Department of Forensic Science, School of Basic Medical Sciences, Central South University, Changsha, Hunan, China.
OE Biotech Co. Ltd, Shanghai, China.
Parasit Vectors. 2023 Oct 17;16(1):364. doi: 10.1186/s13071-023-05973-0.
Heat tolerance is a distinct abiotic factor affecting the distribution and abundance of insects. Gut microbiota can contribute to host fitness, thereby increasing resistance to abiotic stress conditions. In this study, Sarcophaga peregrina is closely associated with human life in ecological habits and shows remarkable adaptability to daily and seasonal temperature fluctuations. To date, the role of gut microbiota in S. peregrina response to heat stress and its influence on the host phenotypic variability remain poorly studied.
We exposed S. peregrina to heat stress at 40 °C for 3 h every day throughout the developmental stages from newly hatched larva to adult, after which gut DNA was extracted from third-instar larvae, early pupal stage, late pupal stage, and newly emerged adults, respectively. Then, 16S rRNA microbial community analyses were performed.
Firstly, we analyzed whether heat stress could have an impact on the life history traits of S. peregrina and showed that the growth rate of larvae was higher and the developmental time was significantly shorter after heat stress. We then proposed the role of the gut microbiota in the heat tolerance of S. peregrina, which indicated that the bacterial abundance and community structure changed significantly after heat tolerance. In particular, the relative abundance of Wohlfahrtiimonas and Ignatzschineria was higher in the third-instar larval larvae; the former increased and the latter decreased significantly after heat stress. To further explore the effect of disturbing the microbial community on thermotolerant phenotype, newly hatched larvae were fed with amikacin under heat stress, which indicated that the larval length and the whole developmental cycle was significantly shorter.
This study indicated that Wohlfahrtiimonas and Ignatzschineria should play an important role in the post-feeding stage under heat stress, but further study is still needed. In general, heat tolerance can affect the gut microbial community structure, which in turn affects the fitness of the host.
耐热性是影响昆虫分布和丰度的一个独特非生物因素。肠道微生物群可以促进宿主的适应性，从而提高对非生物胁迫条件的抵抗力。在这项研究中，麻蝇与人类的生态习性密切相关，对日常和季节性温度波动表现出显著的适应性。迄今为止，肠道微生物群在麻蝇对热应激的反应及其对宿主表型变异性的影响方面的作用仍知之甚少。
我们在整个发育阶段（从刚孵化的幼虫到成虫）中，每天将麻蝇暴露在 40°C 的热应激下 3 小时，然后分别从三龄幼虫、早期蛹期、晚期蛹期和新羽化的成虫中提取肠道 DNA。然后，进行 16S rRNA 微生物群落分析。
首先，我们分析了热应激是否会对麻蝇的生活史特征产生影响，结果表明热应激后幼虫的生长速度更高，发育时间明显缩短。然后，我们提出了肠道微生物群在麻蝇耐热性中的作用，表明耐热性后细菌丰度和群落结构发生了显著变化。特别是，三龄幼虫中沃氏菌和 Ignatzschineria 的相对丰度较高；热应激后，前者增加，后者显著减少。为了进一步探讨干扰微生物群落对耐热表型的影响，我们在热应激下用阿米卡星喂养刚孵化的幼虫，结果表明幼虫的长度和整个发育周期明显缩短。
本研究表明，沃氏菌和 Ignatzschineria 在热应激下的摄食后阶段应该发挥重要作用，但仍需要进一步研究。总的来说，耐热性可以影响肠道微生物群落结构，进而影响宿主的适应性。
