The overarching goal of this proposal is to the explore the role of stochastic gene expression during development and cell differentiation using the nematode worm Caenorhabditis elegans and mammalian cell lines as experimental model systems. In the first program of this proposal I describe a single molecule mRNA detection technique that allows accurate measurements of stochastic expression of endogenous genes in developmental and differentiation pathways. We will use this technique to determine expression fluctuations in the C. elegans endodermal specification pathway. Next, we will use this technology to better understand the phenomenon of incomplete penetrance. Many C. elegans mutants exhibit the phenomenon of incomplete penetrance, where only a certain fraction of genetically identical mutants exhibit the defective mutant phenotype, while the remaining organisms are often indistinguishable from the wild-type. We will test the hypothesis that these mutants allow stochastic events in the gene expression program controlling development to influence the organism's ultimate developmental outcome. Finally we will use the mRNA counting method to determine the stochastic component of mammalian cell fate decisions using the glucocorticoid pathway and hemapoietic progenitor cells as experimental model systems. The second program focuses on elucidating the roles of microRNAs in controlling gene expression fluctuations. During the last decade it has become clear that microRNAs play crucial roles in diverse biological processes including development and differentiation. Program 2 will explore the potential roles for microRNAs controlling gene expression fluctuations. First, we will experimentally determine the relationship between the concentration of a microRNA and its target in a single cell. Second, we will test the hypothesis that in order to dampen translational amplification of mRNA fluctuations, miRNAs may be employed to selectively lower the translation rate for genes that can fluctuate significantly. Finally, we will explore if microRNA-mediated feedback networks can lower fluctuations in target gene expression.

Agency
National Institute of Health (NIH)
Institute
Office of The Director, National Institutes of Health (OD)
Type
NIH Director’s Pioneer Award (NDPA) (DP1)
Project #
5DP1OD003936-03
Application #
7932055
Study Section
Special Emphasis Panel (ZGM1-NDPA-B (P2))
Program Officer
Jones, Warren
Project Start
2008-09-30
Project End
2013-07-31
Budget Start
2010-08-01
Budget End
2011-07-31
Support Year
3
Fiscal Year
2010
Total Cost
$840,000
Indirect Cost
Name
Massachusetts Institute of Technology
Department
Physics
Type
Schools of Arts and Sciences
DUNS #
001425594
City
Cambridge
State
MA
Country
United States
Zip Code
02139
Ramanan, Vyas; Trehan, Kartik; Ong, Mei-Lyn et al. (2016) Viral genome imaging of hepatitis C virus to probe heterogeneous viral infection and responses to antiviral therapies. Virology 494:236-47
Slavov, Nikolai; Budnik, Bogdan A; Schwab, David et al. (2014) Constant growth rate can be supported by decreasing energy flux and increasing aerobic glycolysis. Cell Rep 7:705-14
Bienko, Magda; Crosetto, Nicola; Teytelman, Leonid et al. (2013) A versatile genome-scale PCR-based pipeline for high-definition DNA FISH. Nat Methods 10:122-124
Tan, Rui Zhen; Ji, Ni; Mentink, Remco A et al. (2013) Deconvolving the roles of Wnt ligands and receptors in sensing and amplification. Mol Syst Biol 9:631
Neuert, Gregor; Munsky, Brian; Tan, Rui Zhen et al. (2013) Systematic identification of signal-activated stochastic gene regulation. Science 339:584-7
Bumgarner, Stacie L; Neuert, Gregor; Voight, Benjamin F et al. (2012) Single-cell analysis reveals that noncoding RNAs contribute to clonal heterogeneity by modulating transcription factor recruitment. Mol Cell 45:470-82
Buganim, Yosef; Faddah, Dina A; Cheng, Albert W et al. (2012) Single-cell expression analyses during cellular reprogramming reveal an early stochastic and a late hierarchic phase. Cell 150:1209-22
Slavov, Nikolai; Airoldi, Edoardo M; van Oudenaarden, Alexander et al. (2012) A conserved cell growth cycle can account for the environmental stress responses of divergent eukaryotes. Mol Biol Cell 23:1986-97
Munsky, Brian; Neuert, Gregor; van Oudenaarden, Alexander (2012) Using gene expression noise to understand gene regulation. Science 336:183-7
Itzkovitz, Shalev; Blat, Irene C; Jacks, Tyler et al. (2012) Optimality in the development of intestinal crypts. Cell 148:608-19

Showing the most recent 10 out of 23 publications