The novel polymorphism of the beta 3-adrenergic receptor gene and its distribution in domestic pigs and wild boars in Asia
The beta 3-adrenergic receptor (ADRB3) is a G protein-coupled receptor that is involved in regulating energy homeostasis. We have studied DNA sequences of porcine ADRB3 to find candidate genetic polymorphisms for economically important growth and performance traits in pigs. Five novel haplotypes derived from the three In/dels and 44 SNPs were identified among domestic pigs and wild boars. Three of them encode non-synonymous amino acid sequences by five missense polymorphisms and a frameshift by a thymine insertion. The amino acid polymorphic sites were distributed as follows: one substitution was in extracellular loop 1, three substitutions were in intracellular loop3 and one substitution and the deletion of two amino acids were at the carboxyl-terminal. There was no polymorphism in the transmembrane domains. In addition, we surveyed the allelic frequency of the thymine insertion that cause frameshift in South-east Asian local pigs, including some commercial breeds and wild boars. This thymine insertion was distributed widely in the domestic pigs and wild boars. The frequencies of this allele were relatively low in Western improved breeds, while they were very common in Asian breeds and wild boars in Asia. This result indicates that this insertion originally occurred in ancient Asian wild boars and then circulated among Asian domestic pigs. This allele also spread over Western breeds, probably through the introgression of Asian pigs into European stocks during the 18th and 19th centuries.
Document Type: Research Article
Affiliations: 1: School of Veterinary Medicine, Azabu University, Sagamihara, 2: Faculty of Agriculture, Kobe University, Nada, Kobe, 3: Faculty of Agriculture, Kagoshima University, Kagoshima, 4: The Cattle Museum, Oshu, 5: Faculty of Agriculture and Veterinary Sciences, Hanoi Agricultural University, Hanoi, Vietnam; 6: Faculty of Animal Science and Veterinary Medicine, Loyal University of Agriculture, Cambodia; 7: Ministry of Agriculture and Forestry, Lao People's Democratic Republic; and 8: Graduate School of Biosphere Science, Hiroshima University, Higashihiroshima, 9: Ministry of Livestock and Fisheries, Union of Myanmar 10: Graduate School of Bioagricultual Sciences, Nagoya University, Nagoya, Japan;
Publication date: June 1, 2007