Leveraging Forward Genetics to Elucidate Membrane and Lipid Homeostasis

Since 2001, my lab has used forward genetics to isolate novel interesting mutants in C. elegans, with a particular focus on identifying the genes responsible for lipid homeostasis. Using this approach, we identified well over 50 novel alleles in over 20 genes and were able to define molecular pathways that protect cell membrane composition against environmental or dietary insults, or that compensate for a reduced ability to produce polyunsaturated fatty acids, or that regulate the trafficking of cellular material essential to maintain the structural boundaries that surround cells. Basically, our go-to approach is this: 1) Think of a cool new screen; 2) Randomly mutagenize worms with a mutagen (EMS) and screen preferably until >10 novel mutants are found; 3) Outcross the mutants 6 times to “clean up their genome”; 4) Do whole genome sequencing (WGS) to identify candidate mutations that caused the phenotype of interest; 5) Experimentally confirm the causative mutant alleles using CRISPR/Cas9 to re-create them; 6) Characterize the novel alleles and try to elucidate the pathway involved. This is a super powerful and unbiased experimental approach: we let the worms tell us what genes are responsible for the biological phenomenon we are interested in!