玉米mir1基因在玉米和薏苡中的比较物理定位

玉米基因mir1编码一种抗秋季黏虫的半胱氨酸蛋白酶。利用RFLP作图mir1基因被定位在玉米第 6号染色体短臂上 ,但它在第 6号染色体短臂上的物理位置还不知道。实验以mir1和 4 5SrDNA为探针 ,通过双色荧光原位杂交技术确定了mir1基因在玉米细胞分裂中期和粗线期第 6号染色体上的物理位置。Southern杂交结果表明 ,在薏苡基因组中存在mir1基因的同源序列 ,进一步利用荧光原位杂交的方法确定mir1基因的同源序列定位于薏苡第 7号染色体长臂的近末端 ,其信号与着丝粒的百分距离为 73 33± 0 15。

Comparative Physical Localization of Maize mir1 Gene in Zea mays L.and Coix lacryma-jobi L.

The maize gene mir1 encoded a cystein proteinase which is resistant to fall armyworm. Previously,RFLP map indicated that the mir1 was napped on chromosome 6. However,physical location of the mir1 gene on chromosone 6 has not been reported. In this study,the mir1 gene was physically located on the short arm of metaphase and pachytene chromosome 6 by dual-color fluorescence in situ hybridization (FISH) with 45S rDNA as a reference marker. The results of Southern blotting suggested that there were sequences homologous to mir1 in Coix lacryma-jobi L. genome. Then, the sequences were mapped on the distal region of long arm of chromosome 7 in C. lacryma-jobi by FISH. The percent distance from the signal site to centromere was 73.33 ±0.15.