Understanding the development and function of a newly discovered intestinal cell type

(See instructions): The long-term goal of this project is to characterize the transcriptional regulation underlying development and understand function of a newly discovered intestinal cell type called best4+ cells, that is depleted in inflammatory bowel disease patients, It is however unresolved whether best4+ cell loss causes disease or whether disease kills best4+ cells, Improper differentiation of intestinal cells often leads to loss of specialized functions that manifest in disease, Since it is not well understood how best4+ cells contribute to intestinal homeostasis and how their dysfunction leads to disease, this proposal also focuses on understanding the function of best4+ cells, The function of best4+ cells remain largely unknown in any organism; however, previous single-cell profiling predicted some physiological roles such as pH sensing, electrolyte homeostasis, and regulation of satiety, Since best4+ cells are absent from mouse models, experiments will ablate best4+ cells in the zebrafish intestine and study the response of other intestinal cell types using single-cell RNA sequencing as well as measure disease hallmarks in the intestine (pH changes, epithelial barrier loss, inflammation etc,), Furthermore, factors predicted from single-cell RNAseq studies will be perturbed to understand the roles of each of these genes in regulating overall best4+ cell function, To test the alternate hypothesis whether best4+ cell loss is a symptom of disease rather than cause, this proposal will also induce inflammation in the zebrafish intestine in the presence and absence of best4+ cells to characterize how various intestinal cells including best4+ cells respond to changes in the intestinal environment and what aspects of the overall intestinal response to disease is regulated by best4+ cells. Project Number: 4R00HD115786-02 | Fiscal Year: 2026 | NIH Institute/Center: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) | Principal Investigator: Abhinav Sur | Institution: UNIVERSITY OF ARIZONA, TUCSON, AZ | Award Amount: $249,000 | Activity Code: R00 | Study Section: NSS View on NIH RePORTER: https://reporter.nih.gov/project-details/11505172