title: The function of Hox and appendage-patterning genes in the development of an evolutionary novelty, the Photuris firefly lantern.
abstract: Uncovering the mechanisms underlying the evolution of novel traits is a central challenge in biology. The lanterns of fireflies are complex traits that lack even remote homology to structures outside luminescent beetle families. Representing unambiguous novelties by the strictest definition, their developmental underpinnings may provide clues to their origin and offer insights into the mechanisms of innovation in developmental evolution. Lanterns develop within the context of abdominal Hox expression domains, and we hypothesized that lantern formation may be instructed in part by these highly conserved transcription factors. We show that transcript depletion of Abdominal-B in Photuris fireflies results in extensive disruption of the adult lantern, suggesting that the evolution of adult lanterns involved the acquisition of a novel regulatory role for this Hox gene. Using the same approach, we show that the Hox gene abdominal-A may control important secondary aspects of lantern development. Lastly, we hypothesized that lantern evolution may have involved the recruitment of dormant abdominal appendage-patterning domains; however, transcript depletion of two genes, Distal-less and dachshund, suggests that they do not contribute to lantern development. Our results suggest that complex novelties can arise within the confines of ancestral regulatory landscapes through acquisition of novel targets without compromising ancestral functions.
authors.affiliation: Center for Insect Science, University of Arizona, , 1007 East Lowell Street, PO Box 210106, Tucson, AZ 85721-0106, USA, Department of Biology, Indiana University, , 1001 East 3rd St., Jordan Hall 142, Bloomington, IN 47405-7005, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Stansbury
authors.forename: Armin P
authors.initials: AP
authors.lastname: Moczek
mesh_terms: D000818:Animals; D005075:Biological Evolution; D019521:Body Patterning / Q000235:genetics*; D048888:Fireflies / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development*; D005801:Genes, Homeobox; D017344:Genes, Insect; D034622:RNA Interference; D014157:Transcription Factors
chemical_list: D014157:Transcription Factors
keywords: Abdominal-B; Lampyridae; evo devo; photic organ