Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 301 Veterinary Science Building, 1971 Commonwealth Avenue, St. Paul, MN 55108, USA.
Department of Animal Science, College of Food, Agriculture, and Natural Resource Sciences, University of Minnesota, 277 Coffey Hall, 1420 Eckles Avenue, St. Paul, MN 55108, USA.
Genes (Basel). 2021 Aug 8;12(8):1223. doi: 10.3390/genes12081223.
Transposable element sequences are usually vertically inherited but have also spread across taxa via horizontal transfer. Previous investigations of ancient horizontal transfer of transposons have compared consensus sequences, but this method resists detection of recent single or low copy number transfer events. The relationship between humans and domesticated animals represents an opportunity for potential horizontal transfer due to the consistent shared proximity and exposure to parasitic insects, which have been identified as plausible transfer vectors. The relatively short period of extended human-animal contact (tens of thousands of years or less) makes horizontal transfer of transposons between them unlikely. However, the availability of high-quality reference genomes allows individual element comparisons to detect low copy number events. Using pairwise all-versus-all megablast searches of the complete suite of retrotransposons of thirteen domestic animals against human, we searched a total of 27,949,823 individual TEs. Based on manual comparisons of stringently filtered BLAST search results for evidence of vertical inheritance, no plausible instances of HTT were identified. These results indicate that significant recent HTT between humans and domesticated animals has not occurred despite the close proximity, either due to the short timescale, inhospitable recipient genomes, a failure of vector activity, or other factors.
转座元件序列通常是垂直遗传的，但也通过水平转移在分类单元之间传播。先前对转座子的古老水平转移的研究比较了共识序列，但这种方法难以检测到最近的单拷贝或低拷贝数转移事件。由于人类和驯养动物之间的持续密切接触和暴露于寄生虫，它们代表了潜在水平转移的机会，寄生虫已被确定为可能的转移载体。人类与动物之间的接触相对较短（数万年内），因此它们之间不太可能发生转座子的水平转移。然而，高质量参考基因组的可用性允许进行个体元素比较，以检测低拷贝数事件。我们使用 13 种家养动物的完整逆转录转座子套件对人类进行两两全比对 megaBLAST 搜索，总共搜索了 27,949,823 个 TEs。基于对严格过滤的 BLAST 搜索结果进行手动比较，以确定垂直遗传的证据，没有发现明显的 HTT 实例。这些结果表明，尽管人类和驯养动物之间距离很近，但由于时间尺度短、受体基因组不适宜、载体活性失败或其他因素，最近没有发生重大的 HTT。
