Gryllus bimaculatus transcriptomic assembly

Transcriptome assembly from: <b><br></b><b>Striking parallels between dorsoventral patterning in <i>Drosophila</i> and <i>Gryllus</i> reveal a complex evolutionary history behind a model gene regulatory network</b><b><br></b><b>Pechmann et al, 2021<br></b><b><br></b> <b> </b> <b>Abstract</b> Dorsoventral pattering relies on Toll and BMP signalling in all insects studied so far, with variations in the relative contributions of both pathways. <i>Drosophila</i> and the beetle <i>Tribolium</i> share extensive dependence on Toll, while representatives of more distantly related lineages like the wasp <i>Nasonia</i> and bug<i> Oncopeltus</i> rely more strongly on BMP signalling. Here, we show that in the cricket <i>Gryllus bimaculatus</i>, an evolutionarily distant outgroup,<i> </i>Toll has, like in <i>Drosophila</i>, a direct patterning role for the ventral half of the embryo. In addition Toll polarizes BMP signalling, although this does not involve the conserved BMP inhibitor Sog/Chordin. Finally, Toll activation relies on ovarian patterning mechanisms with striking similarity to <i>Drosophila. </i>Our data suggest two surprising hypotheses: 1) that Toll’s patterning function in <i>Gryllus</i> and <i>Drosophila</i> is the result of convergent evolution or 2) a <i>Drosophila-like </i>system arose early in insect evolution, and was extensively altered in multiple independent lineages.<br>