Kakani Parik, Gupta Lalita, Kumar Sanjeev
Molecular Parasitology and Vector Biology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science (BITS), Pilani, India.
Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India.
Front Physiol. 2020 Sep 8;11:572340. doi: 10.3389/fphys.2020.572340. eCollection 2020.
The dynamic nature of mosquito gut microbiome is associated with different stages of development and feeding behaviors. Therefore, mosquito gut harbors a wide range of endogenous microbes that promote numerous life processes such as, nutrition, reproduction and immunity. In addition, gut microbiota also play an important role in the regulation of (malaria parasite) development. Thus, understanding the mechanism of microbial homeostasis in mosquito gut might be one of the strategies to manipulate malaria parasite development. In the present study, we characterized a 692 amino acids long secreted midgut heme-peroxidase 2 (AsHPX2) in , the major Indian malaria vector. The presence of putative integrin binding motifs, LDV (Leu-Asp-Val), indicated its peroxinectin-like nature. Our phylogenetic analysis revealed that AsHPX2 is a Culicinae lineage-specific gene. RNA interference (RNAi)-mediated silencing of AsHPX2 gene significantly enhanced the growth of midgut bacteria in sugar-fed mosquitoes against sham-treated controls. Interestingly, blood-feeding drastically reduced AsHPX2 gene expression and enhanced the growth of midgut bacteria. These results revealed a negative correlation between the expression of AsHPX2 gene and gut bacterial growth. We proposed that AsHPX2, being a mosquito-specific gene, might serve as a "potent target" to manipulate midgut microbiota and vector competence.
蚊子肠道微生物群的动态性质与不同的发育阶段和摄食行为相关。因此，蚊子肠道中含有多种内源性微生物，这些微生物促进了许多生命过程，如营养、繁殖和免疫。此外，肠道微生物群在（疟原虫）发育的调节中也起着重要作用。因此，了解蚊子肠道中微生物稳态的机制可能是控制疟原虫发育的策略之一。在本研究中，我们对印度主要疟疾传播媒介体内一种692个氨基酸长的分泌型中肠血红素过氧化物酶2（AsHPX2）进行了表征。推测的整合素结合基序LDV（亮氨酸-天冬氨酸-缬氨酸）的存在表明其具有过氧化物结合蛋白样性质。我们的系统发育分析表明，AsHPX2是库蚊亚科谱系特异性基因。RNA干扰（RNAi）介导的AsHPX2基因沉默显著增强了以糖为食的蚊子中肠细菌相对于假处理对照的生长。有趣的是，吸血显著降低了AsHPX2基因的表达并增强了中肠细菌的生长。这些结果揭示了AsHPX2基因表达与肠道细菌生长之间的负相关关系。我们提出，作为一种蚊子特异性基因，AsHPX2可能作为一个“有效靶点”来控制中肠微生物群和媒介能力。
