Yang Liu, Denlinger David L, Piermarini Peter M
Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, United States.
Department of Entomology, The Ohio State University, Columbus, OH, United States; Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, United States.
J Insect Physiol. 2017 Apr;98:141-148. doi: 10.1016/j.jinsphys.2016.12.005. Epub 2016 Dec 27.
Adult females of the mosquito Culex pipiens entering diapause increase sugar water ingestion and reduce evaporative water loss, but how these attributes of the diapause program impact activity of the renal excretory system remains unknown. Here we compared the renal excretory capacity of diapausing and non-diapausing females, as well as the molecular expression of aquaporin (AQP) genes that encode channels involved in transporting water and/or small metabolites. Baseline urine excretion rates in diapausing mosquitoes were higher than in those of their non-diapausing counterparts, possibly a consequence of the intense sugar feeding associated with diapause. But, diapausing mosquitoes exhibited a much lower capacity for diuresis than non-diapausing mosquitoes. The suppressed diuretic capacity likely reflects reduced investment in the energetically-expensive post-prandial diuresis, an event not observed in diapausing mosquitoes. The mRNA expression levels of two genes encoding AQPs, Eglp1 and Aqp12L, in diapausing mosquitoes were down-regulated (on day 14) and up-regulated (on both days 3 and 14), respectively, in whole body samples. These changes were not evident in the excretory system (i.e., Malpighian tubules and hindgut), which showed no differential expression of AQPs as a function of diapause. Several AQP mRNAs were, however, differentially expressed in the midgut, ovaries, and abdominal body wall of diapausing mosquitoes, suggesting that AQPs in these tissues may be playing important non-excretory roles that are unique to diapause physiology.
进入滞育状态的致倦库蚊成年雌蚊会增加糖水摄入量并减少蒸发失水量，但滞育程序的这些特性如何影响肾脏排泄系统的活动仍不清楚。在这里，我们比较了滞育雌蚊和非滞育雌蚊的肾脏排泄能力，以及编码参与运输水和/或小代谢物通道的水通道蛋白（AQP）基因的分子表达。滞育蚊子的基础尿排泄率高于非滞育蚊子，这可能是滞育期间大量摄食糖分的结果。但是，滞育蚊子的利尿能力比非滞育蚊子低得多。利尿能力的抑制可能反映了对能量消耗大的餐后利尿的投入减少，这一现象在滞育蚊子中未观察到。在滞育蚊子的全身样本中，编码AQP的两个基因Eglp1和Aqp12L的mRNA表达水平分别下调（第14天）和上调（第3天和第14天）。这些变化在排泄系统（即马氏管和后肠）中不明显，排泄系统中未显示AQP随滞育而有差异表达。然而，几种AQP mRNA在滞育蚊子的中肠、卵巢和腹部体壁中差异表达，这表明这些组织中的AQP可能在滞育生理中发挥着独特的重要非排泄作用。
