Quantitating transcription factor redundancy: The relative roles of the ELT-2 and ELT-7 GATA factors in the C. elegans endoderm

Two GATA transcription factors, ELT-2 and ELT-7, function in the differentiation of the Caenorhabditis elegans intestine. Though loss of elt-7 causes no discernable phenotype on its own, it significantly enhances intestinal morphology defects in elt-2 loss-of-function mutants. We sought to identify the cohorts of gene targets unique to or shared by ELT-2 and ELT-7 in an effort to determine the logic underlying their differential impact on intestinal development. To quantitate the relative transcriptional influences of ELT-2 and ELT-7, we isolated pure populations of (1) wild-type, (2) elt-2(-), (3) elt-7(-), and (4) elt-7(-); elt-2(-) double mutant L1-stage larvae and compared their transcriptional profiles. Three to four replicates were performed for each condition for a total of 15 samples.