To Study the Connection between Lipid Metabolism Related Gene and Germ Line Development in C. elegans

Germ cell development is an energy spending process to keep organism alive. Unsaturated fatty acid (UFA) is an important resource for both membrane composition and energy support in organisms. However, knowledge of germ cell development remains limited. For example, PubMed contains 37281 papers related to “germ cell development”, but among them fewer than 310 papers related to UFA and only 3 articles used C. elegans as an animal model. In this regard, my proposal has made advances in the following aspects: 1. C elegans is a very unique animal model to study the roles of UFA in germ cell development. 2. C. elegans is easy and inexpensive to be maintained in laboratory, and simple to get mutant strain and perform RNA knockdown analysis, and easy to examine by microscope. 3. We apply a novel biophotonic tool (Coherent Anti-stoke Raman Scattering microscopy) to study UFA metabolism in live C. elegans in noninvasive way and without any labeling (Yi et al., 2014). We demonstrated the UFA biosynthesis mutation (fat-1~7) caused sperm number decrease and germ line development defect in C. elegans. It suggested the germ line development is related to UFA biosynthesis. For further study the detail mechanisms, I will apply DNA staining and fluorescence microscopy techniques to compare the changes in nucleus number from different developmental stage in germ line between wild type and fat-1~7 mutants (first year). In the same period, I will apply the oxygen consumption rate analysis, ATP production measurement and gonad mitochondrial activity assay to further investigate the relationship between UFA biosynthesis genes (fat-1~7) and germ cell development. In our preliminary data, we found that the rRNA biosynthesis mutated worms (dao-5 and fib-1) cause dramatically decrease in the amount of lipid droplets/long-chain unsaturated fatty acid and down regulate genes expression in fatty acid biosynthesis, metabolism, and transportation. So in the second year, I plan to address the relationship between rRNA biosynthesis and germ cell development by using all analysis platforms established in the first year. In the third year, I plan to apply RNAi screening and mutation strains to screen the fatty acid biosynthesis related gene/pathway (such as autophage pathway and rapamycin (TOR) pathway) and further study the functions in germ cell development by using the well established experiment platforms show above. By the end of project, I hope we will reveal at least three genes/pathways involving in both fatty acid metabolism and germ cell development, and the obtained results can be extended to human germ cell development and fatty acid metabolism.

Project ID:PA10501-1131
External Project ID:MOST103-2321-B182-013-MY3