Our research uses single-nucleus multiomic approaches to understand cellular diversity and gene regulation in Daphnia. We apply single-nucleus RNA sequencing (snRNA-seq) and single-nucleus ATAC sequencing (snATAC-seq) to characterize gene expression and chromatin accessibility across different cell populations. Current work includes comparing wild-type and mutant animals to examine how genetic changes influence cellular states under normal growth conditions. We are also optimizing nuclei isolation, microscopy-based quality control, sequencing workflows, and computational methods for cell-type identification and multiomic data integration. By connecting transcriptional activity with accessible regulatory regions, this research aims to build a cell-level molecular atlas of Daphnia and identify biological pathways associated with development, environmental responses, and organismal phenotypes. This platform will support broader studies of functional genomics, chromatin regulation, and evolutionary biology in Daphnia.