The GATA-factor elt-2 is essential for formation of the Caenorhabditis elegans intestine

Abstract

The Caenorhabditis elegans elt-2 gene encodes a single-finger GATA factor, previously cloned by virtue of its binding to a tandem pair of GATA sites that control the gut-specific ges-1 esterase gene. In the present paper, we show that elt-2 expression is completely gut specific, beginning when the embryonic gut has only two cells (one cell cycle prior to ges-1 expression) and continuing in every cell of the gut throughout the life of the worm. When elt-2 is expressed ectopically using a transgenic heat-shock construct, the endogenous ges-1 gene is now expressed in most if not all cells of the embryo; several other gut markers (including a transgenic elt-2-promoter::lacZ reporter construct designed to test for elt-2 autoregulation) are also expressed ectopically in the same experiment. These effects are specific in that two other C. elegans GATA factors (elt-1 and elt-3) do not cause ectopic gut gene expression. An imprecise transposon excision was identified that removes the entire elt-2 coding region. Homozygous elt-2 null mutants die at the L1 larval stage with an apparent malformation or degeneration of gut cells. Although the loss of elt-2 function has major consequences for later gut morphogenesis and function, mutant embryos still express ges-1. We suggest that elt-2 is part of a redundant network of genes that controls embryonic gut development; other factors may be able to compensate for elt-2 loss in the earlier stages of gut development but not in later stages. We discuss whether elements of this regulatory network may be conserved in all metazoa.

Burkholderia pseudomallei suppresses Caenorhabditis elegans immunity by specific degradation of a GATA transcription factor

“…We next determined the effects of infection on ELT-2 protein levels in intact worms using a nuclear ELT-2:: GFP quantitation assay. First, we infected JM90 transgenic worms that express an ELT-2::GFP fusion protein under the control of its native promoter (21). Over the course of infection, we compared the intensity and distribution of ELT-2::GFP fluorescence (Fig.…”

cdk-7 is required for mRNA transcription and cell cycle progression in Caenorhabditis elegans embryos

“…The following alleles and genetic rearrangements were used during the course of this study: axEx1092 (hsp16-1:his-24:GFP) (GFP ϭ green fluorescent protein), wIs28 (end-1:GFP) (26), wIs84 (elt-2:GFP) (27) Mapping and Cloning. ax224 was outcrossed two times and mapped using 3-factor mapping and deficiency complementation.…”

Regulated Disruption of Inositol 1,4,5-Trisphosphate Signaling inCaenorhabditis elegansReveals New Functions in Feeding and Embryogenesis

“…The percentage of embryos corresponding to each of the main phenotypes was quantified from observation of terminal phenotypes. ELT-2 expression was characterized by establishing transgenic animals carrying the relevant IP 3 sponge construct in the strain JM73, which carries an integrated elt-2::gfp fusion (Fukushige et al, 1998). Green fluorescent protein (GFP) was visualized using a Leica SP confocal microscope.…”

“…To further define when in E-cell development the differentiation process goes awry we investigated the fate of the E lineage by using an elt-2::gfp transgene (Fukushige et al, 1999). ELT-2 is a gut cell-specific GATA family transcription factor that is first expressed at the 2E cells stage (Fukushige et al, 1998). Overall, expression of ELT-2::GFP was observed in only 35.1% of embryos in super-sponge worms, compared with 95.9% for the controlsponge ( Figure 5, L-O).…”