Characterization and expression of non-polymorphic liver expressed antimicrobial peptide 2: LEAP-2 in the Japanese quail, Coturnix japonica.
Liver-expressed antimicrobial peptide 2 (LEAP-2) is a cationic peptide that plays an important role in innate immunity for host defense. The aim of this study was to characterize the LEAP-2 gene in the Japanese quail (Coturnix japonica). Japanese quail LEAP-2 (CjLEAP-2) was identified from the Japanese quail draft genome database by a local BLAST analysis using chicken LEAP-2 (GgLEAP-2). The exon-intron structure of CjLEAP-2, analyzed from three quails, is composed of three exons, as is the chicken LEAP-2 homolog (GgLEAP-2). An analysis of the coding sequence revealed that CjLEAP-2 is 231 bp long, like GgLEAP-2, and 93% identical to GgLEAP-2 at the nucleic acid level. The predicted amino acid sequence of CjLEAP-2 contained the liver-expressed antimicrobial peptide 2-precursor domain and four cysteine residues characteristic of the LEAP-2 protein. The amino acid sequence of the mature peptide of CjLEAP-2 was 100% identical to that of GgLEAP-2. We confirmed that CjLEAP-2 was transcribed in at least seven tissues, including the digestive system. Additionally, the mature peptide region of CjLEAP-2 exhibited no polymorphisms in 99 quails from six strains. Taken together, these findings indicate that CjLEAP-2 is non-polymorphic and therefore, it likely plays an important role in the innate immunity of quail as it does in chicken.
NODAI Genome Research Center, Tokyo University of Agriculture, Tokyo, Japan.
Taichiro
T
Ishige
Department of Animal Science, Tokyo University of Agriculture, Atsugi, Japan.
Hiromi
H
Hara
Department of Animal Science, Tokyo University of Agriculture, Atsugi, Japan.
Takashi
T
Hirano
NODAI Genome Research Center, Tokyo University of Agriculture, Tokyo, Japan.|Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan.
Tomohiro
T
Kono
Department of Animal Science, Tokyo University of Agriculture, Atsugi, Japan.
Kei
K
Hanzawa
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D001798:Blood Proteins; D002645:Chickens; D003370:Coturnix / Q000235:genetics* / Q000276:immunology*; D003545:Cysteine; D030541:Databases, Genetic; D005091:Exons; D015870:Gene Expression; D007113:Immunity, Innate / Q000235:genetics*; D008099:Liver / Q000276:immunology* / Q000378:metabolism; D009696:Nucleic Acids; D011110:Polymorphism, Genetic; D000072417:Protein Domains
D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D009696:Nucleic Acids; C475606:liver-expressed antimicrobial peptide 2, human; D003545:Cysteine
Japanese quail; LEAP-2; antimicrobial peptide; mRNA expression; polymorphism