RESEARCH ARTICLE Variations on a Theme: Antennal Lobe Architecture across Coleoptera Martin Kollmann1, Rovenna Schmidt1,2, Carsten M. Heuer1,3, Joachim Schachtner1* 1 Department of BiologyÐAnimal Physiology, Philipps-University Marburg, Marburg, Germany, 2 Institute of Veterinary Anatomy, Histology and Embryology, Justus-Liebig University Gieûen, Gieûen, Germany, 3 Fraunhofer-Institut fuÈr Naturwissenschaftlich-Technische Trendanalysen INT, Euskirchen, Germany *
[email protected] a11111 Abstract Beetles comprise about 400,000 described species, nearly one third of all known animal species. The enormous success of the order Coleoptera is reflected by a rich diversity of life- styles, behaviors, morphological, and physiological adaptions. All these evolutionary adap- tions that have been driven by a variety of parameters over the last about 300 million years, OPEN ACCESS make the Coleoptera an ideal field to study the evolution of the brain on the interface Citation: Kollmann M, Schmidt R, Heuer CM, between the basic bauplan of the insect brain and the adaptions that occurred. In the current Schachtner J (2016) Variations on a Theme: study we concentrated on the paired antennal lobes (AL), the part of the brain that is typically Antennal Lobe Architecture across Coleoptera. PLoS ONE 11(12): e0166253. doi:10.1371/journal. responsible for the first processing of olfactory information collected from olfactory sensilla pone.0166253 on antenna and mouthparts. We analyzed 63 beetle species from 22 different families and