The germline stem cell niche in the Drosophila ovary is one of the few niches that have been well described with reference to factors that maintain viability and stem cell potential. How cells exit the niche to begin their differentiation path has also been characterized, and the somatic follicle stem cells and their niche are being actively investigated. Dr. Spradling’s lab has led this field. His address will describe the types of factors and processes that establish and maintain niches, and will provide an example of the types of things we’d like to know about niches generally.

The purpose of this session is to describe current knowledge of stem cell or other cellular niches in tissues of interest: Where are stem cells within a tissue? What cells surround them? What extracellular cues are produced by the surrounding cells to maintain viability and pluripotency of stem/progenitor cells? How do niches regulate cell function and behavior?

This session will describe how niches change following disease, injury, or aging: How do otherwise quiescent stem/progenitor cells become “activated” to repair tissue? How does inappropriate regulation of stem cells result in disease or degeneration?

Speakers in this session will describe factors that define particular niches during embryonic development. What factors define the site at which organogenesis will occur and what maintains the viability and continued development of the organ?

This session will focus on studies of manipulations that facilitate viability and function of transplanted stem cells or other cells. What extracellular matrices are required to maintain function? Growth factors? Do therapeutic niches recapitulate developmental niches?