Genome-wide identification and expression profiling of serine proteases and homologs in the diamondback moth, Plutella xylostella (L.)

Abstract

BackgroundSerine proteases (SPs) are crucial proteolytic enzymes responsible for digestion and other processes including signal transduction and immune responses in insects. Serine protease homologs (SPHs) lack catalytic activity but are involved in innate immunity. This study presents a genome-wide investigation of SPs and SPHs in the diamondback moth, Plutella xylostella (L.), a globally-distributed destructive pest of cruciferous crops.ResultsA total of 120 putative SPs and 101 putative SPHs were identified in the P. xylostella genome by bioinformatics analysis. Based on the features of trypsin, 38 SPs were putatively designated as trypsin genes. The distribution, transcription orientation, exon-intron structure and sequence alignments suggested that the majority of trypsin genes evolved from tandem duplications. Among the 221 SP/SPH genes, ten SP and three SPH genes with one or more clip domains were predicted and designated as PxCLIPs. Phylogenetic analysis of CLIPs in P. xylostella, two other Lepidoptera species (Bombyx mori and Manduca sexta), and two more distantly related insects (Drosophila melanogaster and Apis mellifera) showed that seven of the 13 PxCLIPs were clustered with homologs of the Lepidoptera rather than other species. Expression profiling of the P. xylostella SP and SPH genes in different developmental stages and tissues showed diverse expression patterns, suggesting high functional diversity with roles in digestion and development.ConclusionsThis is the first genome-wide investigation on the SP and SPH genes in P. xylostella. The characterized features and profiled expression patterns of the P. xylostella SPs and SPHs suggest their involvement in digestion, development and immunity of this species. Our findings provide a foundation for further research on the functions of this gene family in P. xylostella, and a better understanding of its capacity to rapidly adapt to a wide range of environmental variables including host plants and insecticides.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2243-4) contains supplementary material, which is available to authorized users.

Characterization and expression profiling of serine protease inhibitors in the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

“…The midgut of 4th-instar larvae had fewer number (5) of genes expressed among the four tissues, while the numbers of genes expressed in the heads of 4th-instar larvae, adult males and females were 32, 28 and 34, respectively. PxSPIs had inverse tissue distribution tendency when compared with PxSPs and PxSPHs (the highest numbers of SPs and SPHs were distributed in the midgut) [ 67 ]. Such a tendency was also documented in B. mori [ 43 ].…”

Clip-Domain Serine Protease Gene (LsCLIP3) Is Essential for Larval–Pupal Molting and Immunity in Lasioderma serricorne

“…Many CLIPs have been identified in many insect species at the genome level. For example, 42 CLIPs (including clipdomain SPHs) are known in Drosophila melanogaster (Ross et al, 2003;Veillard et al, 2016), 18 in Bombyx mori (Tanaka et al, 2008;Zhao et al, 2010), 42 in Manduca sexta (Zou et al, 2007;Cao et al, 2015), 13 in Plutella xylostella (Lin et al, 2015), and 25 in Pteromalus puparum (Yang et al, 2017). CLIPs represent a large gene family in insects, which can be divided into four distinct clades.…”

Optimization of recombinant bacteria expressing dsRNA to enhance insecticidal activity against a lepidopteran insect, Spodoptera exigua

“…Trypsin and chymotrypsin are serine proteases identified in midgut transcriptomes of several lepidopteran insects [ 14 ]. For example, there are 120 serine proteases in the genome of diamondback moth, Plutella xylostella , including 38 trypsins and 8 chymotrypsins [ 15 ]. Transcriptome analysis of the Asian corn borer, Ostrinia furnacalis , has identified 19 trypsins and 7 chymotrypsins [ 16 ].…”