3.1 Identification and phylogenetic analysis of candidateGmolCXEs
Based on the bioinformatic analysis, 23 candidate GmolCXEs were identified in the larval head transcriptome of G. molesta . These sequences were named GmolCXE1-23 according to the similarity to known Lepidopteran CXEs and numbers of amino acids in open reading frames (ORFs) (Table 1). Among them, 15 GmolCXEs contained full-length ORFs, and the rest 8 sequences were partial. The 15 full-length GmolCXEs contain a conserved motif pattern including an oxyanion hole (GGA, etc.), a catalytic triad (S-Xa-E-Xb-H), and a conserved Ser active site (G-X-S-X-G) (Figure S2 and Table 2). The predicted theoretical isoelectric points of these esteases are ranged from 5.22 to 9.27, and calculated molecular masses varies from 58.79 kDa to 74.82 kDa (Table 2). Phylogenetic analysis showed that 23 putativeGmolCXEs are closely clustered into 7 different clades (Figure 1). These clades include moth antennal esterases (GmolCXE1 ,2 , 14 , 15 , 17 , 18 , 20 ), cuticular and antennal esterases (GmolCXE5 ), ß-esterases and pheromone esterases (GmolCXE13 , 21 ), lepidopteran juvenile hormone esterases (JHE) (GmolCXE7 ), mitochondrial and cytosolic esterases (GmolCXE3a , 3b , 4 , 6 , 10 ,12 , 16 ), α-esterases (GmolCXE8 , 9 ,11 , 19 ) and neuroligins (GmolCXE22 ).GmolCXE1 and GmolCXE13 are closely clustered withApolODE and ApolPDE of Antheraea Polyphemus , respectively (Figure 1). All sequence information of these 23GmolCXEs has been released in the GenBank database (Table 1).