Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada L5L 1C6.
Mol Cell Endocrinol. 2011 Jan 1;331(1):79-88. doi: 10.1016/j.mce.2010.08.012. Epub 2010 Aug 24.
Rhodnius prolixus undergoes a period of rapid diuresis after ingesting large blood meals. Neurohormones with either diuretic or anti-diuretic activity control diuresis by acting on several tissues including the Malpighian tubules. One of the neurohormones that potentially plays a role in diuresis is diuretic hormone 31 (DH(31)) which belongs to the insect calcitonin-like family of diuretic hormones. Here we determine the complete cDNA sequences of three Rhopr-DH(31) splice variants (Rhopr-DH(31)-A, Rhopr-DH(31)-B and Rhopr-DH(31)-C) and characterize their expression in unfed fifth-instar R. prolixus. Reverse transcriptase-PCR demonstrates that Rhopr-DH(31) is predominantly expressed in the central nervous system (CNS) of unfed fifth-instars. However, the expression of the three splice variants differs with Rhopr-DH(31)-B expression being the highest followed by Rhopr-DH(31)-A and Rhopr-DH(31)-C, as determined using semi-quantitative Southern blot analysis. Fluorescent in situ hybridization reveals that Rhopr-DH(31) is expressed in a variety of cells in the CNS, including some neurosecretory cells.
在摄入大量血液后，巨螯蜚蠊会经历一段快速利尿期。具有利尿或抗利尿活性的神经激素通过作用于包括马氏管在内的几种组织来控制利尿。可能在利尿中起作用的神经激素之一是利尿激素 31（DH(31)），它属于昆虫降钙素样利尿激素家族。在这里，我们确定了三种 Rhopr-DH(31)剪接变体（Rhopr-DH(31)-A、Rhopr-DH(31)-B 和 Rhopr-DH(31)-C）的完整 cDNA 序列，并研究了它们在未进食的五龄幼虫中的表达情况。逆转录 PCR 表明，Rhopr-DH(31)主要在未进食的五龄幼虫的中枢神经系统（CNS）中表达。然而，三种剪接变体的表达情况不同，Rhopr-DH(31)-B 的表达量最高，其次是 Rhopr-DH(31)-A 和 Rhopr-DH(31)-C，这可以通过半定量 Southern blot 分析来确定。荧光原位杂交显示，Rhopr-DH(31)在 CNS 中的多种细胞中表达，包括一些神经分泌细胞。
