Rescue of Caenorhabditis elegans pharyngeal development by a vertebrate heart specification gene.
Development of pharyngeal muscle in nematodes and cardiac muscle in vertebrates and insects involves the related homeobox genes ceh-22, nkx2.5, and tinman, respectively. To determine whether the nematode and vertebrate genes perform similar functions, we examined activity of the zebrafish nkx2.5 gene in transgenic Caenorhabditis elegans. Here, we report that ectopic expression of nkx2.5 in C. elegans body wall muscle can directly activate expression of both the endogenous myo-2 gene, a ceh-22 target normally expressed only in pharyngeal muscle, and a synthetic reporter construct controlled by a multimerized CEH-22 binding site. nkx2.5 also efficiently rescues a ceh-22 mutant when expressed in pharyngeal muscle. Together, these results indicate that nkx2.5 and ceh-22 provide a single conserved molecular function. Further, they suggest that an evolutionarily conserved mechanism underlies heart development in vertebrates and insects and pharyngeal development in nematodes.
Haun
C
C
Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
Alexander
J
J
Stainier
D Y
DY
Okkema
P G
PG
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D005816:Genetic Complementation Test; D006321:Heart / Q000196:embryology*; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D010614:Pharynx / Q000196:embryology; D014157:Transcription Factors / Q000502:physiology*; D029867:Xenopus Proteins
C109217:CEH-22 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C095552:NKX2-5 protein, human; D014157:Transcription Factors; D029867:Xenopus Proteins