Department of Biological Sciences, California State University San Marcos, San Marcos, CA 92096, USA.
Department of Biology, San Diego State University, San Diego, CA 92182, USA.
G3 (Bethesda). 2022 Mar 4;12(3). doi: 10.1093/g3journal/jkac001.
Dinocampus coccinellae (Hymenoptera: Braconidae) is a generalist parasitoid wasp that parasitizes >50 species of predatory lady beetles (Coleoptera: Coccinellidae), with thelytokous parthenogeny as its primary mode of reproduction. Here, we present the first high-quality genome of D. coccinellae using a combination of short- and long-read sequencing technologies, followed by assembly and scaffolding of chromosomal segments using Chicago + HiC technologies. We also present a first-pass ab initio and a reference-based genome annotation and resolve timings of divergence and evolution of (1) solitary behavior vs eusociality, (2) arrhenotokous vs thelytokous parthenogenesis, and (3) rates of gene loss and gain among Hymenopteran lineages. Our study finds (1) at least 2 independent origins of eusociality and solitary behavior among Hymenoptera, (2) 2 independent origins of thelytokous parthenogenesis from ancestral arrhenotoky, and (3) accelerated rates of gene duplications, loss, and gain along the lineages leading to D. coccinellae. Our work both affirms the ancient divergence of Braconid wasps from ancestral Hymenopterans and accelerated rates of evolution in response to adaptations to novel hosts, including polyDNA viral coevolution.
双带盘腹蛛（膜翅目：盘腹蛛科）是一种广食性寄生蜂，寄生在 50 多种捕食性瓢虫（鞘翅目：瓢虫科）上，其主要繁殖方式为孤雌生殖。在这里，我们使用短读长和长读长测序技术相结合，首次对 D. coccinellae 进行了高质量基因组测序，然后使用芝加哥+HiC 技术对染色体片段进行组装和支架构建。我们还进行了首次从头注释和基于参考的基因组注释，并确定了（1）独居行为与群居性、（2）孤雌生殖与两性生殖、（3）膜翅目谱系中基因丢失和获得的速率的分化和进化时间。我们的研究发现（1）膜翅目至少有 2 次独居行为和群居性的独立起源，（2）有丝分裂孤雌生殖从有性生殖的祖先中独立起源了 2 次，以及（3）沿着导致双带盘腹蛛的谱系，基因复制、丢失和获得的速度加快。我们的工作既证实了盘腹蛛科与原始膜翅目之间的古老分化，又证实了为适应新宿主而加速进化的速度，包括多 DNA 病毒的共同进化。
