Deciphering the molecular and neurogenetic mechanisms that modulate social behavior

Understanding how genetic and neurobiological processes interact to shape variation in social behavior is a central question in biology. Most laboratory systems lack natural variation in social structure, limiting our ability to study these processes. My lab addresses this gap by studying two complementary bee systems: socially variable sweat bees, where sociality has evolved independently multiple times, and the common eastern bumble bee (Bombus impatiens), which exhibits major shifts in colony organization throughout its life cycle. The social variability encompassed by bees provides a powerful foundation to experimentally dissect the factors that modulate social behavior and to test insights across independent lineages. To this end, my lab has developed a comprehensive toolkit to study these socially variable species, including: de novo, high-quality genome assemblies, tools for behavioral quantification, and methods for high-throughput genomics and neuroimaging. Because many of the core mechanisms that modulate behavior in insects and vertebrates are highly conserved, studies in bees can provide broader insights into the biological principles that shape behavior across a wide range of taxa. Our work has identified new ways in which early-life social environments and hormone signaling can shape social behavior. Over the next five years, we will focus on three main questions: (1) What genetic and neurobiological mechanisms modulate social interactions? We will examine a sensitive window for development of the bumble bee brain and social behavior to characterize the underlying mechanisms. This work will define the timing of this window and combine transcriptomic, neurogenomic, and behavioral studies with immediate early gene profiling to map neural responses to social stimuli. (2) How does hormone signaling regulate social behavior? Our comparative genomic work identified patterns of selection on the proteins that bind and transport the insect developmental hormone, juvenile hormone (JH), and revealed that JH can act directly on the brain. We will characterize the timing of JH signaling throughout adulthood and combine hormone manipulations with behavioral, transcriptional, and neurogenetic studies to understand how this developmental hormone has been repurposed to regulate social behaviors in adults. (3) What are the molecular signatures of social plasticity? Some sweat bee species are capable of producing both solitary and social nests even within the same population. We will use genome-wide association studies and transcriptomics to identify the genetic variants and neurogenetic pathways that underlie this social flexibility. My lab’s integrative approach combines genomics, neurobiology, and behavioral studies to gain a comprehensive understanding of how social behavior emerges from the dynamic interplay of genes, brains, and the environment. Discoveries from this work will help elucidate the fundamental building blocks of sociality, shedding light on how social behavior emerges and functions across diverse organisms. Project Number: 1R35GM161734-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of General Medical Sciences (NIGMS) | Principal Investigator: Sarah Kocher | Institution: PRINCETON UNIVERSITY, Princeton, NJ | Award Amount: $451,000 | Activity Code: R35 | Study Section: Special Emphasis Panel[ZRG1 MGG-F (55)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11260804