Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany.
Institute of Organismic and Molecular Evolution (iOME), Johannes Gutenberg University, Mainz, Germany.
Genome Biol Evol. 2019 Aug 1;11(8):2306-2311. doi: 10.1093/gbe/evz159.
The success of social insects is largely intertwined with their highly advanced chemical communication system that facilitates recognition and discrimination of species and nest-mates, recruitment, and division of labor. Hydrocarbons, which cover the cuticle of insects, not only serve as waterproofing agents but also constitute a major component of this communication system. Two cryptic Crematogaster species, which share their nest with Camponotus ants, show striking diversity in their cuticular hydrocarbon (CHC) profile. This mutualistic system therefore offers a great opportunity to study the genetic basis of CHC divergence between sister species. As a basis for further genome-wide studies high-quality genomes are needed. Here, we present the annotated draft genome for Crematogaster levior A. By combining the three most commonly used sequencing techniques-Illumina, PacBio, and Oxford Nanopore-we constructed a high-quality de novo ant genome. We show that even low coverage of long reads can add significantly to overall genome contiguity. Annotation of desaturase and elongase genes, which play a role in CHC biosynthesis revealed one of the largest repertoires in ants and a higher number of desaturases in general than in other Hymenoptera. This may provide a mechanistic explanation for the high diversity observed in C. levior CHC profiles.
社会性昆虫的成功在很大程度上与其高度先进的化学通讯系统交织在一起，该系统有助于识别和区分物种和巢伴、招募和分工。覆盖昆虫表皮的碳氢化合物不仅起到防水剂的作用，而且也是该通讯系统的主要组成部分。两种具有隐蔽性的 Crematogaster 物种与 Camponotus 蚂蚁共享巢穴，其表皮碳氢化合物 (CHC) 图谱表现出显著的多样性。因此，这种共生系统为研究姐妹种之间 CHC 差异的遗传基础提供了绝佳的机会。作为进一步进行全基因组研究的基础，需要高质量的基因组。在这里，我们呈现了 Crematogaster levior A 的注释草案基因组。通过结合三种最常用的测序技术——Illumina、PacBio 和 Oxford Nanopore，我们构建了一个高质量的从头蚂蚁基因组。我们表明，即使是低覆盖率的长读长也可以显著提高基因组的连续性。参与 CHC 生物合成的去饱和酶和延长酶基因的注释揭示了蚂蚁中最大的基因库之一，并且一般来说去饱和酶的数量比其他膜翅目昆虫更多。这可能为我们观察到的 C. levior CHC 图谱中的高度多样性提供了一种机制解释。
