Mapping of mitochondrial DNA in Xenopus laevis and X. borealis: the positions of ribosomal genes and D-loops.
Mapping of mitochondrial DNA in Xenopus laevis and X. borealis: the positions of ribosomal genes and D-loops.
复制标题
非洲爪蟾和北极爪蟾线粒体 DNA 定位：核糖体基因和 D 环的位置。
DOI：
10.1016/0022-2836(78)90273-5
复制
发表时间：
1978
影响因子：
5.6
通讯作者：
I. Dawid
中科院分区：
文献类型：
--
作者：
J. Ramírez;I. Dawid
Xenopus laevisandX 中 mtDNA‡ 的序列组织。已经对borealis§进行了分析和比较。确定了几种限制性核酸内切酶的切割位点以帮助绘图研究。 laeviismtDNA以重组质粒的形式被克隆并用于一些实验。确定两个 mt-RNA 编码序列相对于彼此以及相对于限制性图谱的位置。标记复制起点的 D 环也位于该图谱上。 rRNA inX 的转录方向。 laevismtDNA 和 X 中的复制。测定了borealismtDNA。尽管一级序列有 25% 的差异以及限制性图谱的差异，rRNA 基因的位置和复制起点仍位于 X 中。莱维桑 X. borealismtDNA 非常相似。大 rRNA 基因和小 rRNA 基因彼此靠近，并间隔 120 至 160 个碱基对。转录从小到大 mt-rRNA 进行。复制起点位于远离小rRNA基因末端700至950个碱基对处，并且不对称复制远离rRNA基因进行。 mtDNA 图谱如图 10 所示。这些结果与早期对其他动物 mtDNA 的研究结果一起表明，该 DNA 分子的整体解剖结构在进化中高度保守。
The sequence organization of mtDNA‡inXenopus laevisandX. borealis§has been analyzed and compared. The cleavage sites for several restriction endonucleases were determined as an aid in mapping studies.X. laevismtDNA was cloned in the form of recombinant plasmids and used in some of the experiments. The locations of the coding sequences for the two mt-RNAs were determined relative to each other and to the restriction map. The D-loop which marks the origin of replication was also positioned on this map. The directions of transcription of rRNA inX. laevismtDNA and of replication inX. borealismtDNA were determined. Despite a 25% divergence of primary sequence and differences in restriction maps, the location of rRNA genes and the replication origin inX. laevisandX. borealismtDNA are very similar. The large and small rRNA genes are close to each other and are separated by a gap of 120 to 160 base-pairs. Transcription proceeds from the small to the large mt-rRNA. The replication origin is 700 to 950 base-pairs distal from the end of the small rRNA gene, and asymmetric replication proceeds away from the rRNA genes. The mtDNA maps are presented in Figure 10. These results together with earlier work on other animal mtDNAs show that the overall anatomy of this DNA molecule is highly conserved in evolution.