title: Sequence analysis of a 212 kb defensin gene cluster on ECA 27q17.
abstract: Defensins are a family of evolutionary ancient antimicrobial peptides consisting of three sub-families: alpha-, beta- and theta-defensins. This investigation was focused on the genomic characterization of equine beta-defensins and the investigation of the potential clustering of beta-defensin genes in the equine genome. Six genomic BAC clones were isolated from the CHORI-241 library and one of these was mapped by FISH to ECA 27q17. This location was confirmed by RH-mapping. The contiguous 212 kb sequence of this clone was determined. Sequence analysis revealed the identification of ten pseudogenes and nine genes, six of which were highly homologous to human beta-defensin DEFB4. Clustering of the beta-defensin genes was confirmed and the order of the genes on the analyzed BAC was related to the corresponding defensin cluster on HSA 8. The knowledge about the sequence and the genomic structure of the equine beta-defensin genes will improve the classification of different paralogous defensin genes and is a prerequisite for subsequent functional studies. Additionally, the first alpha-defensin-like sequence outside the groups of primates, lagomorphs and rodents (glires) was identified.
authors.affiliation: Institute of Animal Breeding and Husbandry, Christian Albrecht University of Kiel, D-24098 Kiel, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Looft
authors.forename: Sven
authors.initials: S
authors.lastname: Paul
authors.forename: Ute
authors.initials: U
authors.lastname: Philipp
authors.forename: Petra
authors.initials: P
authors.lastname: Regenhard
authors.forename: Heidi
authors.initials: H
authors.lastname: Kuiper
authors.forename: Ottmar
authors.initials: O
authors.lastname: Distl
authors.forename: Bhanu P
authors.initials: BP
authors.lastname: Chowdhary
authors.forename: Tosso
authors.initials: T
authors.lastname: Leeb
mesh_terms: D000818:Animals; D001483:Base Sequence; D022202:Chromosomes, Artificial, Bacterial; D033481:Chromosomes, Mammalian; D018388:Codon, Terminator; D019295:Computational Biology; D018076:DNA, Complementary; D030541:Databases, Genetic; D019143:Evolution, Molecular; D005091:Exons; D020440:Gene Duplication; D015723:Gene Library; D023061:Gene Order; D016678:Genome; D006736:Horses / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D011544:Pseudogenes; D021101:Radiation Hybrid Mapping; D017422:Sequence Analysis, DNA; D023084:alpha-Defensins / Q000235:genetics; D023083:beta-Defensins / Q000235:genetics*
chemical_list: D018388:Codon, Terminator; D018076:DNA, Complementary; D023084:alpha-Defensins; D023083:beta-Defensins