Abstract
The biological function of a gene often depends on spatial context, and an atlas of transcriptional regulation could be instrumental in defining functional elements across the genome. Despite recent advances in single-cell RNA sequencing and in situ RNA imaging, fundamental barriers limit the speed, genome-wide coverage, and resolution of de novo transcriptome assembly in space. Here, I discuss potential next-generation approaches for the de novo assembly of the transcriptome in space, and propose more efficient methods of detecting long-range spatial variations in gene expression. Finally, I discuss future in situ sequencing chemistries for visualizing biological pathways and processes in tissues so that genomics technologies might be more easily applied to conditions of human health and disease.