The T-box transcription factors TBX-37 and TBX-38 link GLP-1/Notch signaling to mesoderm induction in C. elegans embryos.
The four-cell C. elegans embryo contains two sister cells called ABa and ABp that initially have equivalent abilities to produce ectodermal cell types. Multiple Notch-mediated interactions occur during the early cell divisions that diversify the ABa and ABp descendants. The first interaction determines the pattern of ectodermal cell types produced by ABp. The second interaction induces two ABa granddaughters to become mesodermal precursors. We show that T-box transcription factors called TBX-37 and TBX-38 are essential for mesodermal induction, and that these factors are expressed in ABa, but not ABp, descendants. We provide evidence that the first Notch interaction functions largely, if not entirely, to prevent TBX-37, TBX-38 expression in ABp descendants. Neither the second Notch interaction nor TBX-37, TBX-38 alone are sufficient for mesodermal induction, indicating that both must function together. We conclude that TBX-37, TBX-38 play a key role in distinguishing the outcomes of two sequential Notch-mediated interactions.
Good
Kathryn
K
Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
Ciosk
Rafal
R
Nance
Jeremy
J
Neves
Alexandre
A
Hill
Russell J
RJ
Priess
James R
JR
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage; D004627:Embryonic Induction / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology / Q000502:physiology*; D008969:Molecular Sequence Data; D051880:Receptors, Notch; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism*; D019076:Transgenes
D029742:Caenorhabditis elegans Proteins; C060620:Glp-1 protein, C elegans; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D051880:Receptors, Notch; D020825:T-Box Domain Proteins