title: Recombination of the porcine X chromosome: a high density linkage map.
abstract: BACKGROUND
  Linkage maps are essential tools for the study of several topics in genome biology. High density linkage maps for the porcine autosomes have been constructed exploiting the high density data provided by the PorcineSNP60 BeadChip. However, a high density SSCX linkage map has not been reported up to date. The aim of the current study was to build an accurate linkage map of SSCX to provide precise estimates of recombination rates along this chromosome and creating a new tool for QTL fine mapping.
  
  
  RESULTS
  A female-specific high density linkage map was built for SSCX using Sscrofa10.2 annotation. The total length of this chromosome was 84.61 cM; although the average recombination rate was 0.60 cM/Mb, both cold and hot recombination regions were identified. A Bayesian probabilistic to genetic groups and revealed that the animals used in the current study for linkage map construction were likely to be carriers of X chromosomes of European origin. Finally, the newly generated linkage map was used to fine-map a QTL at 16 cM for intramuscular fat content (IMF) measured on longissimus dorsi. The sulfatase isozyme S gene constitutes a functional and positional candidate gene underlying the QTL effect.
  
  
  CONCLUSIONS
  The current study presents for the first time a high density linkage map for SSCX and supports the presence of cold and hot recombination intervals along this chromosome. The large cold recombination region in the central segment of the chromosome is not likely to be due to structural differences between X chromosomes of European and Asian origin. In addition, the newly generated linkage map has allowed us to fine-map a QTL on SSCX for fat deposition.
authors.affiliation: Departamento de Mejora Genética Animal, INIA, Ctra. De la Coruña km. 7, Madrid, 28040, Spain. avila@inia.es.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Fernández
authors.affiliation: Departamento de Mejora Genética Animal, INIA, Ctra. De la Coruña km. 7, Madrid, 28040, Spain. Maria.Munoz@roslin.ed.ac.uk.|The Roslin Institute and R(D)SVS, University of Edinburgh, Midlothian, EH25 9RG, UK. Maria.Munoz@roslin.ed.ac.uk.
authors.forename: María
authors.initials: M
authors.lastname: Muñoz
authors.affiliation: Departamento de Mejora Genética Animal, INIA, Ctra. De la Coruña km. 7, Madrid, 28040, Spain. esalves@inia.es.
authors.forename: Estefânia
authors.initials: E
authors.lastname: Alves
authors.affiliation: Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, UAB, Bellaterra, 08193, Spain. JosepMaria.Folch@uab.cat.|Present Address: Centre for Research in Agricultural Genomics (CRAG), Consortium CSIC-IRTA-UAB-UB, Edifici CRAG, Campus Universitat Autonoma Barcelona, Bellaterra, 08193, Spain. JosepMaria.Folch@uab.cat.
authors.forename: Josep María
authors.initials: JM
authors.lastname: Folch
authors.affiliation: Genètica i Millora Animal, IRTA, Av. Alcalde Rovira Roure, 191, Lleida, 25198, Spain. JoseLuis.Noguera@irta.cat.
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Noguera
authors.affiliation: Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, UAB, Bellaterra, 08193, Spain. Miguel.Perez@uab.cat.|Present Address: Centre for Research in Agricultural Genomics (CRAG), Consortium CSIC-IRTA-UAB-UB, Edifici CRAG, Campus Universitat Autonoma Barcelona, Bellaterra, 08193, Spain. Miguel.Perez@uab.cat.|Institut Català de Recerca i Estudis Avançats (ICREA), Barcelona, 08010, Spain. Miguel.Perez@uab.cat.
authors.forename: Miguel Pérez
authors.initials: MP
authors.lastname: Enciso
authors.affiliation: Departamento de Mejora Genética Animal, INIA, Ctra. De la Coruña km. 7, Madrid, 28040, Spain. valdo@inia.es.
authors.forename: Maria Del Carmen
authors.initials: Mdel C
authors.lastname: Rodríguez
authors.affiliation: Departamento de Mejora Genética Animal, INIA, Ctra. De la Coruña km. 7, Madrid, 28040, Spain. silio@inia.es.
authors.forename: Luis
authors.initials: L
authors.lastname: Silió
mesh_terms: D050154:Adiposity / Q000235:genetics; D000818:Animals; D001499:Bayes Theorem; D002874:Chromosome Mapping; D005260:Female; D056726:Genetic Association Studies; D008297:Male; D058977:Molecular Sequence Annotation; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D011995:Recombination, Genetic; D034421:Sus scrofa / Q000235:genetics*; D014960:X Chromosome / Q000235:genetics*