Common genetic toolkit shapes horns in scarab beetles

Rhinoceros beetles and dung beetles use the same genes to form their elaborate horns

Date:  October 4, 2018

Source:  PLOS

Horns have evolved independently multiple times in scarab beetles, but distantly related species have made use of the same genetic toolkit to grow these prominent structures, according to a study publishing October 4, 2018 in the open-access journal PLOS Genetics by Teruyuki Niimi at the National Institute for Basic Biology in Okazaki, Japan, and colleagues.

There are over 35,000 species of scarab beetle (Scarabaeidae), and many scarab beetles grow horns on the head and/or upper body. Horns are considered to be independent radiation in rhinoceros beetles and their distant relatives dung beetles. Rhinoceros beetles include some of the largest insect species on earth, such as the famous Atlas and Hercules beetles. To investigate the genetic mechanisms that control horn development in these distant groups, the team examined gene expression and function in early horn cells in developing larvae of the Japanese rhinoceros beetle (Trypoxylus dichotomus), and compared this with published data for dung beetles.

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