Molecular characterization of Ephestia kuehniella (Lepidoptera: Pyralidae) transferrin and its response to parasitoid Venturia canescens (Hymenoptera: Ichneumonidae Gravenhorst)

Abstract

In the present study, we characterized a full-length cDNA encoding a putative iron-binding protein transferrin from the lepidopteran Mediterranean flour moth (EkTrf, 2397 bp). The putative EkTrf is 683 amino acids with a molecular mass of approximately 76 kDa. The deduced amino acid sequence showed significant homology with other insect transferrins from Chilo suppressalis (76%), Galleria mellonella (75%), Plutella xylostella (72%), Manduca sexta (74%), Bombyx mori (73%), Spodoptera litura and (72%), Choristoneura fumiferana (71%). Northern blot analysis indicated that Ephestia transferrin mRNA was expressed in the last larval instars of both males and females and in the pupal developmental stages. EkTrf is expressed predominantly in the fat body and ovary tissues. Analysis of parasitized larva by the endoparasitoid Venturia canescens suggests that transferrin expression is induced following parasitoid challenge. Expression of EkTrf levels also increased upon bacterial infection at 6 h post treatment and remained high until 24 h. Similarly to other insect transferrins, EkTrf may play a role in immunity through its iron-binding capacity.