Gene expression data was used to identify key enzymes in the gut of a major storage pest, the red flour beetle.  The expression of genes encoding enzymes in the major feeding stages, larvae and adults, was compared to that of non-feeding stages, eggs and pupae.  The data contribute to the comprehensive study of protein digestion in the beetle and identify key enzymes to target for pest control strategies.




The red flour beetle, Tribolium castaneum, is a major agricultural pest responsible for considerable loss of stored grain and cereal products worldwide. T. castaneum larvae have a highly compartmentalized gut, with cysteine peptidases mostly in the acidic anterior part of the midgut that are critical to the early stages of food digestion. In previous studies, we described 26 putative cysteine peptidase genes in T. castaneum (types B, L, O, F, and K) located mostly on chromosomes 3, 7, 8, and 10. In the present study, we hypothesized that specific cysteine peptidase genes could be associated with digestive functions for food processing based on comparison of gene expression profiles in different developmental stages, feeding and non-feeding. RNA-Seq was used to determine the relative expression of cysteine peptidase genes among four major developmental stages (egg, larvae, pupae, and adult) of T. castaneum. We also compared cysteine peptidase genes in T. castaneum to those in other model insects and coleopteran pests. By combining transcriptome expression, phylogenetic comparisons, response to dietary inhibitors, and other existing data, we identified key cysteine peptidases that T. castaneum larvae and adults use for food digestion, and thus new potential targets for biologically-based control products.



Perkin L, Elpidina EN, Oppert B. (2016) Expression patterns of cysteine peptidase genes across the Tribolium castaneum life cycle provide clues to biological function. PeerJ4:e1581