Meeting Abstract
13.3 Tuesday, Jan. 4 Developmental Genetics and Evolution of Flour Beetle (Tribolium) Antennal Morphology SMITH, F.W.*; ANGELINI, D.R. ; JOCKUSCH, E.L.; University of Connecticut; American University; University of Connecticut frank.smith@uconn.edu
A prominent issue in the field of evolutionary developmental biology is elucidating the developmental underpinnings of morphological differences between species. Flour beetles (Tenebrionidae), including Tribolium castaneum, T. confusum, T. brevicornis, and Latheticus oryzae provide an excellent system to begin to address this issue, due to the resolved relationships among these species and variation in antennal morphology. The antennal flagellum of these species consists of nine articles divided into a proximal funicle and more robust distal club. Here, a candidate gene approach was adopted to elucidate the developmental underpinnings of the transition from the ancestral antennal state consisting of five club articles and four funicle articles (T. confusum, T. brevicornis, and L. oryzae) to an antenna consisting of three club articles (T. castaneum) and six funicle articles. Previous work in T. castaneum identified three transcription factors required for normal patterning of the distal two funicle articles. Since these articles exhibit club identity in the other species, RNA interference (RNAi) experiments were used to characterize the function of these genes in the other species. RNAi against homothorax resulted in loss and fusion of articles of the proximal and mid antennal domains in all species studied and a transformation of the proximal antennal domain towards leg identity in T. confusum and T. brevicornis. RNAi against dachshund resulted in loss and fusion of articles of the mid antennal domain in all species studied, and a transformation of funicle articles toward club identity in T. castaneum and T. confusum. RNAi against drumstick resulted in loss and fusion of articles of the proximal and mid antennal domains in all species studied. The significance of these results for the evolution of antennal morphology will be discussed.
