title: Expanding the view on the evolution of the nematode dauer signalling pathways: refinement through gene gain and pathway co-option.
abstract: Signalling pathways underlie development, behaviour and pathology. To understand patterns in the evolution of signalling pathways, we undertook a comprehensive investigation of the pathways that control the switch between growth and developmentally quiescent dauer in 24 species of nematodes spanning the phylum.
  
  
  
  Our analysis of 47 genes across these species indicates that the pathways and their interactions are not conserved throughout the Nematoda. For example, the TGF-β pathway was co-opted into dauer control relatively late in a lineage that led to the model species Caenorhabditis elegans. We show molecular adaptations described in C. elegans that are restricted to its genus or even just to the species. Similarly, our analyses both identify species where particular genes have been lost and situations where apparently incorrect orthologues have been identified.
  
  
  
  Our analysis also highlights the difficulties of working with genome sequences from non-model species as reliance on the published gene models would have significantly restricted our understanding of how signalling pathways evolve. Our approach therefore offers a robust standard operating procedure for genomic comparisons.
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada.|Current address: MIVEGEC (UMR CNRS/IRD/UM 5290), Montpellier, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Gilabert
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada.
authors.forename: David M
authors.initials: DM
authors.lastname: Curran
authors.affiliation: Biomolecular Research Group, School of Human and Life Sciences, Canterbury Christ Church University, Canterbury, UK.
authors.forename: Simon C
authors.initials: SC
authors.lastname: Harvey
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada. jwasmuth@ucalgary.ca.
authors.forename: James D
authors.initials: JD
authors.lastname: Wasmuth
mesh_terms: D000818:Animals; D005075:Biological Evolution; D015415:Biomarkers; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D008024:Ligands; D009348:Nematoda / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D011485:Protein Binding; D015398:Signal Transduction
chemical_list: D015415:Biomarkers; D008024:Ligands