The Caenorhabditis elegans Distal‐less ortholog ceh‐43 is required for development of the anterior hypodermis

Abstract

Homeobox genes of the Distalless (Dll) class are expressed in developing appendages as well as in the central nervous system in invertebrates and vertebrates. Mutant analyses in mice and Drosophila have implicated these genes in outgrowth of structures, cell adhesion, cell migration, and cell fate decisions. We have investigated the expression and function of ceh-43, the Dll ortholog from the nematode Caenorhabditis elegans, by using gfp reporter constructs and double-stranded RNA-mediated interference (RNAi). Our results show that, as in the fly, the C. elegans Dll ortholog seems to play a role in cell adhesion. An antibody against the butterfly Distal-less homeodomain stains the nervous system of C. elegans embryos (Panganiban et al. [1997] Proc Natl Acad Sci USA. 94:5162-5166). GFP expression under the control of the ceh-43 promoter looks similar, although strong expression is primarily confined to the head hypodermis and to neuronal support cells. ceh-43(RNAi) results in 100% lethality at embryonic or early larval stages. At the beginning of morphogenesis, ceh-43(RNAi) embryos start to lose cells through a hole in the head hypodermis. They either rupture anteriorly as elongation proceeds, or they elongate normally to threefold egg length with the pharynx not connected to the mouth. Elongated ceh-43(RNAi) animals die before or soon after hatching with a fluid-filled pseudocoel and large vacuoles. These phenotypes suggest a role for ceh-43 in development of adhesive properties in the head hypodermis that connects the epithelia of the skin and the digestive tract. Furthermore, possible defects in the excretory system may result at least in part from a requirement for ceh-43 in the CAN neurons where ceh-43::gfp is also expressed.

Alternative Polyadenylation Directs Tissue-Specific miRNA Targeting in Caenorhabditis elegans Somatic Tissues

“…In contrast with the hypodermis, the seam cells express a much smaller pool of 105 unique genes (Figure 2B). Two genes in this group— ceh-10 and ceh-43 —are homeobox transcription factors primarily known to be involved in neural fate specification (Altun-Gultekin et al 2001; Aspock and Burglin 2001) and may promote neuroblast formation resulting from seam cell asymmetric divisions in development (Joshi et al 2010). Of the genes uniquely expressed in seam cells, 67 have no function described so far and need to be further investigated.…”

A combinatorial regulatory signature controls terminal differentiation of the dopaminergic nervous system in C. elegans

“…ceh-43 encodes the sole C. elegans ortholog of the fly Distalless and vertebrate Dlx homeobox genes (Aspock and Burglin 2001). In vertebrates, Dlx genes have been implicated in neuronal patterning (Panganiban and Rubenstein 2002), but their roles in terminal neuron differentiation have not previously been described.…”

The Molecular Basis of Organ Formation: Insights From theC. elegansForegut

“…The predicted transcription factors ast-1/ETS TF, die-1/ZnF, unc-39/SixTF, ceh-43/distal-less , and elt-5/GATA are associated with Pun phenotypes, but their targets are unknown (Aspock & Burglin 2001, Heid et al 2001, Koh et al 2002, Schmid et al 2006, Yanowitz et al 2004). Double mutant combinations between lin-35/Rb and the ubiquitin conjugating enzyme ubc-18 (Fay et al 2003), or between pha-1/ DUF1114 and either ubc-18 or ari-1/Ariadne , lead to a Pun phenotype (Fay et al 2004, Qiu & Fay 2006).…”