title: Molecular cloning, characterization and tissue distribution of two ostrich β-defensins: AvBD2 and AvBD7.
abstract: Avian β-defensins (AvBDs) are a family of small antimicrobial peptides that play important roles in the innate immunity of birds. Herein, we report on two new ostrich AvBD genes, AvBD2 and AvBD7, which were isolated from the bone marrow of ostriches (Struthio camelus). The coding regions of ostrich AvBD2 and AvBD7 comprised 195 bp and 201bp, which encoded 64 and 66 amino acids, respectively. Homology analysis showed that ostrich AvBD2 had the highest similarity (up to 86%) with the swan goose (Anser cygnoides) AvBD2, while ostrich AvBD7 shared the highest similarity (up to 81%) with chicken AvBD7. Analysis of the codon-usage bias showed that the two ostrich AvBDs had different codon-usage patterns from other AvBDs. The two synthetic AvBD peptides exhibited antibacterial activities against both Gram-positive and Gram-negative bacteria, and these activities decreased significantly in the presence of 100mM NaCl (P<0.01). Real-time reverse transcription-polymerase chain reaction analysis showed that AvBD2 and AvBD7 were widely expressed at different levels in 17 different tissues. This is the first report of the nucleotide sequences of ostrich AvBDs. Further investigations of these two AvBDs may help us to gain new insights into the immune defense system of the ostrich and to make subsequent therapeutic use of ostrich defensins.
authors.affiliation: College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China; Wuhan institute of Animal and Veterinary Science, Wuhan Academy of Agricultural Science, Wuhan, PR China. Electronic address: shun_5560@126.com.
authors.forename: Shun
authors.initials: S
authors.lastname: Lu
authors.affiliation: College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China. Electronic address: kmpeng@mail.hzau.edu.cn.
authors.forename: Kemei
authors.initials: K
authors.lastname: Peng
authors.affiliation: Wuhan institute of Animal and Veterinary Science, Wuhan Academy of Agricultural Science, Wuhan, PR China.
authors.forename: Qishuang
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Wuhan institute of Animal and Veterinary Science, Wuhan Academy of Agricultural Science, Wuhan, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Xiang
authors.affiliation: College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Huazhen
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Song
authors.affiliation: College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Keli
authors.initials: K
authors.lastname: Yang
authors.affiliation: College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Huang
authors.affiliation: College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xiao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D003001:Cloning, Molecular / Q000379:methods; D003062:Codon / Q000235:genetics; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D020310:Struthioniformes / Q000235:genetics* / Q000378:metabolism; D014018:Tissue Distribution / Q000235:genetics*; D023083:beta-Defensins / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D003062:Codon; D023083:beta-Defensins
keywords: Antibacterial activity; Defensin gene; Ostrich; mRNA expression