Cloning and expression of a ferritin subunit for Galleria mellonella

Ferritin was purified from iron‐fed Galleria mellonella hemolymph by ultra centrifugation and FPLC (Superose 6). SDS‐PAGE revealed three bands of 26, 30, and 32 kDa. The ferritin 26 kDa subunit cDNA was obtained from RT‐PCR using primer designed from N‐terminal sequence analysis. 5′‐RACE was used to obtain the complete protein coding sequence. The sequence encodes a 211 amino acid polypeptide including a 20 amino acid leader peptide. An IRE (iron‐responsive element) sequence with a predicted stem‐loop structure was present in the 5′‐UTR of ferritin mRNA. Sequence alignment has a sequence identity with Calpodes ethlius (S)(74%), Drosophila melanogaster (50%), and Aedes aegypti (39%). Northern blot analysis indicated that there were 1.5‐ and 1.75‐fold increases in the expression of ferritin mRNA after iron‐fed fat body and midgut, respectively. Also, we confirmed that the ferritin mRNA is not expressed in adult ovary and testis. Arch. Insect Biochem. Physiol. 47:8–17, 2001. © 2001 Wiley‐Liss, Inc.