X-chromosome inactivation (XCI) is a dosage compensation epigenetic process that prevents a multiple X organism from imbalances within its genome. DNA’s interactions with histones modulate the accessibility of genetic material; during XCI, DNA is inactivated by methylation as histone tails are modified to prevent gene expression. The tendency of some X chromosomes to escape inactivation is hypothesized to influence rates of autoimmune diseases in multiple X organisms, as the genomic imbalance causes dysfunctionality. XCI and its maintenance function differently in immune cells, as evidenced by varying patterns of X inactivation specific transcript (Xist) RNA localization. The experiment aims to develop a mouse model by editing stem cells for insight into immune responses and how the escape phenomenon relates to immunity. Additionally, differences in expression between naïve and activated T and B cells will be examined by experimentally binding antibodies to CD28 and CD3 receptors. The X-linked genes–Rbm3, Was, and Pim2–were endogenously tagged with MS2 or PP7. CRISPR-mediated edits were used by which left and right homology arms of genomic DNA (gDNA) were matched. The donor vector was comprised of repeated MS2, or PP7, stem-loops, an antibiotic resistance gene, neomycin, and fragments of DNA that serve as a template for repairing DNA breaks. To repair, either a homology-directed repair or non-homologous end joining occurs at the site. The assay uses stem-loops formed by an MS2, or PP7, sequence and the coat protein of either bacteriophage as it is fused with a green, or red, fluorescent protein and reporter mRNA. The reporter mRNA consists of stem-loops bounded by the system. This technology forms the basis of collecting quantitative live imaging data and detecting/visualizing transcription dynamics and regulation with confocal microscopy. Colonies were genotyped (polymerase chain reaction whereby a section of DNA specific to the correctly edited cell is amplified) and ran through a gel electrophoresis machine to validate the existence of MS2, or PP7, and neomycin between gDNA strands. DTA, a toxin, and a control were also tested in the gel. If correct, cells were sent to Penn Vet to be grown; this is the current status of the experiment, and new data will be available in approximately six months. The cells will be injected into a mouse blastocyst so that all cells become genetically identical to the cells grown with edits. Once mice with MS2 and PP7 tagged genes are developed, they will cross to produce offspring with both MS2 and PP7 tagged. Genes in their immune cells will be imaged, and their receptors will experimentally bind to pathogenic infections. Expression of the specific X-linked gene that was tagged will be observed. Future research on gene silencing and immunity can be conducted using RNA interference (RNAi) or CRISPR interference pathways. To knock down Xist in immune cells, experiments will use siRNAs to target the transcription of specific genes and induce XCI/escape. Immune challenges will similarly be introduced.