Now that we have the sequence of the human genome, the next step is figuring out what all those genes actually do. Alvis Brazma and his team from the European Molecular Biology Laboratory have taken an important step in doing just that. They have produced a global map of human gene expression.
The data was collected from over 5000 human samples representing a wide assortment of tissue types and diseases. 163 different labs around the world participated in the research.
In order to make sense of all the data, the scientists divided the samples into six major groupings, called ‘continents’. These continents contained cells from the following origins: brain, muscle, blood related (hematopoietic), incompletely differentiated cells, solid tissue cells, and cell lines. You can see the gene expression clusters within each of these groupings in the graph below.
This image shows the 5,372 samples as dots colour-coded for the six major clusters identified by comparing gene expression profiles. The left and right panels of the figure are projections of the same three-dimensional shape viewed from two different perspectives.
(Credit: Brazma / EMBL)