Comparative transcriptomics suggests a highly species-specific nature of the phenotypic plasticity associated with the outbreaks of the two main pest locusts

The locust phase change phenomenon seems highly species-specific, very likely due to the inter-specific differences in the material used, and in the biology and life conditions of the different locust species. Research on locust outbreaks, gregariousness and swarming would therefore benefit from considering each locust species apart, and caution is needed when extrapolating results between species-as no species seems representative of all locust species. Still, the 109 genes and 39 non-annotated sequences that we found to change expression level the same way in the two main pest locusts, especially those previously reported as core transcriptional phase signature genes in L. migratoria's CNS-related tissues (10 and 1, respectively), provide material for functional testing in search for important genes to better understand, or to fight against locust outbreaks in a non-species-specific way. The large set of genes that respond in a species-specific way provide material for comparing, understanding and tackling the locust's phase change phenomenon in a species-specific way. The still uncharacterized transcripts that change expression either in a species-specific or the same way between the two species studied here provide material for gene discovery. Functional testing and confirmation are needed in all cases.