Functional characterization of an allatotropin receptor expressed in the corpora allata of mosquitoes

Abstract

Allatotropin is an insect neuropeptide with pleiotropic actions on a variety of different tissues. In the present work we describe the identification, cloning and functional and molecular characterization of an Aedes aegypti allatotropin receptor (AeATr) and provide a detailed quantitative study of the expression of the AeATr gene in the adult mosquito. Analysis of the tissue distribution of AeATr mRNA in adult female revealed high transcript levels in the nervous system (brain, abdominal, thoracic and ventral ganglia), corpora allata-corpora cardiaca complex and ovary. The receptor is also expressed in heart, hindgut and male testis and accessory glands. Separation of the corpora allata (CA) and corpora cardiaca followed by analysis of gene expression in the isolated glands revealed expression of the AeATr primarily in the CA. In the female CA, the AeATr mRNA levels were low in the early pupae, started increasing 6 hours before adult eclosion and reached a maximum 24 hours after female emergence. Blood feeding resulted in a decrease in transcript levels. The pattern of changes of AeATr mRNA resembles the changes in JH biosynthesis. Fluorometric Imaging Plate Reader recordings of calcium transients in HEK293 cells expressing the AeATr showed a selective response to A. aegypti allatotropin stimulation in the low nanomolar concentration range. Our studies suggest that the AeATr play a role in the regulation of JH synthesis in mosquitoes.

In silico cloning of genes encoding neuropeptides, neurohormones and their putative G-protein coupled receptors in a spider mite

“…6). Its receptor is likely encoded by tetur23g00700, a GPCR which has strong similarity (best BLAST e-value 6e-110) to the various insect allatotropin receptors recently characterized (Yamanaka et al, 2008;Vuerinckx et al, 2011;Horodyski et al, 2011;Nouzova et al, 2012) and which clusters tightly with those receptors on the phylogenetic tree (Fig. S1).…”

Families of allatoregulator sequences: a 2011 perspective1This review is part of a virtual symposium on recent advances in understanding a variety of complex regulatory processes in insect physiology and endocrinology, including development, metabolism, cold hardiness, food intake and digestion, and diuresis, through the use of omics technologies in the postgenomic era.

“…Mammalian orexin/hypocretin-like receptors have been characterized as orthologous receptors for AT (Yamanaka et al 2008). Two AT receptors have been identified in B. mori (BNGR-16 and BNGR-5) (Yamanaka et al 2008) and A. aegypti (AeATRa and AeATRb) (Nouzova et al 2011). BNGR-16 was described as the functional receptor in B. mori (Yamanaka et al 2008), and the two paralogous receptor genes in A. aegypti encode nearly identical receptor sequences (Nouzova et al 2011).…”

“…Two AT receptors have been identified in B. mori (BNGR-16 and BNGR-5) (Yamanaka et al 2008) and A. aegypti (AeATRa and AeATRb) (Nouzova et al 2011). BNGR-16 was described as the functional receptor in B. mori (Yamanaka et al 2008), and the two paralogous receptor genes in A. aegypti encode nearly identical receptor sequences (Nouzova et al 2011). One receptor has been identified in M. sexta (Horodyski et al 2011) and T. castaneum (Vuerinckx et al 2011).…”

“…This receptor is not expressed in the CC. Very low levels were found in the Malpighian tubules and gut (Nouzova et al 2011). The B. mori AT receptor, which provided a selection criterion for previously discussed receptors, has unusual localization and, perhaps, mode of action.…”

Allatotropin inhibits juvenile hormone biosynthesis by the corpora allata of adult Bombyx mori

“…The regulatory mechanisms of JH biosynthesis in the adult stage have also been well studied in several insect species, in particular, cockroaches (reviewed by Stay and Tobe, 2007;Marchal et al, 2013) and mosquitoes (Noriega, 2004;Mayoral et al, 2009;Nouzova et al, 2011Nouzova et al, , 2012Pérez-Hedo et al, 2013;Nyati et al, 2013;Rivera-Perez et al, 2013). Allatotropin (AT) and allatostatin (AST) are two major neuropeptide hormones that control JH synthesis during the adult stage (Weaver and Audsley, 2009;Goodman and Granger, 2005).…”