Expressed sequence tags from Diabrotica virgifera virgifera midgut identify a coleopteran cadherin and a diversity of cathepsins

Blair D. Siegfried, University of Nebraska - Lincoln
N. Waterfield, Department of Biology and Biochemistry, University of Bath, Bath, UK
R. H. ffrench-Constant, Department of Biology and Biochemistry, University of Bath, Bath, UK

Document Type Article

Published in Insect Molecular Biology 14:2 (2005), pp. 137–143; doi: 10.1111/j.1365-2583.2004.00538.x Copyright © 2005 The Royal Entomological Society; published by Blackwell Publishing. Used by permission.

Abstract

The Western corn rootworm is the major pest of corn in the USA and has recently become the target for insect-resistant transgenic crops. Transgenic crops have switched the focus for identifying insecticide targets from the insect nervous system to the midgut. Here we describe a collection of 691 sequences from the Western corn rootworm midgut, 27% of which predict proteins with no matches in current databases. Of the remaining sequences, most predict proteins with either catalytic (62%) or binding (19%) functions, as expected for proteins expressed in the insect midgut. The utility of this approach for the identification of targets for novel toxins is demonstrated by analysis of the first coleopteran cadherin gene, a putative Bt receptor, and a large class of cysteine-proteases, the cathepsins.