BACKGROUND To satisfy an increasing demand for dietary protein, the poultry industry has employed genetic selection to increase the growth rate of broilers by over 400% in the past 50 years. Although modern broilers reach a marketable weight of ~ 2 kg in a short span of 35 days, a speed twice as fast as a broiler 50 years ago, the expedited growth has been associated with several negative detrimental consequences. Aside from heart and musculoskeletal problems, which are direct consequences of additional weight, the immune response is also thought to be altered in modern broilers. RESULTS Given that identifying the underlying genetic basis responsible for a less sensitive innate immune response would be economically beneficial for poultry breeding, we decided to compare the genomes of two unselected meat control strains that are representative of broilers from 1957 and 1978, and a current commercial broiler line. Through analysis of genetic variants, we developed a custom prioritization strategy to identify genes and pathways that have accumulated genetic changes and are biologically relevant to immune response and growth performance. Our results highlight two genes, TLR3 and PLIN3, with genetic variants that are predicted to enhance growth performance at the expense of immune function. CONCLUSIONS Placing these new genomes in the context of other chicken lines, reveal genetic changes that have specifically arisen in selective breeding programs that were implemented in the last 50 years.

中文翻译：

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肉鸡选育中与免疫相关的遗传变异的积累。

背景技术为了满足对饮食蛋白质的不断增长的需求，家禽业已经采用遗传选择在过去的50年中使肉鸡的生长速度提高了400％以上。尽管现代肉鸡在短短的35天内就达到了约2公斤的适销体重，速度是50年前肉鸡的两倍，但生长速度加快却带来了若干不利的不利后果。除了心脏和肌肉骨骼问题（这是体重增加的直接后果）之外，现代肉鸡还认为免疫反应也发生了变化。结果鉴于确定导致较低的先天免疫反应的潜在遗传基础对家禽育种在经济上是有利的，我们决定比较两种未选择的肉类控制菌株的基因组，它们分别代表了1957年和1978年的肉鸡以及目前的商业肉鸡品系。通过对遗传变异的分析，我们开发了一种自定义优先级排序策略，以识别积累了遗传变化并在生物学上与免疫反应和生长性能相关的基因和途径。我们的结果突出了两个基因TLR3和PLIN3，它们具有遗传变异，预计会以牺牲免疫功能为代价来增强生长性能。结论将这些新基因组置于其他鸡系的背景下，揭示了过去50年实施的选择性育种计划中特别出现的遗传变化。我们开发了一种自定义优先级排序策略，以识别积累了遗传变化并在生物学上与免疫反应和生长性能相关的基因和途径。我们的结果突出了两个基因TLR3和PLIN3，它们具有遗传变异，预计会以牺牲免疫功能为代价来增强生长性能。结论将这些新基因组置于其他鸡系的背景下，揭示了过去50年实施的选择性育种计划中特别出现的遗传变化。我们开发了一种自定义优先级排序策略，以识别积累了遗传变化并在生物学上与免疫反应和生长性能相关的基因和途径。我们的结果突出了两个基因TLR3和PLIN3，它们具有遗传变异，预计会以牺牲免疫功能为代价来增强生长性能。结论将这些新基因组置于其他鸡系的背景下，揭示了过去50年实施的选择性育种计划中特别出现的遗传变化。预计会以牺牲免疫功能为代价来增强生长性能的遗传变异。结论将这些新基因组置于其他鸡系的背景下，揭示了过去50年实施的选择性育种计划中特别出现的遗传变化。预计会以牺牲免疫功能为代价来增强生长性能的遗传变异。结论将这些新基因组置于其他鸡系的背景下，揭示了过去50年实施的选择性育种计划中特别出现的遗传变化。