A polymorphism in the 5'-flanking region of the serotonin transporter (5-HTT) gene affects fear-related behaviors of adult domestic chickens
A polymorphism in the 5'-flanking region of the serotonin transporter (5-HTT) gene affects fear-related behaviors of adult domestic chickens
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DOI：
10.1016/j.bbr.2017.04.051
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发表时间：
2017-07-14
影响因子：
2.7
通讯作者：
Loc Phi van
中科院分区：
文献类型：
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作者：
Krause, E. Tobias;Kjaer, Joergen B.;Loc Phi van
神经5-羟色胺（5-HT）/5-羟色胺转运体（5-HTT）系统参与生理过程和情绪状态的调节。在人类中，5-HTT基因连锁多态性区域中的短（S）等位基因（其降低5-HTT表达）已被证明与行为变化（包括焦虑水平增加）相关。同样在鸟类中，描述了5-HTT基因的多态性，已经发现缺失（D）对生长和运动具有功能性后果。此外，与野生型（W）相比，D-等位基因导致5-HTT表达增加，这是与哺乳动物物种中较低水平的恐惧有关的特征。因此，我们在这里的目的是测试是否在鸡5-HTT基因的多态性也导致各自的恐惧相关行为的变化。本研究采用两种行为模式（旷场、光暗试验）对268只不同基因型（W/W、W/D、D/D）的母鸡进行了恐惧相关行为的测定。两项测试都显示，拥有D等位基因的母鸡比拥有W等位基因的母鸡表现出更低的恐惧水平。鸟类和哺乳动物物种中与恐惧相关的行为中的这些类似结果与5-HIT表达的增加相关。在人类5-HTT基因中，长（L）等位基因与这种增加的表达相关，而在鸡中，它是D等位基因。因此，5-HTT表达增加导致恐惧减少可能是脊椎动物的一般机制。
The neural serotonin (5-HT)/serotonin transporter (5-HTT) system is involved in the regulation of physiological processes and emotional states. In humans, the short (S) allele in the 5-HTT gene-linked polymorphic region, which decreases 5-HTT expression, has been shown to be associated with behavioral changes including an increased level of anxiety. Also in birds a polymorphism in the 5-HTT gene is described, a deletion (D) has been found to have functional consequences on growth and locomotion. Furthermore, the D-allele leads to an increased 5-HTT expression compared to the wild type (W), a feature which is linked to lower levels of fear in mammalian species. Thus, we aimed here to test whether the polymorphism in the chicken 5-HTT gene also leads to respective alternations of fear-related behaviors. We tested 268 hens of three genotypes (W/W, W/D, D/D) in two behavioral paradigms (open field, light dark test) to assess fear-related behavior. Both tests revealed that hens possessing the D-allele showed lower levels of fear than those having the W-allele. These similar outcomes in fear-related behaviors in an avian and a mammalian species are associated with an increased 5-HIT expression. In the human 5-HTT gene, the long (L) allele is linked to such increased expression, whereas in chickens it is the D-allele. Thus, increased 5-HTT expression causing decreased fear may be a general mechanism in vertebrates.