D'Ambrosio E, Waitzkin S D, Witney F R, Salemme A, Furano A V
Mol Cell Biol. 1986 Feb;6(2):411-24. doi: 10.1128/mcb.6.2.411-424.1986.
We present the DNA sequence of a 6.7-kilobase member of the rat long interspersed repeated DNA family (LINE or L1Rn). This member (LINE 3) is flanked by a perfect 14-base-pair (bp) direct repeat and is a full-length, or close-to-full-length, member of this family. LINE 3 contains an approximately 100-bp A-rich right end, a number of long (greater than 400-bp) open reading frames, and a ca. 200-bp G + C-rich (ca. 60%) cluster near each terminus. Comparison of the LINE 3 sequence with the sequence of about one-half of another member, which we also present, as well as restriction enzyme analysis of the genomic copies of this family, indicates that in length and overall structure LINE 3 is quite typical of the 40,000 or so other genomic members of this family which would account for as much as 10% of the rat genome. Therefore, the rat LINE family is relatively homogeneous, which contrasts with the heterogeneous LINE families in primates and mice. Transcripts corresponding to the entire LINE sequence are abundant in the nuclear RNA of rat liver. The characteristics of the rat LINE family are discussed with respect to the possible function and evolution of this family of DNA sequences.
我们展示了大鼠长散在重复DNA家族（LINE或L1Rn）中一个6.7千碱基成员的DNA序列。该成员（LINE 3）两侧有一个完美的14碱基对（bp）直接重复序列，是这个家族的全长或接近全长成员。LINE 3包含一个约100 bp的富含A的右端、多个长（大于400 bp）的开放阅读框，以及每个末端附近一个约200 bp的富含G + C（约60%）的簇。将LINE 3序列与我们也展示的另一个成员约一半的序列进行比较，以及对该家族基因组拷贝的限制性酶切分析表明，就长度和整体结构而言，LINE 3在该家族约40000个其他基因组成员中相当典型，这些成员占大鼠基因组的比例高达10%。因此，大鼠LINE家族相对同质，这与灵长类动物和小鼠中的异质LINE家族形成对比。与整个LINE序列相对应的转录本在大鼠肝脏的核RNA中大量存在。我们讨论了大鼠LINE家族的特征，涉及该DNA序列家族可能的功能和进化。
