Characterization of hormone-producing cell types in the medaka pituitary gland using single-cell RNA-seq

The pituitary is the vertebrate endocrine gland responsible for the production and secretion of several essential peptide hormones. These, in turn, control many aspects of an animal's physiology and development, including growth, reproduction, homeostasis, metabolism and stress responses. In teleost fish, each hormone is presumably produced by a specific cell type. However, key details on the regulation of, and communication between these cell types are still poorly understood. We have therefore generated gene expression profiles for 2592 and 3804 individual cells from the pituitaries of female and male adult medaka (Oryzias latipes), respectively. Based on expression profile clustering, we define 15 and 16 distinct cell types in the female and male pituitary, respectively, of which nine are involved in the exclusive production of a single peptide hormone. Collectively, our data provide a high-quality reference for studies on pituitary biology and the regulation of hormone production, both in fish and in vertebrates in general. Overall design: Single cell sequencing (scRNA-seq) of the medaka pituitary.