如果你想知道新养的毛茸茸的小狗是一个逗人喜爱的朋友，还是对路过的人都会咆哮几声，咬上一口，你可能应该检查一下它的基因长度。
日本东京大学的Akitsugu Konno和同事请100位秋田犬的主人填写了他们的杂种狗是不听话还是讨人喜欢的调查问卷。
当研究人员对小狗的脱氧核糖核酸（DNA）展开研究时，他们发现最让人讨厌的公狗往往携带了一个变短的基因，它作为受体对不同的雄性激素作出响应。
这种基因变异产生了一种蛋白质形式，后者之前曾被发现能够对睾丸素作出更加强烈的响应。
这是第一次将犬科动物的进攻性与雄性激素受体中的遗传差异联系起来。
研究人员在本周的《生物学快报》上报告了这一研究成果。
在研究人员调查的秋田犬中超过半数携带了这种变异。而与温和的狗相比，令人讨厌的母狗携带这种短变异的几率并没有增加，这意味着雌性对于这些激素有着不同的响应。（生物谷Bioon.com）
生物谷推荐原文出处：
Biol. Lett. doi: 10.1098/rsbl.2011.0087
Androgen receptor gene polymorphisms are associated with aggression in Japanese Akita Inu
Akitsugu Konno1,2,*, Miho Inoue-Murayama3 and Toshikazu Hasegawa1
We tested for an association between variable number of tandem repeats in the canine androgen receptor (AR) gene and personality differences in Japanese Akita Inu dogs. The polymorphic trinucleotide (CAG) repeat region coding for glutamine in exon 1 of the AR gene was genotyped using genomic DNA obtained from 171 dogs. Three alleles (23, 24 and 26 repeats) were detected, and the allele frequency differed with the coat colour. We assessed the personality profiles of 100 fawn-coloured dogs (54 males and 46 females) based on a questionnaire answered by each dog's owner. The questionnaire consisted of five sub-scales (sociability, playfulness, neuroticism, aggressiveness, distractibility), and the psychometric properties were acceptable based upon internal consistency of the subscales. We found that male dogs with a short allele conferring increased AR function had higher aggressiveness scores than male dogs with longer alleles. By contrast, no evidence was found for a relationship between AR gene variants and personality in females. To our knowledge, our findings provide the first evidence of polymorphism in the AR gene being associated with canine aggression.
