Gene Loss and Ecological Adaptation in Honeybee Venom: Exploring the Absence of Melittin in Apis andreniformis

Gene Loss and Ecological Adaptation in Honeybee Venom: Exploring the Absence of Melittin in Apis andreniformis

Alvin Sherman Library

Genetic divergence within the Apis honeybee genus is shaped by geography, climate, and ecological specialization, leading to variations in morphology, behavior, and venom composition. Comparative genomic analyses have revealed both gene loss and lineage-specific adaptations that contribute to these traits. In this study, we investigate the evolutionary, molecular, and biochemical factors influencing venom production across honeybee species, with a focus on the unexpected absence of a detectable melittin gene in Apis andreniformis (Black Dwarf Honeybee). While melittin constitutes 40-60% of the venom in Apis mellifera, BLAST searches failed to identify a homolog in A. andreniformis, despite its venom displaying comparable toxicity. This absence may be due to the divergence of melittin, preventing detection of a highly diverged homolog. Drawing on existing venom transcriptomics and comparative studies, we explore alternative pathways for venom production in the absence of melittin. By examining the evolution venom components such as melittin and phospholipase A2, we trace their origins to the Triassic period, inherited from common ancestors of the Symphyta. Our comparison of A. andreniformis with A. mellifera, A. cerana, and A. florea highlights the role of environmental and ecological factors in venom diversification. These findings demonstrate how gene loss, gene divergence, functional redundancy, and ecological pressures influence venom evolution within Apis, offering insights into the potential for discovering novel bioactive peptides with therapeutic applications.