Data from: Succession and dynamics of Pristionchus nematodes and their microbiome during decomposition of Oryctes beetles on La Réunion Island

Insects and nematodes represent the most species-rich animal taxa and they occur together in a variety of associations. Necromenic nematodes of the genus Pristionchus are found on scarab beetles with more than 30 species known from worldwide samplings. However, little is known about the dynamics and succession of nematodes and bacteria during the decomposition of beetle carcasses. Here, we study nematode and bacterial succession of the decomposing rhinoceros beetle Oryctes borbonicus on La Réunion Island. We show that Pristionchus pacificus exits the arrested dauer stage seven days after the beetles´ deaths. Surprisingly, new dauers are seen after 11 days, suggesting that some worms return to the dauer stage after one reproductive cycle. We used high-throughput sequencing of the 16S rRNA genes of decaying beetles, beetle guts and nematodes to study bacterial communities in comparison to soil. We find that soil environments have the most diverse bacterial communities. The bacterial community of living and decaying beetles are more stable but one single bacterial family dominates the microbiome of decaying beetles. In contrast, the microbiome of nematodes is relatively similar even across different families. This study represents the first characterization of the dynamics of nematode-bacterial interactions during the decomposition of insects.昆虫与线虫(nematodes)是物种多样性最高的两类动物类群，二者可形成多种共生关系。尸生平咽线虫属(Pristionchus)的线虫常栖息于金龟子(scarab beetles)体表，目前全球采样已记录该属超过30个物种。然而，学界对金龟子尸体腐解过程中线虫与细菌的动态变化及群落演替仍知之甚少。本研究以留尼汪岛(La Réunion Island)上的腐解波旁犀金龟(Oryctes borbonicus)为研究对象，探究其腐解过程中的线虫与细菌群落演替。研究显示，太平洋平咽线虫(Pristionchus pacificus)会在宿主金龟子死亡7天后脱离滞育态(dauer stage)。令人意外的是，腐解第11天可观测到新的滞育个体，这表明部分线虫在完成一轮生殖周期后会重新进入滞育状态。本研究通过对腐解金龟子、金龟子肠道及线虫的16S核糖体RNA基因(16S rRNA genes)进行高通量测序，并以土壤菌群作为对照分析细菌群落组成。结果表明，土壤环境的细菌群落多样性最高；活体与腐解金龟子的细菌群落相对稳定，但腐解金龟子的微生物组(microbiome)会被单一细菌科主导。与之形成鲜明对比的是，即便来自不同分类科的线虫，其微生物组也相对相似。本研究首次揭示了昆虫腐解过程中线虫-细菌互作的动态变化规律。