Hatzoglou E, Rodakis G C, Lecanidou R
Department of Biochemistry, Cell and Molecular Biology, and Genetics, University of Athens, Greece.
Genetics. 1995 Aug;140(4):1353-66. doi: 10.1093/genetics/140.4.1353.
The complete sequence (14,130 bp) of the mitochondrial DNA (mtDNA) of the land snail Albinaria coerulea was determined. It contains 13 protein, two rRNA and 22 tRNA genes. Twenty-four of these genes are encoded by one and 13 genes by the other strand. The gene arrangement shares almost no similarities with that of two other molluscs for which the complete gene content and arrangement are known, the bivalve Mytilus edulis and the chiton Katharina tunicata; the protein and rRNA gene order is similar to that of another terrestrial gastropod, Cepaea nemoralis. Unusual features include the following: (1) the absence of lengthy noncoding regions (there are only 141 intergenic nucleotides interspersed at different gene borders, the longest intergenic sequence being 42 nucleotides) (2) the presence of several overlapping genes (mostly tRNAs), (3) the presence of tRNA-like structures and other stem and loop structures within genes. An RNA editing system acting on tRNAs must necessarily be invoked for posttranscriptional extension of the overlapping tRNAs. Due to these features, and also because of the small size of its genes (e.g., it contains the smallest rRNA genes among the known coelomates), it is one of the most compact mitochondrial genomes known to date.
测定了陆地蜗牛蓝阿扁螺线粒体DNA（mtDNA）的完整序列（14,130碱基对）。它包含13个蛋白质基因、两个rRNA基因和22个tRNA基因。其中24个基因由一条链编码，13个基因由另一条链编码。该基因排列与另外两种已知完整基因内容和排列的软体动物，即双壳贝类紫贻贝和石鳖脉红螺几乎没有相似之处；蛋白质和rRNA基因顺序与另一种陆生腹足动物果园蜗牛相似。异常特征包括：（1）不存在长的非编码区（不同基因边界处仅散布着141个基因间核苷酸，最长的基因间序列为42个核苷酸）（2）存在几个重叠基因（大多为tRNA），（3）基因内存在tRNA样结构和其他茎环结构。必须调用一个作用于tRNA的RNA编辑系统来对重叠的tRNA进行转录后延伸。由于这些特征，也因其基因尺寸小（例如，它拥有已知真体腔动物中最小的rRNA基因），它是迄今为止已知的最紧凑的线粒体基因组之一。
