共查询到1条相似文献,搜索用时 15 毫秒
1.
Summary We have examined the rDNA content of male and female adult flies having only one nucleolus organizer (NO), using X chromosomes carrying wild or partially deleted bobbed loci (Xbb
+/O, Xbb
+/XNO-and Xbb/O, Xbb/XNO
-).The results show that in Xbb
+/O and Xbb
+/XNO
-flies, where only somatic gene compensation is supposed to occur, the rDNA increase, although less pronounced than previously reported, is directly proportional to the number of rRNA genes initially present in the nucleolus organizer. In Xbb/O and in Xbb/XNO
-flies the rDNA increase is relatively much higher than that observed in flies carrying bb
+ instead of bb. It is suggested that this may be due to rDNA premagnification and somatic gene compensation occurring simultaneously in the former flies.On leave of absence from International Institute of Genetics and Biophysics, Naples, Italy 相似文献