title: Towards the bridging of molecular genetics data across Xenopus species.
abstract: BACKGROUND
  The clawed African frog Xenopus laevis has been one of the main vertebrate models for studies in developmental biology. However, for genetic studies, Xenopus tropicalis has been the experimental model of choice because it shorter life cycle and due to a more tractable genome that does not result from genome duplication as in the case of X. laevis. Today, although still organized in a large number of scaffolds, nearly 85% of X. tropicalis and 89% of X. laevis genomes have been sequenced. There is expectation for a comparative physical map that can be used as a Rosetta Stone between X. laevis genetic studies and X. tropicalis genomic research.
  
  
  RESULTS
  In this work, we have mapped using coarse-grained alignment the 18 chromosomes of X. laevis, release 9.1, on the 10 reference scaffolds representing the haploid genome of X. tropicalis, release 9.0. After validating the mapping with theoretical data, and estimating reference averages of genome sequence identity, 37 to 44% between the two species, we have carried out a synteny analysis for 2,112 orthologous genes. We found that 99.6% of genes are in the same organization.
  
  
  CONCLUSIONS
  Taken together, our results make possible to establish the correspondence between 62 and 65.5% of both genomes, percentage of identity, synteny and automatic annotation of transcripts of both species, providing a new and more comprehensive tool for comparative analysis of these two species, by allowing to bridge molecular genetics data among them.
authors.affiliation: Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile. griadi@utalca.cl.|Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, Talca, Chile. griadi@utalca.cl.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Riadi
authors.affiliation: Fundación Ciencia y Vida, Universidad Andrés Bello, Santiago, Chile. fco.j.ossandon@gmail.com.
authors.forename: Francisco
authors.initials: F
authors.lastname: Ossandón
authors.affiliation: Center for Aging and Regeneration and Millennium Nucleus in Regenerative Biology, Santiago, Chile. jlarrain@bio.puc.cl.
authors.forename: Juan
authors.initials: J
authors.lastname: Larraín
authors.affiliation: Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile. fmelo@bio.puc.cl.
authors.forename: Francisco
authors.initials: F
authors.lastname: Melo
mesh_terms: D000818:Animals; D055028:Comparative Genomic Hybridization; D015321:Gene Rearrangement; D016678:Genome; D020161:Physical Chromosome Mapping; D016415:Sequence Alignment; D026801:Synteny; D014981:Xenopus / Q000145:classification / Q000235:genetics*; D014982:Xenopus laevis / Q000235:genetics*