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SUMMARY:A quantitative view of gene expression levels in the T helper cell
  system - Dr Sarah Teichmann\, Laboratory of Molecular Biology
DTSTART:20120516T113000Z
DTEND:20120516T123000Z
UID:TALK37359@talks.cam.ac.uk
CONTACT:Sue Griffin
DESCRIPTION:Gene expression levels are believed to be continuously distrib
 uted from very low to very high levels\, with most genes at an intermediat
 e level. We have studied the transcriptome-wide distribution of expression
  levels in mouse T helper cells using RNA-seq technology\, and have develo
 ped a variety of ways to model the expected background levels. This is cri
 tical for definition of a threshold level of expression of a gene in a giv
 en cell type. In order to calibrate the RNA-seq expression levels in terms
  of molecules of mRNA per cell\, we have integrated the RNA-seq data with 
 single molecule mRNA-FISH experiments. \n\nThe results of these analyses a
 nd experiments show that many genes are expressed at > ~ 1 molecule per ce
 ll and that two major expression levels can be identified which vary by ro
 ughly one to two orders of magnitude. This gives rise to bimodal distribut
 ions of gene expression levels in cell populations. Analysis of histone mo
 difications by ChIP-seq indicates that activating modifications such as H3
 K9/14ac and H3K4me3 are involved in this ‘digital’ expression switch. 
 \n\nOur findings have broad implications for the analysis RNA-seq and ChIP
 -seq data and for the understanding of the regulation of gene expression.\
 n\nReferences\n\nHebenstreit\, D.\, Fang\, M.\, Gu\, M. Charoensawan\, V.\
 , van Oudenaarden\, A. & Teichmann\, S.A. (2011) RNA sequencing reveals tw
 o major classes of gene expression levels in metazoan cells. Mol. Sys. Bio
 l.\, 7:497.\n\nHebenstreit\, D.\, Gu\, M.\, Haider\, S.\, Turner\, D.\, Li
 o\, P. & Teichmann S.A. (2011) EpiChIP: gene-by-gene quantification of epi
 genetic modification levels. Nucleic Acids Res.\, 39\, e27\n\nHebenstreit\
 , D.\, Deonarine\, A.\, Babu\, M.M. & Teichmann\, S.A. (2012) Duel of the 
 fates: the role of transcriptional circuits and noise in CD4+ cells. Curr 
 Op Cell Biol.\, in press.\n
LOCATION:Lecture Theatre\, Department of Pathology\, Tennis Court Road
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