Takeuchi Yukari, Hashizume Chie, Chon Esther Myung Ha, Momozawa Yukihide, Masuda Koji, Kikusui Takefumi, Mori Yuji
Laboratory of Veterinary Ethology, The University of Tokyo.
J Vet Med Sci. 2005 Sep;67(9):861-7. doi: 10.1292/jvms.67.861.
Dopamine and noradrenaline are catecholamine neurotransmitters that are produced by biosynthetic enzymes such as tyrosine hydroxylase (TH) and dopamine beta -hydroxylase (DBH). As a first step to elucidate the genetic background of canine behavioral traits, we selected these genes as targets and sequenced these canine genes, and found that both were highly homologous with those of human beings. Then brain cDNAs derived from ten unrelated Beagles were used to search for polymorphisms in these genes. Four single nucleotide polymorphisms (SNPs) (C97T, G168A, G180A and C264T), one of which (C97T) will cause amino acid substitution in the TH gene, and two SNPs (C789A and A1819G), both of which will cause amino acid substitutions in the DBH gene were identified. The allelic frequencies among five dog breeds (47 Golden Retrievers, 41 Labrador Retrievers, 40 Malteses, 26 Miniature Schnauzers, and 39 Shibas) were examined and found to have significant variation between them with regards to all these SNPs, except for C97T in the TH gene and A1819G in the DBH gene. The polymorphisms of C97T and A1819G were found only in the Shiba. The present results suggest that the polymorphisms of the genes encoding catecholamine biosynthetic enzymes may become important markers for examining the genetic background of behavioral characteristics in dogs.
多巴胺和去甲肾上腺素是由酪氨酸羟化酶（TH）和多巴胺β-羟化酶（DBH）等生物合成酶产生的儿茶酚胺神经递质。作为阐明犬类行为特征遗传背景的第一步，我们选择这些基因作为靶点并对犬类基因进行测序，发现它们与人类基因高度同源。然后，我们使用来自十只无关小猎犬的脑cDNA来寻找这些基因中的多态性。我们鉴定出四个单核苷酸多态性（SNP）（C97T、G168A、G180A和C264T），其中一个（C97T）会导致TH基因中的氨基酸替换，以及两个SNP（C789A和A1819G），这两个都会导致DBH基因中的氨基酸替换。我们检测了五个犬种（47只金毛寻回犬、41只拉布拉多寻回犬、40只马尔济斯犬、26只迷你雪纳瑞犬和39只柴犬）之间的等位基因频率，发现除了TH基因中的C97T和DBH基因中的A1819G之外，所有这些SNP在它们之间都有显著差异。C97T和A1819G的多态性仅在柴犬中发现。目前的结果表明，编码儿茶酚胺生物合成酶的基因多态性可能成为研究犬类行为特征遗传背景的重要标记。
