Endow S A
Genetics. 1982 Sep;102(1):91-9. doi: 10.1093/genetics/102.1.91.
The question of whether the Ybb- chromosome contains ribosomal genes has been examined by using Southern blot analysis and comparing rDNA hybridization patterns for X/X and X/Ybb- DNA. The results demonstrate that the Ybb- chromosome contains sequences that hybridize to an rDNA probe under stringent conditions. Differential hybridization of some of these sequences with DNAs corresponding to different regions of a complete ribosomal gene repeat provides evidence that some of the genes on the Ybb- chromosome are type 2 repeats. Because data obtained by other workers suggest that type 2 repeats are transcribed only to low levels, these repeats may be classed as "nonfunctional". A further finding is that the ribosomal genes on the Ybb- chromosome do not undergo multiple rounds of DNA replication during polytenization of X/Ybb- cells.
通过Southern印迹分析并比较X/X和X/Ybb- DNA的rDNA杂交模式，研究了Ybb-染色体是否含有核糖体基因的问题。结果表明，Ybb-染色体含有在严格条件下与rDNA探针杂交的序列。这些序列中的一些与完整核糖体基因重复序列不同区域对应的DNA的差异杂交提供了证据，表明Ybb-染色体上的一些基因是2型重复序列。由于其他研究人员获得的数据表明2型重复序列仅转录至低水平，这些重复序列可能被归类为“无功能的”。进一步的发现是，在X/Ybb-细胞多线化过程中，Ybb-染色体上的核糖体基因不会经历多轮DNA复制。
