Indeed, according to literature data, defective or inhibited trehalases may be associated in insects to altered sugar metabolism (Wegener et al

Indeed, according to literature data, defective or inhibited trehalases may be associated in insects to altered sugar metabolism (Wegener et al., 2003) or to morphological abnormalities (Zhang et al., 2012) suggesting that gene duplication could result in a sub-functionalization of trehalases in Hemiptera. The role of acid trehalases in insects is still unknown and horizontal gene transfer events from bacteria or fungi to insects could be involved. Acid trehalases are mainly described in bacteria and fungi (Destruelle et al., 1995; DEnfert and Fontaine, 1997; Inagaki et al., 2001; Murata et al., 2001) and the origin of such genes in insect genomes is still unexplained. In view of the consideration that progresses in understanding the molecular characterization of trehalase could favor the use of these proteins as a novel target for insecticides, in the present study we analyzed the evolutionary history of the and gene families has been performed looking at 40 insect species representatives of five different orders. For each species, genes coding for trehalase, trehalase-like, acid trehalase and acid trehalase-like genes have been identified by retrieving the available coding sequences (even if it was not previously annotated) from NCBI online databases1. When trehalase genes were not annotated, transcript sequence from the phylogenetically nearest species has been used to find trehalase genes in the genome of the target species, i.e., (Diptera, Drosophilidae) using annotated gene. sequences were retrieved from databases2. Nucleotide sequences of exons from NCBI predictions have been used to build and gene family phylogenies. For the construction of the trehalase phylogenetic tree, (Nematoda: Rhabditidae), the tardigrad (Tardigrada, Hypsibiidae) and the crustacean (Crustacea: Branchiopoda). Exons sequences were analyzed with (Wernersson, 2006) and the predicted coding sequences were aligned with in (Tamura et al., 2007). The alignment was trimmed to contain only the region between the first and the last conserved domains: VIVPGGR, QWDYPNAWPP, DSKTFVDM, RSQPPL, PRPESYREDY, and ELKAA and glycine rich domain GGGEYE (Barraza and Snchez, 2013; Xie et al., 2013). The Maximum Likelihood phylogenetic tree was constructed with (Silvestro and Michalak, 2011) (ML + throught bootstrap, 10 runs, 1000 reps, jModeltest and GTRGAMMAI, SCH 50911 outgroup SCH 50911 “type”:”entrez-nucleotide”,”attrs”:”text”:”EU893513.1″,”term_id”:”209755533″,”term_text”:”EU893513.1″EU893513.1). The phylogenetic tree was visualized and edited CD350 in (Letunic and Bork, 2006). For each conserved domain in each sequence, the (Petersen et al., 2011) to predict the presence of signal peptides and to predict transmembrane domains (Sonnhammer et al., 1998). Acid trehalases isoforms have been compared considering the distribution of six consensus discrete motifs, besides the catalytic domain: a transmembrane span (LFFFFFFFLCFSFTTSML), a cAMP-dependent phosphorylation site (RRXS), an EF-like Ca2+-binding motif (DTXGDXQITIXD), two trehalase signature motifs 1 and 2, (PGGRFXEXYXWDXY) and (QWDXPX[G/A]W[P/A/S]P), respectively, and the glycosyl phosphatidyl inositol (GPI) membrane anchor motif (CRTNYGYSAA) (Barraza and Snchez, SCH 50911 2013). Genomic scaffolds containing and genes were compared looking for synteny and co-linearity among insect species by analysis of the neighboring genes located in the same scaffold/contigs hosting and genes. Results Identification of and Genes Currently Available in DNA Databases The search of Genbank databases allowed us to identify 160 genes in 14 species (Table 1). Except for Dipterans, the other insect taxa have experienced specific gene duplications and maintained multiple gene copies in their genomes. Hemipteran genome showed the highest number of gene duplications (54 copies in 7 species). The pea aphid possessed the highest number of gene copies with 13 genes, followed by (Coleoptera: Nitidulidae) with 11 genes and the two aphid species and with 8 copies, respectively (Table 1 and Supplementary Table S1). genome possesses a pseudogene with a high similarity to plant trehalases, but with a partial coding sequence due to a large deletion in the gene. possessed two genes (LOC105397091 and LOC105395616) with high level of sequence similarity with a gene encoded by (Bacteria: Enterobacteriacea; scaffold “type”:”entrez-nucleotide”,”attrs”:”text”:”CP015227″,”term_id”:”1020388573″,”term_text”:”CP015227″CP015227). Table 1 List of species and genomes considered in the present study for the search of treh genes and transcripts. genesgenes. Differently, multiple genes coding for acid trehalases have been identified in (Diptera: Tephritidae) since they possessed duplicated genes as well (LOC100159015, LOC100167863, MYZPE13164_G006, MYZPE13164_G006, LOC105394851, LOC105386635 and LOC106624493, LOC106624487, LOC106622467) and (Diptera: Culicidae) where 11 genes have been identified (LOC109417656, LOC109417657, LOC109417661, LOC109417662, LOC109417664, LOC109622150, LOC109622151, LOC109622152, LOC109622154, LOC109622125, and LOC109622155). En exception to these previous statements is (Hymenoptera: Apididae), where an “type”:”entrez-nucleotide”,”attrs”:”text”:”AP014808.1″,”term_id”:”766541428″,”term_text”:”AP014808.1″AP014808.1 and “type”:”entrez-nucleotide”,”attrs”:”text”:”CP000413.1″,”term_id”:”116094265″,”term_text”:”CP000413.1″CP000413.1) has been identified. Trehalase Phylogenetic Tree Phylogenetic analysis evidenced that at least one member of the and subfamily was present in each species considered, except for Diptera that didnt possess any gene (Figure 1 and Supplementary Figure S1). Open in a separate window FIGURE 1 Phylogenetic tree of genes and protein isoform diversity in insects and other taxa. For each paralog only one transcript variant has been considered while protein diversity represents all the transcript variants predicted by NCBI algorithms. subfamily is represented by a higher number of members (110/160 genes/n of and genes) which encode for lesser conserved trehalase isoforms, in respect to subfamily. Coleopteran and hemipteran genes, for instance, had species-specific duplication events involving.