Figure 6

miRNAs space in unilineage culture of cord blood HPCs. (A) Self-organizing maps of entire microRNA space for the E, G, MK and Mo differentiation pathways. The miRNAs data sets (N = 627 all miRNAs analysed, N = 195 and N = 92 miRs having in at least a sample signal >1% or >4% respectively of maximum value) and same-sized Random Numbers sets were clustered using the GEDI software into nearly-squared grids composed by miniclusters. On the left, data set analysed for each line is defined, on the top of each column lineage and culture time are indicated, below each grid the Pearson correlation with CD34⁺ (or with first sample for Random Numbers) is reported. In the grids each pixel corresponds to a minicluster that is located at the same position in all the grids of the same line and is composed by a variable small group of miRNAs sharing a similar expression pattern, whose number is indicated by the Gene Density Map. On the right grid size (pixel number) is indicated. Colour of each minicluster indicates the mean of log₂-transformed expression value of corresponding miRNAs or Random Numbers, as indicated on the column bar on the right. (B) Progressive displacement in time measured in terms of Pearson correlation (r) with CD34⁺ profile, as computed across the entire microRNA space (top) and on a random extraction of microRNAs. (C) Multidimensional Scaling plots of the among lineages distances, as computed on the microRNA space at three different steps of differentiation. The average radius increases in time consistently with the progressive differentiation of lineages, while the relative distances between samples do not remain linearly invariant. (D) Distances between lineages determined by computing their miRNA mutual correlations at different time points.