Striking parallels between dorsoventral patterning in Drosophila and Gryllus reveal a complex evolutionary history behind a model gene regulatory network

Dorsoventral pattering relies on Toll and BMP signalling in all insects studied so far, with variations the relative contributions of both pathways. Drosophila beetle Tribolium share extensive dependence Toll, while representatives more distantly related lineages like wasp Nasonia bug Oncopeltus rely strongly signalling. Here, we show that cricket Gryllus bimaculatus , an evolutionarily distant outgroup, has, a direct patterning role for ventral half embryo. In addition, polarises signalling, although this does not involve conserved inhibitor Sog/Chordin. Finally, activation ovarian mechanisms striking similarity to . Our data suggest two surprising hypotheses: (1) Toll's function is result convergent evolution or (2) Drosophila-like system arose early insect was extensively altered multiple independent lineages.