Identification of RNAs associated with the epigenetic activator MLL1 in undifferentiated and differentiated CJ7 mouse embryonic stem cells.

The epigenetic activator “Mixed lineage leukemia 1” (Mll1) is paramount for embryonic development and hematopoiesis. We have used RNA-ChIP-on-chip assays to identify long non-coding RNAs, which associate with MLL1 in differentiating CJ7 mouse embryonic stem cells. We identified the long, non-coding RNA (lncRNA) Mistral (Mira), which originates from the spacer DNA region separating Hoxa6 and Hoxa7. Mira supports transcriptional activation of HOXA6 and HOXA7 by recruiting MLL1 to the HOXA6/HOA7 gene cassette. (+RA) CJ7 mESCs [+RA, -LIF, - beta-mercaptoethanol [beta-ME]] chiped with polyclonal antibody to MLL1 vs control A: differentiating (-RA) CJ7 mESCs [-LIF, -beta-ME] chiped with antibody to MLL1; control B: undifferentiated (U) CJ7 cells chiped with antibody to MLL1; C: +RA-Control CJ7 cells [+RA, -LIF, -beta-ME] chiped with mouse antiserum; -RA-Control CJ7 cells chiped with rabbit antiserum; U-Control CJ7 cells chiped with rabbit antiserum. The supplementary bed file contains information showing the association of MLL1 with Mira in differentiating CJ7 mouse embryonic stem cells, and was used as a figure in the manuscript.