Table of Contents



Clustering analysis on the group differentially expressed genes


Goal

To detect common expression patterns in samples and genes on the results of differential expression analysis that we had previously obtained, in the case-control experiment where we used RNA-Seq in mice, and in which we were interested in detecting genes differentially expressed between these 2 groups: wild type (WT) and treated with hormone T3.

Work plan

  1. In this file we have the expression data corresponding to a group of differentially expressed genes: dataset.
  2. In Babelomics, from the Expression / Clustering module, you upload this data and select the clustering by samples. We chose a method of clustering and distance (to begin with, those that are by default). We assign a name to the job and execute it.
  3. We perform the same process but with a clustering by genes.

Questions

  1. Are there groups of individuals with a similar transcriptomic profile? How many groups appear?
  2. Is there any sample that has an anomalous behavior with respect to other subjects?
  3. Are genes with a common expression pattern detected?

More questions

  1. Go to section Expression > Clustering and try several clustering strategies for samples & genes:
    • UPGMA + Euclidean (square)
    • UPGMA + Correlation coeff. (Spearman)
    • Which distance parameter is better for proper clustering?
  2. Repeat the analysis using the same distance parameters and SOTA method.
    • SOTA + Euclidean (square)
    • SOTA + Correlation coeff. (Spearman)
    • Do the results change based on the method or the distance parameter?
  3. Try to cluster your samples with K-means.
    • Set k-value 6 and use Correlation coeff. (Spearman)
    • Repeat the same analysis with k-value 3.
    • Check the results of K-means.
    • Are the results acceptable?
    • Is the dendrogram representing any hierarchy between the samples?
  4. Other strategy with K-means.
    • Set k-value 2 and use Correlation coeff. (Spearman).
    • Can we say that K-means is good to distinguish T3 from WT?