Abstract：
Adipokinetic hormone (AKH) is a neuropeptide produced in the insect corpora cardiaca that plays an essential role in mobilising carbohydrates and lipids from the fat body to the haemolymph. AKH acts by binding to a rhodopsin-like G protein-coupled receptor (GPCR), the adipokinetic hormone receptor (AKHR). In this study, we tackle AKH ligand and receptor gene evolution as well as the evolutionary origins of AKH gene paralogues from the order Blattodea (termites and cockroaches). Phylogenetic analyses of AKH precursor sequences point to an ancient AKH gene duplication event in the common ancestor of Blaberoidea, yielding a new group of putative decapeptides. In total, 16 different AKH peptides from 90 species were obtained. Two octapeptides and seven putatively novel decapeptides are predicted for the first time. AKH receptor sequences from 18 species, spanning solitary cockroaches and subsocial wood roaches as well as lower and higher termites, were subsequently acquired using classical molecular methods and in silico approaches employing transcriptomic data. Aligned AKHR open reading frames revealed 7 highly conserved transmembrane regions, a typical arrangement for GPCRs. Phylogenetic analyses based on AKHR sequences support accepted relationships among termite, subsocial (Cryptocercus spp.) and solitary cockroach lineages to a large extent, while putative post-translational modification sites do not greatly differ between solitary and subsocial roaches and social termites. Our study provides important information not only for AKH and AKHR functional research but also for further analyses interested in their development as potential candidates for biorational pest control agents against invasive termites and cockroaches.
摘要：
脂肪动力学激素（AKH）是一种在昆虫贲门语中产生的神经肽，在动员碳水化合物和脂质从脂肪体到血淋巴中起着至关重要的作用。AKH通过与视紫红质样G蛋白偶联受体（GPCR）结合而起作用，脂肪动力学激素受体（AKHR）。在这项研究中,我们研究了AKH配体和受体基因的进化，以及来自Blattodea（白蚁和蟑螂）的AKH基因旁系同源物的进化起源。AKH前体序列的系统发育分析指出，在Blaberoidea的共同祖先中，有一个古老的AKH基因复制事件，产生一组新的推定的十肽。总的来说,获得来自90个物种的16种不同的AKH肽。首次预测了两个八肽和七个假定的新的十肽。来自18个物种的AKH受体序列，跨越孤独的蟑螂和亚社会的木蟑螂以及较低和较高的白蚁，随后使用经典分子方法和使用转录组数据的计算机模拟方法获得。对齐AKHR开放阅读框显示7个高度保守的跨膜区，GPCRs的典型安排。基于AKHR序列的系统发育分析支持白蚁之间公认的关系，亚社会(隐cercusspp.)和单独的蟑螂谱系在很大程度上，而假定的翻译后修饰位点在孤独和亚社会蟑螂和社会白蚁之间没有很大差异。我们的研究不仅为AKH和AKHR功能研究提供了重要信息，而且还为对其发展为针对侵袭性白蚁和蟑螂的生物害虫防治剂的潜在候选物感兴趣的进一步分析提供了重要信息。
