牛蛙Rana catesbeiana Shaw染色体组型分析

A Study of the Karyotype of Rana catesbeiana Shaw

采用骨髓细胞直接制片法分析了在福州地区养殖的牛蛙染色体组型,与在国内外其他地区所观察的比较。结果表明,牛蛙染色体为2n=26,全部染色体除第2、3、8、12四对为亚中部着丝点染色体外,其余皆为中部着丝点染色体,在第7对染色体短臂上和第10对染色体长臂上有明显的次缢痕。在第8对和第12对染色体短臂上也可见到次缢痕,但出现的频率较低,分别为7％和21％。性染色体不易辨认,这与在昆明地区养殖的牛蛙染色体基本相似,而与北美的牛蛙染色体组型在缢痕位置上有较大的差异。

The karyotype of Rana catesbeiana Shaw from o frog farm near Fuzhou was studied using the method of colchicine-hypotonic-air drying technique of the bone marrow cells.The diploid number is 26. With the exception of the 2nd 3rd, 8th and 12th chromosomes which are submetacentric, the rests are metacentric. Conspicuous secondary constrictions occur at the shorter arm of the 7th chromosome and the longer arm of the 10th chromosome. Secondary constriction also occur at the shorter arms of the 8th and 12th chromosomes in 7％ and 21％ respectively. Sex chromosomes are not conspicuous. The above findings are similar to those found in the karyotype of R. catesbeiana reared in Kunmin, China, but the positions of the secondary constrictions are different from those found in R. catesbeiana of North America.