1,089 research outputs found
Caracterização da arquitetura de planta em genótipos de algodoeiros portadores do carater "CLUSTER" e normal em diferentes espaçamentos.
Get PDFEpigenetic Chromatin Silencing: Bistability and Front Propagation
Full text linkThe role of post-translational modification of histones in eukaryotic gene
regulation is well recognized. Epigenetic silencing of genes via heritable
chromatin modifications plays a major role in cell fate specification in higher
organisms. We formulate a coarse-grained model of chromatin silencing in yeast
and study the conditions under which the system becomes bistable, allowing for
different epigenetic states. We also study the dynamics of the boundary between
the two locally stable states of chromatin: silenced and unsilenced. The model
could be of use in guiding the discussion on chromatin silencing in general. In
the context of silencing in budding yeast, it helps us understand the phenotype
of various mutants, some of which may be non-trivial to see without the help of
a mathematical model. One such example is a mutation that reduces the rate of
background acetylation of particular histone side-chains that competes with the
deacetylation by Sir2p. The resulting negative feedback due to a Sir protein
depletion effect gives rise to interesting counter-intuitive consequences. Our
mathematical analysis brings forth the different dynamical behaviors possible
within the same molecular model and guides the formulation of more refined
hypotheses that could be addressed experimentally.Comment: 19 pages, 5 figure
Plasma Physics
Get PDFContains reports on six research projects.United States Atomic Energy Commission (Contract AT(30-1)-1842
Plasma Physics
Get PDFContains research objectives and reports on three research projects.U. S. Atomic Energy Commission under Contract AT(30-1)-1842National Science Foundation (Grant G-9330)U.S. Air Force (Electronic Systems Division) under Contract AF19(604)-599
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