Analysis of the micronuclear B type surface protein gene in Paramecium tetraurelia.
Analysis of the micronuclear B type surface protein gene in Paramecium tetraurelia.
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四尿草履虫微核B型表面蛋白基因分析
DOI：
10.1093/nar/22.23.5079
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发表时间：
1994
影响因子：
14.9
通讯作者：
Forney,J
中科院分区：
文献类型：
--
作者：
Scott,J;Leeck,C;Forney,J
草履虫的微核 DNA 包含在大核（体细胞）基因组形成过程中被精确切除的序列。在本文中，我们证明了 B 表面蛋白基因的微核拷贝中或附近存在 4 个大小从 28 到 416 个碱基对不等的被消除序列。每个切除的序列均以二核苷酸 5'TdA-3' 为界。将微核B基因与先前确定的A表面蛋白基因的微核序列进行比较表明，虽然两个基因中至少三个被消除的序列的位置是保守的，但这些序列是高度分歧的。用微核 B 基因片段转化营养大核会导致 DNA 的复制和维持，但微核特定序列不会被去除。此前的研究表明，B基因正确掺入新大核需要旧大核中存在大核B基因的拷贝。通过大核转化，我们证明微核 B 基因可以替代大核 B 基因在 DNA 加工中的作用。这表明大核 DNA 并不能指导微核特定序列的切除
The micronuclear DNA of Paramecium contains sequence that are precisely excised during the formation of the macronuclear (somatic) genome. In this paper we show that four eliminated sequences ranging in size from 28 to 416 base pairs, are present in or near the micronuclear copy of the B surface protein gene. Each excised sequence is bounded by the dinucleotide 5′TdA-3′. Comparison of the micronuclear B gene with the previously determined micronuclear sequence of the A surface protein gene shows that although the positions of at least three of the eliminated sequences are conserved in both genes, the sequences are highly divergent. Transformation of vegetative macronuclei with fragments of the micronuclear B gene results in replication and maintenance of the DNA but the micronuclear specific sequences are not removed. PRevious studies have shown that the correct incorporation of the B gene into the new marconucleus requires copies of the macronuclear B gene in the old macronucleus. Using macronuclear transformation, we show that the micronuclear B gene can substitute for the macronuclear B gene with regard to its role in DNA processing. This suggests that the macronuclear DNA is not acting as a guide for the excision of the micronuclear specific sequences