C. elegans slit acts in midline, dorsal-ventral, and anterior-posterior guidance via the SAX-3/Robo receptor.
Robo receptors interact with ligands of the Slit family. The nematode C. elegans has one Robo receptor (SAX-3) and one Slit protein (SLT-1), which direct ventral axon guidance and guidance at the midline. In larvae, slt-1 expression in dorsal muscles repels axons to promote ventral guidance. SLT-1 acts through the SAX-3 receptor, in parallel with the ventral attractant UNC-6 (Netrin). Removing both UNC-6 and SLT-1 eliminates all ventral guidance information for some axons, revealing an underlying longitudinal guidance pathway. In the embryo, slt-1 is expressed at high levels in anterior epidermis. Embryonic expression of SLT-1 provides anterior-posterior guidance information to migrating CAN neurons. Surprisingly, slt-1 mutants do not exhibit the nerve ring and epithelial defects of sax-3 mutants, suggesting that SAX-3 has both Slit-dependent and Slit-independent functions in development.
Hao
J C
JC
Howard Hughes Medical Institute, Department of Anatomy, The University of California, San Francisco, CA 94143, USA.
Yu
T W
TW
Fujisawa
K
K
Culotti
J G
JG
Gengyo-Ando
K
K
Mitani
S
S
Moulder
G
G
Barstead
R
R
Tessier-Lavigne
M
M
Bargmann
C I
CI
D000818:Animals; D001369:Axons / Q000502:physiology*; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins; D002465:Cell Movement; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D009132:Muscles / Q000294:innervation / Q000502:physiology; D016296:Mutagenesis / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000075385:Netrins; D009474:Neurons / Q000502:physiology / Q000648:ultrastructure; D017434:Protein Structure, Tertiary; D011971:Receptors, Immunologic / Q000235:genetics* / Q000378:metabolism*; D000097905:Roundabout Proteins
D029742:Caenorhabditis elegans Proteins; D049452:Green Fluorescent Proteins; D015801:Helminth Proteins; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; D000075385:Netrins; D011971:Receptors, Immunologic; D000097905:Roundabout Proteins; C078146:UNC-6 protein, C elegans; C492285:slt-1 protein, C elegans