Antennal Transcriptome Analysis and Comparison of Chemosensory Gene Families in Two Closely Related Noctuidae Moths, Helicoverpa armigera and H. assulta

Abstract

To better understand the olfactory mechanisms in the two lepidopteran pest model species, the Helicoverpa armigera and H. assulta, we conducted transcriptome analysis of the adult antennae using Illumina sequencing technology and compared the chemosensory genes between these two related species. Combined with the chemosensory genes we had identified previously in H. armigera by 454 sequencing, we identified 133 putative chemosensory unigenes in H. armigera including 60 odorant receptors (ORs), 19 ionotropic receptors (IRs), 34 odorant binding proteins (OBPs), 18 chemosensory proteins (CSPs), and 2 sensory neuron membrane proteins (SNMPs). Consistent with these results, 131 putative chemosensory genes including 64 ORs, 19 IRs, 29 OBPs, 17 CSPs, and 2 SNMPs were identified through male and female antennal transcriptome analysis in H. assulta. Reverse Transcription-PCR (RT-PCR) was conducted in H. assulta to examine the accuracy of the assembly and annotation of the transcriptome and the expression profile of these unigenes in different tissues. Most of the ORs, IRs and OBPs were enriched in adult antennae, while almost all the CSPs were expressed in antennae as well as legs. We compared the differences of the chemosensory genes between these two species in detail. Our work will surely provide valuable information for further functional studies of pheromones and host volatile recognition genes in these two related species.

Molecular identification and sex distribution of two chemosensory receptor families in Athetis lepigone by antennal transcriptome analysis

“…Consistent with other moths (Bengtsson et al, 2012;Feng et al, 2015;Zhang et al, 2013Zhang et al, , 2015, the AlepORco gene also displayed a very high mRNA abundance. Many previous studies showed that ORco could act as a chaperone and dimerization partner for other ORs, forming a ligand gated ion channel to specific ligands (Krieger et al, 2003(Krieger et al, , 2005Nakagawa et al, 2005;Xu and Leal, 2013), and ORco was more highly conserved in insects than other ORs (Krieger et al, 2003;Leal, 2013;Robertson et al, 2003;Vogt, 2005), thus it required more ORco transcripts to activate different ORs.…”

“…The OR data set contained 61 sequences from A. lepigone, and 202 from other insects (Krieger et al, 2004;Tanaka et al, 2009;Zhang et al, 2015). The IR data set contained 19 sequences from A. lepigone, and 166 from other insects (Bengtsson et al, 2012;Croset et al, 2010;Glaser et al, 2013;Grosse-Wilde et al, 2011;Liu et al, 2014a;Poivet et al, 2013;Zhan et al, 2011).…”

“…Compared with initial gene cloning by designing degenerate primers and screening cDNA libraries (Krieger et al, 2002(Krieger et al, , 2004Liu et al, 2013;Mitsuno et al, 2008;Sakurai et al, 2004;Zhang et al, 2010), RNA-seq (next generation sequencing techniques) was considered to be more time-saving, cost, and efficient. Recently, several chemosensory receptor genes have been identified from different lepidopteran insects whose genomes have not been sequenced, such as Spodoptera littoralis (Legeai et al, 2011), Cydia pomonella (Bengtsson et al, 2012), Helicoverpa assulta (Xu et al, 2015;Zhang et al, 2015), and Sesamia inferens .…”

Comparing the Expression of Olfaction-Related Genes in Gypsy Moth (Lymantria dispar) Adult Females and Larvae from One Flightless and Two Flight-Capable Populations

“…This report represents an expansive characterization of the chemosensory transcripts and their encoded proteins of L. dispar, and increases the number of available olfactory-related sequences for Lepidopteran species of agricultural relevance. Our results may also help unveil how the expression of chemosensory genes changes throughout insect development and as a result of speciation processes, together with similar reports for other species (Poivet et al, 2013;Zhang et al, 2014Zhang et al, , 2015Walker et al, 2016).…”

“…Antennal transcriptomes are available for insect species belonging to several orders, including Diptera, Coleoptera, and Lepidoptera (Grosse-Wilde et al, 2011;Andersson et al, 2013;Rinker et al, 2013;Leitch et al, 2015;Zhang et al, 2015). Within the Lepidoptera, the transcriptomes of model species such as B. mori, D. plexippus, H. melpomene, H. virescens, and M. sexta have been thoroughly investigated (Krieger et al, 2003(Krieger et al, , 2004Nakagawa et al, 2005;Wanner et al, 2007;Wanner and Robertson, 2008;Tanaka et al, 2009;Briscoe et al, 2013;Koenig et al, 2015;van Schooten et al, 2016).…”