9603626 Moore Cell division in some form is central to reproduction of all organisms, and also to growth and reproduction of more complex forms of life. Regulation of this division is crucial, and loss of regulation has dire consequences for all forms of life. Because of this, extensive studies of the division process have been conducted and many aspects are increasingly well understood. One component of the process which has not been sufficiently studied is the control over membrane production. Membranes surround both the periphery and the cellular components, organelles, which specialize in specific metabolic functions of the cell. Production of too much, too little, or the wrong components of the membranes, or at the wrong time, would lead to aberrations in the daughter cells. The research would be devoted to measuring the changes in membrane composition which takes place during a cell division cycle and the biosynthetic/catabolic processes which accompany these changes. The photosynthetic organism, Chlamydomonas reinhardtti, will be utilized and the work will concentrate primarily on its major extraplastid membrane lipids, phosphatidylethanolamine and diacylglyceroltrimethylhomoserine. Since the pathways of synthesis of these two lipids are not defined for C. reinhardtti, determination of the pathways and intracellular locations of synthesis of these two lipids will receive initial priority. This project is concerned with regulation of synthesis of membranes, particularly their lipid components, in relation to cell division and the cell cycle. If membrane synthesis is not properly coordinated with cell division, serious problems could result. A simple alga, Chlamydomonas reinhardtii, that can be manipulated genetically will be studied. The pathway for synthesis of two major lipids will be analyzed and studied. This project will provide new information about how plants control their growth and reproduction and may have a long-term impact on crop production.
