Novel food safety by the analysis of T. molitor tropomyosin sequence and expression

Insects are increasingly considered a commonly acceptable food source for both human beings and domestic livestock in industrial countries. Economical attention on insects as a protein source is due to their high nutritional value but also to the escalating conventional cost of protein sources such as meat, fish meal and soybean meal. Furthermore, the consumption of insects as a protein source has a lower environmental impact than the protein source of vertebrates.

Tenebrio molitor belongs to the Tenebrionidae family of the Coleoptera order. Recently, the EFSA released a scientific opinion on the safety of dried yellow mealworm (T. molitor larva) considering the uses of the whole, dried mealworms as snack products and ground, powdered mealworms in various other food products (e.g. baked goods, energy bars, pasta).

Among food allergens, crustaceans, such as shrimp, crab, crawfish and lobster, are a frequent cause of adverse food reactions in allergic individuals. The major allergen has been identified as the muscle protein tropomyosin. This molecule belongs to a family of highly conserved proteins with multiple isoforms found in both muscle and nonmuscle cells of all species of vertebrates and invertebrates. Allergenic tropomyosins are found in invertebrates such as crustaceans (shrimp, lobster, crab, crawfish), arachnids (house dust mites), insects (cockroaches), and mollusks (e.g. squid), whereas vertebrate tropomyosins are nonallergenic.

The research will involve different activities as reported below:

• T. molitor Tropomyosin_1 gene sequence is currently not available. The first activity will be realized to proceed with the design of primer pairs on phylogenetically related species to reconstruct the gene sequence. 
• The second activity will be the reconstruction of the gene sequence by amplification of DNA fragments, overlapping sequences, cloning of fragments and finally the gene sequence obtainment.
• On the obtained sequence, primers for gene expression analysis will be developed. 
• The whole RNA extracted from the T. molitor larvae, after reverse transcription, will be analysed using RT-PCR to evaluate the differential gene expression in different growth conditions.

• The main result is to obtain T. molitor Tropomyosin_1 gene sequence. 
• The second results is to evaluate the differential gene expression in different growth conditions of T. molitor larvae.
• The third results is to identify specific conditions to reduce the gene expression and consequentely the allergenic impact.