Cricket genomes: The genomes of future food

Crickets are currently in focus as a possible source of animal protein for human consumption as an alternative to protein from vertebrate livestock. This practice could ease some of the challenges both of a worldwide growing population and of environmental issues. The two-spotted Mediterranean field cricket Gryllus bimaculatus has traditionally been consumed by humans in different parts of the world. Not only is this considered generally safe for human consumption, several studies also suggest that introducing crickets into one9s diet may confer multiple health benefits. Moreover, G. bimaculatus has been widely used as a laboratory research model for decades in multiple scientific fields including evolution, developmental biology, neurobiology, and regeneration. Here we report the sequencing, assembly and annotation of the G. bimaculatus genome, and the annotation of the genome of the Hawaiian cricket Laupala kohalensis. The comparison of these two cricket genomes with those of 14 additional insects supports the hypothesis that a relatively small ancestral insect genome expanded to large sizes in many hemimetabolous lineages due to transposable element activity. Based on the ratio of observed versus expected CpG sites (CpGo/e), we find higher conservation and stronger purifying selection of typically methylated genes than of non-methylated genes. Finally, our gene family expansion analysis reveals an expansion of the pickpocket class V gene family in the lineage leading to crickets, which we speculate might play a relevant role in cricket courtship behavior, including their characteristic chirping.