Single-nuclei transcriptomes in the hypothalamus and POA of a highly social cichlid
How does complex behavior arise from the genome across biological levels? Specific cell types have evolutionarily conserved functional roles in regulating and maintaining various aspects of social behavior. There is a long history of research demonstrating how specific cells in the hypothalamus and POA are critical in regulating social status and reproductive behavior. This cell function is dependent not just on one gene, but the entire gene expression network working within each cell. The brain is a heterogenous tissue made up of a broad diversity of cells. Targeting the cellular-level transcriptomes in socially relevant brain regions enables the identification of social status mediators. Single-nuclei RNA-sequencing (snRNA-seq) provides the resolution to identify cell-specific transcriptomes, with more practical benefits compared to single-cell approaches. Single-nucleus sequencing of neuronal tissue has remained fairly limited to model mammalian organisms. Here we performed snRNA-seq in the hypothalamus and POA of Astatotilapia burtoni, a fish system ideal for social neuroscience. Male A. burtoni are characterized by plastic phenotypes associated with social status, dominant and subordinate, with well-established differences in neural gene expression patterns and specific neuron morphology. This provides a novel opportunity to apply snRNA-seq in a complex tissue of a non-model system using hypothesis driven approaches. We show how changes in social status are linked to distinct transcriptomic profiles at the cellular level.