Mitochondrial DNA sequences are frequently transferred into the nuclear genome, generating nuclear mitochondrial DNA sequences (NUMTs). Here, we analysed, for the first time, NUMTs in the ovine genome. We obtained 760 alignment matches covering 513.8 kbp of the sheep nuclear genome. After a merging step, we identified 390 NUMT regions with a total length of ~720 kbp, representing 0.02% of the nuclear genome. We discovered copies of all mitochondrial regions and found that most NUMT regions are intergenic or intronic. Ovine NUMTs are mostly not transcribed. However, we identified within some of the NUMTs, potential new genes encoding nuclear humanin isoforms. To rule out the possibility that the identified NUMTs could be artifacts of the Oar Rambouillet v1.0 genome assembly, we validated experimentally nine NUMT regions by PCR amplification. As we found several NUMT regions showing high similarity to the mitochondrial genome that potentially could pose a risk to ovine DNA mitochondrial studies, special care must be taken for the selection of primers for PCR amplification of mitochondrial DNA sequences.

中文翻译：

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整合到绵羊核基因组中的线粒体序列的鉴定和表征

线粒体 DNA 序列经常被转移到核基因组中，产生核线粒体 DNA 序列 (NUMTs)。在这里，我们首次分析了绵羊基因组中的 NUMT。我们获得了 760 个比对匹配，覆盖了绵羊核基因组的 513.8 kbp。合并步骤后，我们确定了 390 个 NUMT 区域，总长度约为 720 kbp，占核基因组的 0.02%。我们发现了所有线粒体区域的副本，并发现大多数 NUMT 区域是基因间或内含子区域。绵羊 NUMT 大多不被转录。然而，我们在一些 NUMT 中发现了编码核人类亚型的潜在新基因。排除识别出的 NUMT 可能是Oar Rambouillet v1.0 的人工制品的可能性基因组组装，我们通过 PCR 扩增实验验证了 9 个 NUMT 区域。由于我们发现几个 NUMT 区域显示出与线粒体基因组的高度相似性，可能会对绵羊 DNA 线粒体研究构成风险，因此必须特别注意选择用于线粒体 DNA 序列 PCR 扩增的引物。