Ruvkun, Gary B.Shi, Zhen2013-10-152013-10-152013Shi, Zhen. 2013. Genetic and genomic analysis of small RNA pathways in nematodes. Doctoral dissertation, Harvard University.http://dissertations.umi.com/gsas.harvard:11093http://nrs.harvard.edu/urn-3:HUL.InstRepos:11169801Small noncoding RNAs, including microRNAs (miRNAs), piwi-interacting RNAs (piRNAs), and endogenous small-interfering RNAs (endo-siRNAs), regulate developmental and defense pathways in animals. While many small RNA silencing protein cofactors have been identified, much more is to be learned from a dynamic and quantitative perspective to reveal the underlying mechanisms and designing principles of each pathway. In this dissertation, I present studies that examine the temporal dynamics of small RNA pathways - one from an evolutionary time scale among the nematode species, and one from finely staged Caenorabditis elegans during the first larval stage. I also describe works identifying new cofactors functions in the miRNA pathway, potentially through regulating the spatial dynamics of the miRNA silencing complex.en-USGeneticsgeneticgenomicnematodessmall RNAThesis or Dissertation2013-10-15