School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK.
Department of Neuroscience, Psychology and Behaviour, University of Leicester, Adrian Building, University Road, Leicester, LE1 7RH, UK.
Sci Rep. 2020 Sep 29;10(1):15953. doi: 10.1038/s41598-020-72598-z.
Malpighian tubules, analogous to vertebrate nephrons, play a key role in insect osmoregulation and detoxification. Tubules can become infected with a protozoan, Malpighamoeba, which damages their epithelial cells, potentially compromising their function. Here we used a modified Ramsay assay to quantify the impact of Malpighamoeba infection on fluid secretion and P-glycoprotein-dependent detoxification by desert locust Malpighian tubules. Infected tubules have a greater surface area and a higher fluid secretion rate than uninfected tubules. Infection also impairs P-glycoprotein-dependent detoxification by reducing the net rhodamine extrusion per surface area. However, due to the increased surface area and fluid secretion rate, infected tubules have similar total net extrusion per tubule to uninfected tubules. Increased fluid secretion rate of infected tubules likely exposes locusts to greater water stress and increased energy costs. Coupled with reduced efficiency of P-glycoprotein detoxification per surface area, Malpighamoeba infection is likely to reduce insect survival in natural environments.
马氏管类似于脊椎动物的肾单位，在昆虫的渗透调节和解毒中发挥着关键作用。马氏管可能会被原生动物马氏管变形虫感染，从而破坏其上皮细胞，可能会影响其功能。在这里，我们使用改良的拉姆齐测定法来量化马氏管变形虫感染对沙漠蝗马氏管液体分泌和 P-糖蛋白依赖性解毒的影响。与未感染的马氏管相比，感染的马氏管具有更大的表面积和更高的液体分泌速率。感染还通过减少每单位表面积的罗丹明净外排量来损害 P-糖蛋白依赖性解毒。然而，由于表面积和液体分泌率的增加，感染的马氏管的总净外排量与未感染的马氏管相似。感染的马氏管分泌更多的液体可能会使蝗虫面临更大的水胁迫和更高的能量成本。再加上每单位表面积的 P-糖蛋白解毒效率降低，马氏管变形虫感染很可能会降低昆虫在自然环境中的存活率。
