"Regulation of MicroRNA Expression and Abundance during Lymphopoiesis" AND "MicroRNA evolution by arm switching"

Paper #1: Immunity, Paper #2: EMBO reports
Authors
Paper #1:
Stefan Kuchen,1,10 Wolfgang Resch,1,10,* Arito Yamane,1,10 Nan Kuo,1 Zhiyu Li,1 Tirtha Chakraborty,2 Lai Wei,3, Arian Laurence,3 Tomoharu Yasuda,2 Siying Peng,2 Jane Hu-Li,4 Kristina Lu,5 Wendy Dubois,6 Yoshiaki Kitamura,7, Nicolas Charles,7 Hong-wei Sun,8 Stefan Muljo,4 Pamela L. Schwartzberg,5 William E. Paul,4 John O’Shea,3, Klaus Rajewsky,2 and Rafael Casellas1,9,*


Paper #2:
Griffiths-Jones S, Hui JH, Marco A, Ronshaugen M.
05-09-2011
12:00pm
PST
Categories
RNA Synthetic Biology & Systems Biology
Speaker
Abstract
Although the cellular concentration of miRNAs is critical to their function, how miRNA expression and abundance are regulated during ontogeny is unclear. We applied miRNA-, mRNA-, and ChIP-Seq to characterize the microRNome during lymphopoiesis within the context of the transcriptome and epigenome. We show that lymphocyte-specific miRNAs are either tightly controlled by polycomb groupmediated H3K27me3 or maintained in a semi-activated epigenetic state prior to full expression. Because of miRNA biogenesis, the cellular concentration of mature miRNAs does not typically reflect transcriptional changes. However, we uncover a subset of miRNAs for which abundance is dictated by miRNA gene expression. We confirm that concentration of 5p and 3p miRNA strands depends largely on free energy properties of miRNA duplexes. Unexpectedly, we also find that miRNA strand accumulation can be developmentally regulated. Our data provide a comprehensive map of immunity’s microRNome and reveal the underlying epigenetic and transcriptional forces that shape miRNA homeostasis.