Expression analysis of inhibitor of apoptosis and related caspases in the midgut and silk gland of the greater wax moth, Galleria mellonella, during metamorphosis and under starvation.

We cloned a cDNA encoding inhibitor of apoptosis (IAP) from the greater wax moth, Galleria mellonella. The deduced amino acid sequence showed that GmIAP contains two baculoviral IAP repeat (BIR) motifs, followed by a RING finger. The sequence comparison showed that GmIAP had high homology to lepidopteran IAPs and baculoviral IAPs, as well as dipteran IAPs. GmIAP transcript and its protein appeared in both the midgut and the silk gland during metamorphosis and starvation where cell death was detected by TUNEL test. IAP, and capases-1, -3, -4 and -6 appeared as at least two peaks in the midgut and silk gland during metamorphosis. Caspase-1 transcript appeared at the highest level among caspases, while caspase-3 and caspase-6 seemed to be the most relevant caspases to IAP during metamorphosis suggesting that IAP and caspases may be involved in a core apoptosis pathway in the wax moth as in flies and mosquitoes.