COMPARATIVE TRANSCRIPTOMIC AND PROTEOMIC ANALYSIS OF LGR5+ve STEM CELLS AND THEIR DAUGHTERS (AFFYMETRIX ARRAYS)

The identification of Lgr5 as an intestinal stem cell marker has made it possible to isolate and study primary intestinal stem cells. Applying quantitative mass spectrometry as well as transcriptomic analysis, we profiled the protein and gene changes between FACS-sorted Lgr5+ve stem cells and their immediate undifferentiated daughter cells. The overall comparison of mRNA and protein levels revealed a high level of correlation, implying that the initial control of intestinal stem cell biology occurs largely at the mRNA level. Taken together, our study presents a valuable resource for the study of intestinal stem cell biology. We used cell fractions of intestines from Lgr5-EGFP-ires-CreERT2 mice, expressing GFP under the control of the Lgr5 promoter. RNA was isolated from two FACS sorted cell populations, one expressing GFP at high levels (GFPbright) and the other expressing GFP at low levels (GFPdim). The gates set to sort cells for the expression profiling were the same as for the cells used for the mass spectometry analysis. cRNA from GFPbright and GFPdim cells from three different sorts (each combining three to four mice) were hybridized on Affymetrix Mouse HT MG-430 PM plate arrays.