Beetle thoracic horns share a developmental origin with wings
Understanding how complex novel traits has been a challenge to biologists for as long as evolutionary biology has existed as a field of study. Recently researchers at Indiana University investigated the origin of prothoracic horns in scarabaeine beetles, one of the most pronounced
examples of secondary sexual traits in the animal kingdom.
The team, which comprised of Yonggang Hu, David M. Linz, and Armin P. Moczek, demonstrated that prothoracic horns derive from bilateral source tissues; that diverse wing genes are functionally required for instructing this process; and that, in the absence of Hox input, prothoracic horn primordia transform to contribute to ectopic wings. Once induced, however, the transcriptional profile of prothoracic horns diverges markedly from that of wings and other wing serial homologs. The results substantiate the serial homology between prothoracic horns and insects wings and suggest that other insect innovations may derive similarly from wing serial homologs and the concomitant establishment of structurespecific transcriptional landscapes.