The NK-2 class homeodomain factor CEH-51 and the T-box factor TBX-35 have overlapping function in C. elegans mesoderm development.
The C. elegans MS blastomere, born at the 7-cell stage of embryogenesis, generates primarily mesodermal cell types, including pharynx cells, body muscles and coelomocytes. A presumptive null mutation in the T-box factor gene tbx-35, a target of the MED-1 and MED-2 divergent GATA factors, was previously found to result in a profound decrease in the production of MS-derived tissues, although the tbx-35(-) embryonic arrest phenotype was variable. We report here that the NK-2 class homeobox gene ceh-51 is a direct target of TBX-35 and at least one other factor, and that CEH-51 and TBX-35 share functions. Embryos homozygous for a ceh-51 null mutation arrest as larvae with pharynx and muscle defects, although these tissues appear to be specified correctly. Loss of tbx-35 and ceh-51 together results in a synergistic phenotype resembling loss of med-1 and med-2. Overexpression of ceh-51 causes embryonic arrest and generation of ectopic body muscle and coelomocytes. Our data show that TBX-35 and CEH-51 have overlapping function in MS lineage development. As T-box regulators and NK-2 homeodomain factors are both important for heart development in Drosophila and vertebrates, our results suggest that these regulators function in a similar manner in C. elegans to specify a major precursor of mesoderm.
Broitman-Maduro
Gina
G
Department of Biology, University of California, Riverside, CA 92521, USA. mmaduro@ucr.edu
Owraghi
Melissa
M
Hung
Wendy W K
WW
Kuntz
Steven
S
Sternberg
Paul W
PW
Maduro
Morris F
MF
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001757:Blastomeres / Q000502:physiology; D017173:Caenorhabditis elegans / Q000033:anatomy & histology* / Q000196:embryology* / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D019070:Cell Lineage; D018507:Gene Expression Regulation, Developmental; D055786:Gene Knockout Techniques; D053263:Gene Regulatory Networks / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D008648:Mesoderm / Q000502:physiology*; D008969:Molecular Sequence Data; D010641:Phenotype; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
C544540:CEH-51 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D018398:Homeodomain Proteins; D011993:Recombinant Fusion Proteins; D020825:T-Box Domain Proteins; C514535:TBX-35 protein, C elegans; D014157:Transcription Factors