Musca domestica hexamerins
De M., Marinotti O., James AA., De Bianchi AG.
During the Musca life cycle a larval hexamerin (arylphorin) and an adult female hexamerin (NVFP) was characterized, cDNAs from Musca hexamerins were cloned and characterized. The larval hexamerin (Hex-L) cDNA (A1,378 bp) showed similarityI with calliphorin from C.vicina and LSP1 from D.melanogaster. This eDNA recognizes a larval fat body specific mRNA (2.6 kb) with a temporal expression profile suggesting that expression of Hex-L is controlled at level of transcription. A female-specific non-vitellogenic Musca protein (Hex-F) was characterized. It is a 430 kDa hexamer made up of 7() kDa subunits. Amino acid analyses of Hex-F show a moderate aromatic amino acid content (12%) and a low methionine content (10%) in relation with other hexamerins of arylphorin group. Three main Hex-F eDNA-clones were characterized: F1(912 bp), F2 (2,202 bp)and (F3 2,100 bp). The sequence of these three clones reveals a homology with other insect hexamerin genes. The highest similarity has been obtained with the LSP2 gene of D.rnelanogaster. The temporal expression profiles of mRNAs that hybridize with the F1, F2 and F3 clones, as well as the recognition of an F2-derived recombinant protein by anti-Hex-F serum allows us to conclude that these cDNAs are partial eDNA clones of Musca Hex-F genes. Southern blot experiments show that Hex-L and Hex-F genes of M.domestica belong to two distinct multigenic ramifies. Our data support the assumption that Hex-F (and LSP2 from D.melanogaster) are hexamerins with a yet not well understood function in the vitellogenesis process.