Fig. 1.

A time-series profiling approach to characterize Ras^V12 embryonic cell lines by identifying synexpression groups. Seven independent primary cultures were established from Act5C > UAS-Ras^V12, UAS-GFP embryos, in which ubiquitously expressed Gal4 drives the expression of both Ras^V12 and GFP. High-resolution time-series profiling using RNA-Seq and Affymetrix arrays were generated by sampling five cultures at different passages during cell line derivation over a period of 6 mo. Differential expression of up-regulated genes at late, compared with early, time points, was performed to identify genes associated with the establishment of the final stage of the cultures. Prioritizing these genes, we generated a network of genes with highly correlated temporal expression profiles in the time-series datasets, leading to the identification of synexpression groups.