Diptera Bicoid Evolution - Mulhair et al

This study analyses the emergence and evolution of the <i>bicoid</i> gene in Diptera. We uncover a non-cyclorrhaphan origin for <i>bicoid</i> and describe high rates of gene loss. To determine if the non-cyclorrhaphan <i>bicoid</i> mRNA is also localised to the anterior region of the developing embryo, as in <i>Drosophila</i>, we carried out <i>in situ</i> hybridisation using the dark edged bee fly <i>Bombylius major</i>, finding that it is functionaly as well as evolutionarily homologous to <i>bicoid</i> in Cyclorrhapha<i>.</i><i> </i>In order to confidently place the point of origin we revisit the dipteran species phylogeny, with a particular focus on the early Brachycera branching patterns. Finally, we reconstruct the ancestral zen and bcd homeodomain sequences to assess how these newly found non-cyclorrhaphan <i>bicoid</i><i> </i>sequences impact our understanding of the order and contribution of amino acid substitutions which gave <i>bicoid</i> is novel function.<br><br>All major data and code used in this study are available on this figshare repository. If there are any queries about any of the files please do not hesitate to contact any of the authors.