥(E. velox)、敏麻蜥(E. arguta)、密点麻蜥(E. multiocellata)、网纹麻蜥（E. grammica ）的核型一致：2n=38=36I+ 2m，NF=38；虫纹麻蜥（E. vermiculata） 2n=38=12V+2sI+22I+2m, NF=50。中国麻蜥属的核型可分为3个类型：（1）丽斑麻蜥型（2）山地麻蜥(E. brenchleyi)型（3）虫纹麻蜥型。虫纹麻蜥核型演化有两种可能性（1）经历三倍体阶段，并通过罗伯逊易位形成；（2）通过染色体臂间倒位形成，倒位成因可能和天山山脉以及青藏高原的隆起有关。密点麻蜥、快步麻蜥、敏麻蜥、网纹麻蜥、虫纹麻蜥均观察到一对NOR于一对较小染色体对上。雌雄个体中均未发现性异型染色体。Abstract: 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.

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.