The Caenorhabditis elegans GATA transcription factor
elt-1 has previously been shown to have a central role in the specification of hypodermal (epidermal) cell fates and acts several cell divisions before the birth of hypodermal cells. Here we report that
elt-1 also has essential functions during subsequent development. Reporter gene studies show that
elt-1 expression is maintained in lateral seam cells throughout development and
elt-1 RNA interference experiments support an essential role for
elt-1 in the differentiation of lateral seam cells in the embryo. The maintenance of seam-cell fates in all larval stages including L2d and dauer also requires
elt-1. The
elt-1 RNAi phenotype shows that seam cells are essential for the structural integrity of adult hermaphrodites in the vulval region and for diametric shrinkage during dauer larval formation. By contrast, severe seam-cell loss in the larval stages has little effect on moulting, indicating that the presence of these cells is not essential for this process. The
elt-1 reporter gene is also expressed in neurones of the locomotory circuit. Loss of
elt-1 function during postembryonic development results in a hypermotility phenotype whereas overexpression of
elt-1 leads to a reciprocal phenotype of reduced motility and paralysis. These results suggest that
elt-1 is a key regulator of neuronal function in larvae and adult worms.