The C. elegans glycosyltransferase BUS-8 has two distinct and essential roles in epidermal morphogenesis.
Ventral enclosure in Caenorhabditis elegans involves migration of epidermal cells over a neuroblast substrate and subsequent adhesion at the ventral midline. Organisation of the neuroblast layer by ephrins and their receptors is essential for this migration. We show that bus-8, which encodes a predicted glycosyltransferase, is essential for embryonic enclosure and acts in or with ephrin signalling to mediate neuroblast organisation and to permit epidermal migration. BUS-8 acts non-cell-autonomously in this process, and likely modifies an extracellular regulator of ephrin signalling and cell organisation. Weak and cold-sensitive alleles of bus-8 show that the gene has a separate and distinct post-embryonic role, being essential for epidermal integrity and production of the cuticle surface. This disorganisation of the epidermis and cuticle layers causes increased drug sensitivity, which could aid the growing use of C. elegans in drug screening and chemical genomics. The viable mutants are also resistant to infection by the pathogen Microbacterium nematophilum, due to failure of the bacterium to bind to the host surface. The two separate essential roles of BUS-8 in epidermal morphogenesis add to our growing understanding of the widespread importance of glycobiology in development.
Partridge
Frederick A
FA
Genetics Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
Tearle
Adam W
AW
Gravato-Nobre
Maria J
MJ
Schafer
William R
WR
Hodgkin
Jonathan
J
D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000201:enzymology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D036342:Ephrins / Q000378:metabolism; D004817:Epidermis / Q000196:embryology*; D040461:Gene Components; D016695:Glycosyltransferases / Q000235:genetics / Q000502:physiology*; D049452:Green Fluorescent Proteins; D008854:Microscopy, Electron; D009024:Morphogenesis / Q000235:genetics / Q000502:physiology*; D016296:Mutagenesis; D015398:Signal Transduction / Q000502:physiology*
D029742:Caenorhabditis elegans Proteins; D036342:Ephrins; D049452:Green Fluorescent Proteins; C530195:BUS-8 protein, C elegans; D016695:Glycosyltransferases