STRUCTURE AND GENOMIC ORGANIZATION OF PRORETROVIRUS-LIKE ELEMENTS PARTIALLY ELIMINATED FROM THE SOMATIC GENOME OF ASCARIS-LUMBRICOIDES
STRUCTURE AND GENOMIC ORGANIZATION OF PRORETROVIRUS-LIKE ELEMENTS PARTIALLY ELIMINATED FROM THE SOMATIC GENOME OF ASCARIS-LUMBRICOIDES
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DOI：
10.1002/j.1460-2075.1986.tb04650.x
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发表时间：
1986-12-01
期刊：
影响因子：
11.4
通讯作者：
TOBLER, H
中科院分区：
文献类型：
--
作者：
AEBY, P;SPICHER, A;TOBLER, H
从消除染色质线虫蛔虫（Ascaris lumbricoides var.）的生殖系基因组文库中分离到一个含有中间重复序列的克隆。suum。通过比较不同环境中含有该元素的几个克隆，阐明了该元素的结构。其侧翼为256 bp长的末端重复序列（LTR），并具有. apprx的内部区域。7 kb。已经确定了5“和3”LTR的核苷酸序列。该元件与逆转录病毒前病毒和相关的移动的元件具有很强的结构相似性。因此，它被命名为“塔斯”，为蛔虫的转座子样元件。大约有50个Tas副本分布在. apprx上。20个不同的染色体位点它们的基因组分布在个体之间不同，表明Tas元件在蛔虫基因组中是移动的。两种变体形式，Tas-1和Tas-2，以约1/3的比例存在。2到1的基因组中，已被表征。它们不仅在限制模式上不同，而且在消除行为上也不同。虽然只有大约四分之一的Tas-1元件从体细胞谱系中排出，但所有的Tas-2拷贝都被特异性消除，因此仅限于生殖系细胞。我们已经证明，一个克隆的代表Tas-1元件被驱逐伴随着其侧翼的DNA序列在染色质消除过程中。
A clone containing a middle repetitive element next to satellite DNA has been isolated from a germ line genomic library of the chromatin eliminating nematode Ascaris lumbricoides var. suum. The structure of this element has been elucidated by comparison of several clones containing the element in different environments. It is flanked by 256-bp-long terminal repeats (LTRs) and has an internal region of .apprx. 7 kb. The nucleotide sequences of both the 5'' and the 3'' LTRs have been determined. The element has a strong structural similarity with retroviral proviruses and related mobile elements. It was therefore named ''Tas'', for transposon-like element of Ascaris. Approximately 50 Tas copies are dispersed over .apprx. 20 different chromosomal sites. Their genomic distribution varies between individuals, indicating that Tas elements are mobile in the Ascaris genome. Two variant forms, Tas-1 and Tas-2, present in a ratio of .apprx. 2 to 1 in the germ line genome, have been characterized. They differ not only in their restriction pattern, but also in their elimination behaviour. While only about one-fourth of the Tas-1 elements are expelled from the somatic cell lineage, all Tas-2 copies are specifically eliminated and are thus confined to the germ line cells. We have demonstrated that a cloned representative of Tas-1 elements is expelled concomitantly with its flanking DNA sequences during the chromatin elimination process.