A hemipteran insect reveals new genetic mechanisms and evolutionary insights into tracheal system development

Significance The emergence of a tracheal system for respiration is one of the landmarks of terrestrial adaptations among arthropods. Yet, this system is diverse in its organization and elusive in its origin. By studying tracheal development inOncopeltus fasciatus , we demonstrate the role of Hox genes in its morphogenesis and distinct segmental patterning. Furthermore, we report that the exocrine glands expressventral veinless and are under the regulation of Hox genes, similar to the endocrine glands and the trachea. This discovery highlights how a shared gene network could have regulated the development of these structures in a common insect–crustacean ancestor.