School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa.
South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa.
Genome Biol Evol. 2023 Oct 6;15(10). doi: 10.1093/gbe/evad182.
A complete and high-quality reference genome has become a fundamental tool for the study of functional, comparative, and evolutionary genomics. However, efforts to produce high-quality genomes for African taxa are lagging given the limited access to sufficient resources and technologies. The southern African dwarf chameleons (Bradypodion) are a relatively young lineage, with a large body of evidence demonstrating the highly adaptive capacity of these lizards. Bradypodion are known for their habitat specialization, with evidence of convergent phenotypes across the phylogeny. However, the underlying genetic architecture of these phenotypes remains unknown for Bradypodion, and without adequate genomic resources, many evolutionary questions cannot be answered. We present de novo assembled whole genomes for Bradypodion pumilum and Bradypodion ventrale, using Pacific Biosciences long-read sequencing data. BUSCO analysis revealed that 96.36% of single copy orthologs were present in the B. pumilum genome and 94% in B. ventrale. Moreover, these genomes boast scaffold N50 of 389.6 and 374.9 Mb, respectively. Based on a whole genome alignment of both Bradypodion genomes, B. pumilum is highly syntenic with B. ventrale. Furthermore, Bradypodion is also syntenic with Anolis lizards, despite the divergence between these lineages estimated to be nearly 170 Ma. Coalescent analysis of the genomic data also suggests that historical changes in effective population size for these species correspond to notable shifts in the southern African environment. These high-quality Bradypodion genome assemblies will support future research on the evolutionary history, diversification, and genetic underpinnings of adaptation in Bradypodion.
完整且高质量的参考基因组已成为研究功能、比较和进化基因组学的基本工具。然而,由于获取充足资源和技术的机会有限,为非洲分类单元生成高质量基因组的工作进展缓慢。南非侏儒变色龙(Bradypodion)是一个相对年轻的谱系,大量证据表明这些蜥蜴具有高度的适应能力。Bradypodion 以其栖息地特化为特征,在系统发育上具有趋同表型的证据。然而,这些表型的潜在遗传结构对 Bradypodion 来说仍然未知,如果没有足够的基因组资源,许多进化问题就无法得到解答。我们使用 Pacific Biosciences 长读测序数据,为 Bradypodion pumilum 和 Bradypodion ventrale 从头组装了全基因组。BUSCO 分析表明,B. pumilum 基因组中存在 96.36%的单拷贝直系同源物,B. ventrale 中存在 94%。此外,这两个基因组的支架 N50 分别为 389.6 和 374.9 Mb。基于对这两个 Bradypodion 基因组的全基因组比对,B. pumilum 与 B. ventrale 高度同线性。此外,尽管这两个谱系的分化估计已有近 1.7 亿年,但 Bradypodion 与 Anolis 蜥蜴也是同线性的。基因组数据的合并分析还表明,这些物种有效种群大小的历史变化与南非环境的显著变化相对应。这些高质量的 Bradypodion 基因组组装将支持未来对 Bradypodion 的进化历史、多样化和适应遗传基础的研究。