2024 AIChE Annual Meeting
Quantitative Understanding of Pmad at Different Stages of Cell Division in Germline Stem Cells
Stem cell decision making is not fully understood, which makes the use of stem cell therapy inconsistent. More research in understanding the pathways by which stem cells differentiate can provide better control on determining the outcome. A key part of this understanding is the Bone Morphogenetic Protein (BMP) Pathway, which is a major biological signaling pathway that plays a part in stem cell decision making. In particular, the BMP pathway occurs in the ovaries of fruit flies, where germline stem cells divide into differentiated cells called the cystoblast. Dpp, the main ligand in the fruit fly BMP pathway, is secreted by the cap cells, which are adjacent to the germline stem cell. Secreted Dpp then forms an extracellular diffusion gradient that extends to the end of the germline stem cell. Dpp activates receptors on the surface of the stem cells resulting in the phosphorylation of the protein Mad. Phospho-Mad (pMad) binds with protein Medea (Med) and acts as a transcription factor in the nucleus of the cell, downregulating bam, the factor that causes differentiation in germline stem cells. Despite its central role in regulating differentiation, there is no quantitative measure of pMad in relation to stem cell differentiation/self-renewal, especially at different stages of cell division. Having a quantitative understanding of this system would improve the efficiency and reliability in stem cell therapy. The goal of this project is to document how pMad changes at different stages of cell division. This goal will be achieved by performing ovary dissections and immunostaining to preserve the spatial and concentration of proteins of interest. The results of this project would be a collection of pMad concentrations in the germline stem cell and cystoblast at different stages of division. The results can be analyzed to begin to understand the role pMad has in making the stem cell decision making distinct to either differentiation or self-renewal.