Fig. 1: Genome-wide cloning and characterization of the APN gene family in P. xylostella.

a Synteny analysis of APN1-12 genes among four lepidopteran insects. b Phylogenetic analysis of the currently available 340 lepidopteran APN and other M1 aminopeptidases by maximum likelihood method based on the optimized LG+G model at 495 aligned amino acid positions. c The constitutive transcription profiles of PxAPN and other M1 aminopeptidase genes in midgut tissues of fourth-instar larvae from all the Bt-susceptible and -resistant P. xylostella strains as determined by qPCR analysis. For each gene, the expression fold changes are color-coded according to the gradient, magenta and green rectangles indicate significant up- and down-regulation, respectively (ratio >1.5-fold in either direction), whereas yellow rectangles indicate no significant transcription variations. Genes are organized according to their phylogenetic tree constructed by the maximum likelihood method based on the optimized LG+G+I model at 690 aligned amino acid positions. d The relative expression levels of PxAPN1 and PxAPN3a proteins in BBMV samples of fourth-instar larvae from different strains. Both the detection of PxAPN protein levels by Western blots (upper row) and quantitative estimation of band intensity by densitometry (graph) are presented. Data are presented as mean values (c) and mean values ± SEM (d), n = 3 biologically independent samples, *p < 0.05, **p < 0.01, ***p < 0.001, ns, not significant, one-way ANOVA with Holm–Sidak’s test was used in (c) and (d) for comparison. Source data are provided as a Source Data file.