摘要
大多数两栖类物种的染色体较长大,数目较少,是细胞遗传学,细胞工程学,发育生物学等研究的好材料。两栖类在进化地位上介于水生脊椎动物和陆生脊椎动物之间,因此,进行两栖类染色体的比较研究,对于探讨和认识动物的系统演化具有一定的意义。 有关无尾两栖类染色体组型的研究,国外已有不少报道(Benirschke et al.,1973;Bogart,1968;Guillemnin,1967;Haertel,1974;Schmid,1978a,1978b),国内吴政安(1978,1981;吴政安等,1980,1981)李树深等(1981)作了几种蛙的染色体组型研究。
A comparative study of the karyotypes was undertaken in six Amphibian species-Rana boulengeri Gunther, R. japonica japonica Gunther, R. guentheri Boulenger, R. adenopleura Boulenger, R. margaratae Lin and Microhyla ornata based on current technique with adult bone marrow cells. Five species of Genus Rana presented in this paper possess 26 chromosomes, including 5 pairs of large chromosomes and 8 pairs of small chromosomes, whereas the diploid chromosome number of Microhyla ornata is 24(2n =24) including 6 pairs of large chromosomes and 6 pairs of small ones. The chromosomes had been measured and arranged into 3 groups according to their size and centromere positions. The number, morphology and localization of secondary constrictions varies remarkably among these species analyzed in this paper. By comparing the chromosomes bearing secondary constriction, an attempt was made to establish the cytotaxonomic relationships. The secondary constriction shows polymorphism both within a certain species and between different species. The nucleolar organizer regions (NORs) often appear in the standard secondary constrictions, with the exception of a few NORs. The total absolute length of the chromosome complements shows slight variation among the different Rana species. It is probably due to a variable amount of heterochromatin. Comparison of the karyotypes in both sexes demonstrated no significant morphological difference, no heteromorphic pair have been detected either in males or in females.
作者
陈文元
王子淑
王喜忠
杨玉华
孙启玲
Chen Wenyuan;Wang Zisu;Wang Xizhong;Yang Yuhua;Sun Qiling(Department of Biology,University of Sichuan,Chengdu)
