Analyzing the formation of germline cyst - A critical cellular organization in early oogenesis

In gametogenesis, germ cells organize in a cellular hub called the germline cyst, which is common to both sexes and is conserved from insects to mammals. In oogenesis, the cyst forms by incomplete cytokinesis of mitotic oocyte precursors called oogonia, resulting in interconnected germ cells clustered compactly and surrounded by somatic cells. Differentiating oocytes continue to develop within the cyst, before leaving it to form the primordial follicle. The cyst serves as a hub for key events in early oogenesis, which in humans occur in the developing prenatal ovary, and by birth determine the number and quality of oocytes for the entire female life span. However, while the cyst has been extensively characterized in Drosophila, its formation and function in vertebrates, including mammals, remain unclear. We present a deep learning-based high throughput analysis pipeline combining in-situ imaging and high-resolution live imaging microscopy. Through our analysis, we will uncover the cyst cell division pattern and features such as cyst cells` connectivity and spatial arrangement in vivo. In addition to these, we expand our analysis, in-vivo modulating the various cellular components to analyze their effect on germline cyst development and maintenance utilizing high-resolution real-time live imagining. These methods will pave the way for investigating the cyst cellular organization. Our findings will expand the toolkit for analyzing early oogenesis in zebrafish and shed new light on its underlying cell and developmental biology.