University of Cincinnati, 614 Rieveschl Hall, Cincinnati, OH 45220, USA.
Globe Institute, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark.
Mol Phylogenet Evol. 2021 Jan;154:107001. doi: 10.1016/j.ympev.2020.107001. Epub 2020 Oct 29.
Giant sengis, or elephant-shrews (Macroscelidea; Macroscelididae; Rhynchocyon), are small-bodied mammals found in central and eastern African forests. Studies have provided contrasting views of the extent and direction of introgression among species. We generated full mitochondrial genomes, and compiled publically available mtDNA 12S and nuclear vWF sequences from Rhynchocyon cirnei, R. petersi and R. udzungwensis that had not previously been analyzed in concert, to elucidate the phylogenetic and population-specific context of potential introgression. Our spatially and phylogenetically broad sampling across species revealed substantial, unidirectional mitochondrial introgression of the R. petersi lineage into R. cirnei reichardi and R. udzungwensis, and from R. udzungwensis into R. c. reichardi. All introgression was highly localized and found only in the eastern Udzungwa Mountains forests in Tanzania. The nuclear data showed another pattern, with R. petersi haplotypes in R. cirnei cirnei and R. c. reichardi. No individuals showed both mitochondrial and nuclear introgression. Our results suggest higher levels of hybridization among giant sengi species than previously recognized, but also highlight the need for further genome-wide analysis and increased spatial sampling to clarify the many aspects of diversification and introgression in this group.
巨食蚁兽，又称象鼩（Macroscelidea；Macroscelididae；Rhynchocyon），是一种小型哺乳动物，分布于中非和东非的森林中。研究结果对物种间基因渗透的范围和方向提供了不同的观点。我们生成了完整的线粒体基因组，并编译了先前未协同分析过的 Rhynchocyon cirnei、R. petersi 和 R. udzungwensis 的公共 mtDNA 12S 和核 vWF 序列，以阐明潜在基因渗透的系统发育和种群特异性背景。我们在物种间进行了广泛的空间和系统发育采样，结果表明 R. petersi 谱系的大量单向线粒体基因渗透到了 R. cirnei reichardi 和 R. udzungwensis 中，以及从 R. udzungwensis 到 R. c. reichardi。所有的基因渗透都高度集中，只在坦桑尼亚的乌宗瓦山脉东部森林中发现。核数据显示了另一种模式，即 R. petersi 单倍型出现在 R. cirnei cirnei 和 R. c. reichardi 中。没有个体同时表现出线粒体和核基因渗透。我们的结果表明，巨食蚁兽物种间的杂交水平高于先前的认识，但也突出了需要进行进一步的全基因组分析和增加空间采样，以澄清该群体中多样化和基因渗透的许多方面。
