The genetic architecture of innate fear behavior in chickens is poorly understood. Here, we performed quantitative trait loci (QTL) analysis of innate responses to tonic immobility (TI) and open field (OF) fears in 242 newly hatched chicks of an F₂ population between the native Japanese Nagoya breed and the White Leghorn breed using 881 single nucleotide polymorphism markers obtained by restriction site-associated DNA sequencing. At genome-wide 5% significance levels, four QTL for TI traits were revealed on chromosomes 1–3 and 24. Two of these loci had sex-specific effects on the traits. For OF traits, three QTL were revealed on chromosomes 2, 4 and 7. The TI and OF QTL identified showed no overlaps in genomic regions and different modes of inheritance. The three TI QTL and one OF QTL exerted antagonistic effects on the traits. The results demonstrated that context-dependent QTL underlie the variations in innate TI and OF behaviors.

对鸡先天恐惧行为的遗传结构知之甚少。在这里，我们对 242 只新孵化的 F ₂雏鸡对强直不动 (TI) 和旷场 (OF) 恐惧的先天反应进行了数量性状位点 (QTL) 分析。使用通过限制性位点相关 DNA 测序获得的 881 个单核苷酸多态性标记，在日本本土名古屋品种和白来航品种之间的种群中进行了分析。在全基因组 5% 的显着性水平上，在 1-3 和 24 号染色体上揭示了 TI 性状的四个 QTL。其中两个基因座对这些性状具有性别特异性影响。对于OF性状，在2号、4号和7号染色体上发现了三个QTL。鉴定的TI和OF QTL在基因组区域和不同的遗传模式上没有重叠。3个TI QTL和1个OF QTL对性状产生拮抗作用。结果表明，上下文相关的 QTL 是先天 TI 和 OF 行为变化的基础。