Winkfein R J, Moir R D, Krawetz S A, Blanco J, States J C, Dixon G H
Department of Medical Biochemistry, Faculty of Medicine, University of Calgary, Alberta, Canada.
Eur J Biochem. 1988 Sep 15;176(2):255-64. doi: 10.1111/j.1432-1033.1988.tb14276.x.
We have identified a new family of interspersed, moderately repetitive DNA elements, termed the RSg-1 family, in the genome of the rainbow trout. Two of the elements examined here are situated upstream of sequences which code for trout nuclear proteins; a protamine gene (p101) and the clustered histone H4 gene. Sequence comparison of various RSg-1 elements indicated a high degree of nucleotide sequence homology between different members of the family. These repetitive elements exhibit well defined 3' ends which contain poly(A) segments preceded by the consensus polyadenylation signal AATAAA. Sequences flanking the 3' end of the poly(A) tract also conform to a consensus sequence. A similar sequence is also found flanking the 5' terminus of the element in the protamine clone p101, and thus may represent a target-site duplication generated upon insertion of the element into the genome. These characteristics, together with the heterogeneous nature of the 5' ends of the elements, are reminiscent of processed pseudogenes and retroposons such as the mammalian L1 family of interspersed repetitive elements.
我们在虹鳟鱼的基因组中鉴定出了一个新的散布的、中度重复的DNA元件家族，称为RSg-1家族。这里检测的两个元件位于编码鳟鱼核蛋白的序列上游；一个鱼精蛋白基因（p101）和簇状组蛋白H4基因。对各种RSg-1元件的序列比较表明，该家族不同成员之间存在高度的核苷酸序列同源性。这些重复元件具有明确的3'末端，其中包含在共有多聚腺苷酸化信号AATAAA之前的多聚（A）片段。多聚（A）序列3'末端两侧的序列也符合共有序列。在鱼精蛋白克隆p101中，元件5'末端两侧也发现了类似的序列，因此可能代表元件插入基因组时产生的靶位点重复。这些特征，连同元件5'末端的异质性，让人联想到加工假基因和反转录转座子，如哺乳动物散布重复元件的L1家族。
