Russell R David, Beckenbach Andrew T
Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6.
J Mol Evol. 2008 Dec;67(6):682-95. doi: 10.1007/s00239-008-9179-0.
A +1 frameshift insertion has been documented in the mitochondrial gene nad3 in some birds and reptiles. By sequencing polyadenylated mRNA of the chicken (Gallus gallus), we have shown that the extra nucleotide is transcribed and is present in mature mRNA. Evidence from other animal mitochondrial genomes has led us to hypothesize that certain mitochondrial translation systems have the ability to tolerate frameshift insertions using programmed translational frameshifting. To investigate this, we sequenced the mitochondrial genome of the red-eared slider turtle (Trachemys scripta), where both the widespread nad3 frameshift insertion and a novel site in nad4l were found. Sequencing the region surrounding the insertion in nad3 in a number of other turtles and tortoises reveal general mitochondrial +1 programmed frameshift site features as well as the apparent redefinition of a stop codon in Parker's snake-neck turtle (Chelodina parkeri), the first known example of this in vertebrate mitochondria.
在一些鸟类和爬行动物的线粒体基因nad3中已记录到+1移码插入。通过对鸡（原鸡）的聚腺苷酸化mRNA进行测序，我们发现额外的核苷酸被转录并存在于成熟mRNA中。来自其他动物线粒体基因组的证据使我们推测，某些线粒体翻译系统能够利用程序性翻译移码来容忍移码插入。为了对此进行研究，我们对红耳龟（滑龟）的线粒体基因组进行了测序，在该基因组中发现了广泛存在的nad3移码插入以及nad4l中的一个新位点。对其他一些龟类动物nad3中插入位点周围区域进行测序，揭示了线粒体+1程序性移码位点的一般特征，以及帕克蛇颈龟（Chelodina parkeri）中一个终止密码子的明显重新定义，这是脊椎动物线粒体中已知的首个此类例子。
