title: Conservation of long-range synteny and microsynteny between the genomes of two distantly related nematodes.
abstract: BACKGROUND
  Comparisons between the genomes of the closely related nematodes Caenorhabditis elegans and Caenorhabditis briggsae reveal high rates of rearrangement, with a bias towards within-chromosome events. To assess whether this pattern is true of nematodes in general, we have used genome sequence to compare two nematode species that last shared a common ancestor approximately 300 million years ago: the model C. elegans and the filarial parasite Brugia malayi.
  
  
  RESULTS
  An 83 kb region flanking the gene for Bm-mif-1 (macrophage migration inhibitory factor, a B. malayi homolog of a human cytokine) was sequenced. When compared to the complete genome of C. elegans, evidence for conservation of long-range synteny and microsynteny was found. Potential C. elegans orthologs for II of the 12 protein-coding genes predicted in the B. malayi sequence were identified. Ten of these orthologs were located on chromosome I, with eight clustered in a 2.3 Mb region. While several, relatively local, intrachromosomal rearrangements have occurred, the order, composition, and configuration of two gene clusters, each containing three genes, was conserved. Comparison of B. malayi BAC-end genome survey sequence to C. elegans also revealed a bias towards intrachromosome rearrangements.
  
  
  CONCLUSIONS
  We suggest that intrachromosomal rearrangement is a major force driving chromosomal organization in nematodes, but is constrained by the interdigitation of functional elements of neighboring genes.
authors.affiliation: Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, UK.
authors.forename: D B
authors.initials: DB
authors.lastname: Guiliano
authors.forename: N
authors.initials: N
authors.lastname: Hall
authors.forename: S J M
authors.initials: SJ
authors.lastname: Jones
authors.forename: L N
authors.initials: LN
authors.lastname: Clark
authors.forename: C H
authors.initials: CH
authors.lastname: Corton
authors.forename: B G
authors.initials: BG
authors.lastname: Barrell
authors.forename: M L
authors.initials: ML
authors.lastname: Blaxter
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D017178:Brugia malayi / Q000235:genetics; D017173:Caenorhabditis elegans / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D002874:Chromosome Mapping; D017124:Conserved Sequence / Q000235:genetics*; D017238:Genes, Helminth / Q000235:genetics; D016678:Genome; D015801:Helminth Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009348:Nematoda / Q000235:genetics*; D016415:Sequence Alignment; D026801:Synteny / Q000235:genetics*
chemical_list: D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins