The Caenorhabditis elegans GATA factor elt-1 is essential for differentiation and maintenance of hypodermal seam cells and for normal locomotion.

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.