title: Comparative analysis of catfish BAC end sequences with the zebrafish genome.
abstract: BACKGROUND
  Comparative mapping is a powerful tool to transfer genomic information from sequenced genomes to closely related species for which whole genome sequence data are not yet available. However, such an approach is still very limited in catfish, the most important aquaculture species in the United States. This project was initiated to generate additional BAC end sequences and demonstrate their applications in comparative mapping in catfish.
  
  
  RESULTS
  We reported the generation of 43,000 BAC end sequences and their applications for comparative genome analysis in catfish. Using these and the additional 20,000 existing BAC end sequences as a resource along with linkage mapping and existing physical map, conserved syntenic regions were identified between the catfish and zebrafish genomes. A total of 10,943 catfish BAC end sequences (17.3%) had significant BLAST hits to the zebrafish genome (cutoff value <or= e(-5)), of which 3,221 were unique gene hits, providing a platform for comparative mapping based on locations of these genes in catfish and zebrafish. Genetic linkage mapping of microsatellites associated with contigs allowed identification of large conserved genomic segments and construction of super scaffolds.
  
  
  CONCLUSIONS
  BAC end sequences and their associated polymorphic markers are great resources for comparative genome analysis in catfish. Highly conserved chromosomal regions were identified to exist between catfish and zebrafish. However, it appears that the level of conservation at local genomic regions are high while a high level of chromosomal shuffling and rearrangements exist between catfish and zebrafish genomes. Orthologous regions established through comparative analysis should facilitate both structural and functional genome analysis in catfish.
authors.affiliation: The Fish Molecular Genetics and Biotechnology Laboratory, Department of Fisheries and Allied Aquacultures and Program of Cell and Molecular Biosciences, Aquatic Genomics Unit, Auburn University, Auburn, AL 36849, USA. lzh0003@auburn.edu
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Yanliang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Shaolin
authors.initials: S
authors.lastname: Wang
authors.forename: Parichart
authors.initials: P
authors.lastname: Ninwichian
authors.forename: Benjaporn
authors.initials: B
authors.lastname: Somridhivej
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
authors.forename: Jason
authors.initials: J
authors.lastname: Abernathy
authors.forename: Huseyin
authors.initials: H
authors.lastname: Kucuktas
authors.forename: Zhanjiang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D002397:Catfishes / Q000235:genetics*; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics*; D020451:Contig Mapping; D008040:Genetic Linkage; D016678:Genome / Q000235:genetics*; D023281:Genomics; D018895:Microsatellite Repeats / Q000235:genetics; D017422:Sequence Analysis, DNA; D026801:Synteny; D015027:Zebrafish / Q000235:genetics*