In a groundbreaking study published in PLOS Biology, researchers from the University of Illinois at Urbana-Champaign have uncovered remarkable genetic parallels underpinning social behavior in both honey bees and humans. This discovery sheds light on the ancient molecular roots of sociability, suggesting evolutionary conservation of social mechanisms across species separated by more than 600 million years. The work, led by Ian Traniello and colleagues, harnesses cutting-edge genomic sequencing, brain transcriptomics, and automated behavioral tracking technologies to unveil the complex genetic architecture of social interactions in the western honey bee (Apis mellifera).
Understanding sociability—the degree to which individuals engage and form connections within their social groups—has long posed a challenge for biologists. In many species, which include both insects and mammals, individuals exhibit considerable variation in how socially interactive they are. This variation is influenced by multiple factors including environmental stress, developmental history, neural states, and genetics. However, pinpointing the specific genes and molecular pathways that govern these behaviors has remained elusive, particularly in non-mammalian species. The current research represents a key advance, illuminating some of the conserved genetic mechanisms that shape sociality across distant branches of the evolutionary tree.
The team employed a novel approach by integrating genome-wide analyses with behavioral data from entire honey bee colonies. Using specialized miniaturized barcodes attached to hundreds of individual bees, the scientists tracked the social interactions of these insects in custom-built glass observation hives. This automated monitoring system recorded thousands of trophallaxis events—a behavior where bees share nutritious liquid food mouth-to-mouth, serving both to nourish nestmates and to reinforce social bonds. By correlating this detailed behavioral data with whole-genome sequencing results collected from 357 bees, the researchers identified 18 genetic variants significantly related to the propensity to engage in food-sharing behaviors.
Among these important loci, variants within two key genes—neuroligin-2 and nmdar2—stood out. Both of these genes encode synaptic proteins involved in neuronal communication. Intriguingly, their human orthologs have been implicated in autism spectrum disorders, a set of neurodevelopmental conditions characterized by altered social interactions. The researchers hypothesize that these conserved genes may contribute to fundamental aspects of social cognition across diverse species, despite the stark differences between insect and human nervous systems.
Further insight was gained through transcriptome sequencing of bee brains engaged at differing levels in social interaction. Over 900 genes showed increased expression levels in bees that more frequently engaged in trophallaxis compared to less social individuals. This expansive gene expression signature hints at a widespread molecular network supporting social behaviors, likely encompassing neurotransmission, synaptic plasticity, and metabolic adaptations essential for complex group living. The identification of such a broad gene set reinforces the idea that sociability is polygenic and multifaceted, involving numerous pathways and cellular processes.
What makes these findings especially compelling is the deep evolutionary conservation suggested by this work. Despite the divergence between the lineages leading to bees and humans dating back over half a billion years, there appear to be ancient genetic “building blocks” that have been preserved to support social behaviors. Whether due to convergent evolution or retained ancestral functions, the data reveal shared molecular frameworks enabling social engagement that extend far beyond the traditionally studied mammalian models.
Traniello and his colleagues emphasize that social insects like honey bees offer an unparalleled system for studying sociogenomics at scale. The colony organization of bees allows continuous monitoring of individual experiences and interactions throughout their entire adult lives—an advantage rarely available in vertebrate studies. The coupling of advanced molecular techniques with precise behavioral assays represents a new frontier in behavioral genetics, one that promises to unravel the biological architecture of sociality with unprecedented resolution.
Moreover, the methodological synergy in this study—combining behavioral tracking, whole-genome and RNA sequencing—exemplifies the power of integrative research to penetrate complex biological phenomena. By precisely linking genetic variation to expression changes to observed behavior within the same individuals, the team achieved a multidimensional profile unattainable by traditional approaches. This paradigm illustrates how high-throughput molecular data can be harnessed to address fundamental questions in neuroscience, ethology, and evolutionary biology.
The implications of the study stretch beyond the world of bees, offering important perspectives on human social disorders. Since genes like neuroligin-2 and nmdar2 are associated with autism, these findings suggest ancient genetic components may influence social behavior and its dysfunction across species. Understanding these conserved mechanisms might ultimately pave the way for innovative interventions or therapies targeting social cognitive impairments by illuminating their foundational molecular nature.
At its core, this research also speaks to the universality of social life. Sociability—defined by a spectrum ranging from highly interactive to more isolated individuals—pervades animal societies, shaping survival, reproduction, and group cohesion. The discovery that this variability has deep evolutionary roots highlights the importance of genetic diversity in social traits and invites reconsideration of social behavior as a trait shaped by powerful selective forces operating over hundreds of millions of years.
Ian Traniello remarks on the significance of their approach: “We can follow all these animals throughout most of their lives, identify who interacts with whom, and link these interactions to genomic structure and brain gene expression patterns. By bringing these technologies together, we can test the hypothesis that molecular features underlying social organization might be conserved across species, and indeed our results confirm this fascinating possibility.”
The study sets a new standard for behavioral genomics research and opens exciting avenues for future work. Further analyses might investigate how environmental factors modulate the expression of these conserved genes, or how different social contexts influence molecular pathways contributing to sociability. Additionally, comparative studies across other insect species or vertebrates could reveal the extent of these ancient social molecular frameworks and their evolutionary modifications.
In conclusion, the integration of behavioral data with genomic and transcriptomic analyses in honey bees provides compelling evidence for shared genetic foundations of social behavior across widely divergent species. This convergence of technological innovation and evolutionary insight redefines our understanding of sociability as a deeply rooted, complex, and conserved biological trait, bridging the gap between insect and human social neuroscience.
Subject of Research: Animals
Article Title: Genetic variation influences food-sharing sociability in honey bees
News Publication Date: September 16, 2025
Web References: http://dx.doi.org/10.1371/journal.pbio.3003367
References:
Traniello IM, Avalos A, Gachomba MJM, Gernat T, Chen Z, Cash-Ahmed AC, et al. (2025) Genetic variation influences food-sharing sociability in honey bees. PLOS Biol 23(9): e3003367. https://doi.org/10.1371/journal.pbio.3003367
Image Credits: Dr. Zachary Huang (CC-BY 4.0)
Keywords: Honey bees, sociability, genetics, neurogenomics, trophallaxis, Apis mellifera, social behavior, autism-related genes, neuroligin-2, nmdar2, transcriptomics, evolutionary biology
