UC San Diego

How a biological system copes with its intrinsic noise and extrinsic noise has become a major question in the field of quantitative biology. In particular, developmental and evolutionary consequences of gene expression noise has merged as an active area of study in the last few years. Many genetic network motifs and molecular mechanisms have been found to tune or control gene expression variation in different biological systems. Some of the pioneer studies in quantitative biology have discovered regulatory network motifs critical to developmental processes. How gene expression variation leads to phenotypic variation and how phenotypic variation can lead to improved species fitness. To date, few studies have focused on how gene expression variation leads to phenotypic variation in developmental processes. In our study, a quantitative method, single-molecule FISH, is coupled with mathematical modeling to examine how gene expression variation can be propagated through the C. elegans intestinal development network and how gene expression variation during developmental processes translate into phenotypic variation.

This quantitative approach has been applied to other Caenorhabiditis species. Differences in expression profiles of orthologous genes in the intestinal development network were observed. Taken in the context of a partially conserved network topology, expression differences were added to the model and yielded insights into mechanisms behind developmental decision making in formation of intestines in C. briggsae and C. remanei.