The recent construction of brain-wide gene expression atlases, which measure the transcriptional activity of thousands of genes in many different anatomical locations, has made it possible to connect spatial variations in gene expression to distributed properties of connectome structure and function. These analyses have revealed that spatial patterning of gene expression and neuronal connectivity are closely linked, following broad spatial gradients that track regional variations in microcircuitry, inter-regional connectivity and functional specialization. Superimposed on these gradients are more specific associations between gene expression and connectome topology that appear conserved across diverse species and resolution scales. These findings highlight the utility of brain-wide gene expression atlases for bridging the gap between molecular function and large-scale connectome organization in health and disease