Received: Accepted: AugPublished: October 4, 2018Ĭopyright: © 2018 Ohde et al. PLoS Genet 14(10):Įditor: Nicolas Gompel, Ludwig-Maximilians-Universitat Munchen, GERMANY (2018) Rhinoceros beetle horn development reveals deep parallels with dung beetles. Our findings highlight deep parallels in the development of rhinoceros and dung beetle horns, suggesting either that both horn types arose in the common ancestor of all scarabs, a surprising reconstruction of horn evolution that would mean the majority of scarab species (~35,000) actively repress horn growth, or that parallel origins of these extravagant structures resulted from repeated co-option of the same underlying developmental processes.Ĭitation: Ohde T, Morita S, Shigenobu S, Morita J, Mizutani T, Gotoh H, et al. Although our RNAi analyses reveal interesting differences in the functions of a few of these genes, the overwhelming conclusion is that both head and thoracic horns develop similarly in Trypoxylus and Onthophagus, originating in the same developmental regions and deploying similar portions of appendage patterning networks during their growth. These 11 genes are mostly categorized as larval head- and appendage-patterning genes that also are involved in Onthophagus horn formation, suggesting the same suite of genes was recruited in each lineage during horn evolution. Here we unveil 11 horn formation genes in a rhinoceros beetle, Trypoxylus dichotomus. However, current knowledge of the mechanisms underlying horn diversification remains limited to a single genus of dung beetles, Onthophagus.
Horns radiated prolifically and independently in two distant subfamilies of scarabs, the dung beetles (Scarabaeinae), and the rhinoceros beetles (Dynastinae). Beetle horns are attractive models for studying the evolution of novel traits, as they display diverse shapes, sizes, and numbers among closely related species within the family Scarabaeidae.