Jubier-Maurin V, Cuny G, Laurent A M, Paquereau L, Roizes G
CNRS (CRBM-UPR 8402) Inserm U.249, Institut de Biologie, Montpellier, France.
Mol Biol Evol. 1992 Jan;9(1):41-55. doi: 10.1093/oxfordjournals.molbev.a040707.
Full-length L1 elements have been shown to possess, at their 5' end, tandem repeats called "A" or "F" types. By sequencing the 5' region of two large L1 copies that did not hybridize to A or F probes, we have identified a new sequence that is found at the 5' end of many L1 elements and that we call "V." The element characterized has no 200-bp tandem repetitive structure, and the new 5' sequence is not similar to the A or F sequences. The study of the relationships between the V and L1 sequences has shown that only half of the V (i.e., V-specific 5') sequences in the genome are linked to the 5' end of L1 copies. In related rodent species, a comparative study by Southern blot and PCR analysis of the V sequence suggests that this L1 subfamily has an ancient origin and that V sequence isolated from the remainder of the L1 element has been amplified during the evolution of the mouse genome.
全长L1元件已被证明在其5'端具有称为“A”或“F”类型的串联重复序列。通过对两个与A或F探针不杂交的大型L1拷贝的5'区域进行测序，我们鉴定出一种新序列，该序列存在于许多L1元件的5'端，我们将其称为“V”。所表征的元件没有200bp的串联重复结构，并且新的5'序列与A或F序列不相似。对V和L1序列之间关系的研究表明，基因组中只有一半的V（即V特异性5'）序列与L1拷贝的5'端相连。在相关的啮齿动物物种中，通过Southern印迹和V序列的PCR分析进行的比较研究表明，这个L1亚家族起源古老，并且从小鼠基因组进化过程中L1元件其余部分分离出的V序列已经扩增。
