Reed K M, Oakley T H, Phillips R B
Department of Biological Sciences, University of Wisconsin-Milwaukee 53201, USA.
Gene. 1997 Feb 20;186(1):7-11. doi: 10.1016/s0378-1119(96)00655-5.
The relationship between a 217-bp AluI fragment (SnAluI-33c) from lake trout (Salvelinus namaycush) which hybridizes to the nucleolar organizer regions (NORs) and the ribosomal RNA genes was examined by Southern analysis and comparative hybridization. Restriction enzymes with recognition sites mapped in the lake trout rDNA cistron were used to digest genomic DNA into fragments of predetermined size. Comparison of the hybridization pattern of SnAluI-33c with those of two rDNA-specific probes placed this fragment within the intergenic spacer region of the rDNA cistron, approximately 3 kb upstream (5') of the 18S gene. This finding is consistent with in situ hybridization experiments showing hybridization of this fragment to sites of rDNA [Reed, K.M. and Phillips, R.B., Cytogenet. Cell Genet. 70 (1995) 104-107]. Based on cross hybridization and sequence comparisons, homologous sequences are present in other salmonid species.
通过Southern分析和比较杂交，研究了来自湖红点鲑（Salvelinus namaycush）的一个217碱基对的AluI片段（SnAluI-33c）与核仁组织区（NORs）以及核糖体RNA基因之间的关系。使用在湖红点鲑rDNA顺反子中具有识别位点的限制性内切酶将基因组DNA消化成预定大小的片段。将SnAluI-33c的杂交模式与两个rDNA特异性探针的杂交模式进行比较，将该片段定位在rDNA顺反子的基因间隔区，位于18S基因上游（5'）约3 kb处。这一发现与原位杂交实验结果一致，该实验表明该片段与rDNA位点杂交[Reed, K.M.和Phillips, R.B., Cytogenet. Cell Genet. 70 (1995) 104-107]。基于交叉杂交和序列比较，在其他鲑科物种中也存在同源序列。
