In addition, mutations in the death process may be responsible for some of the devastating effects of diseases such as cancer, AIDS and Alzheimer's. One of the earliest events in cell death is a loss of water which causes a cell to shrink. Water is known to cross membranes in one of two ways, either through simple osmosis or through newly discovered protein channels called aquaporins. My lab has been studying the role of aquaporins in mediating water loss during apoptosis and we have shown that cell shrinkage is accomplished by the efflux of water through these channels. Most importantly, functional aquaporins are required for cell death to occurr, suggesting they play a central role in controlling apoptosis.
Studies are underway to define exactly how aquaporins exert such a global effect on cell death.
As the egg matures it organizes a structure around itself called a follicle, containing an additional cell type know as a granulosa cell. The first stage consists entirely of an increase in the number of granulosa cells. In the second stage, cell proliferation ceases and a large fluid-filled sac, called an antrum, forms within the granulosa cell layer. Fluid continues to accumulate in the antrum until the follicle is ready to ovulate. Apoptotic nuclease assays.