古石器时代的基因重复引发了人类化酶的适应性进化,在农业上占据了位置
bioRxiv : the preprint server for biology
|December 11, 2023
概括
人类氨基酶 (AMY1) 基因拷贝数变异早于农业,在80万年前就发生了重复. 这种遗传特征影响了人类进化过程中适应富含粉的饮食.
科学领域:
- 人类进化遗传学人类进化遗传学
- 营养基因组学 营养基因组学
- 分子人类学分子人类学.
背景情况:
- 粉消化对人类营养至关重要,由由粉酶基因编码的粉酶酶促进.
- 以前的研究将唾液氨酶 (AMY1) 基因拷贝数与农业饮食联系起来,但缺乏核酸水平分辨率以获得进化见解.
- 粉酶位点的复杂结构和拷贝数变异 (CNV) 具有挑战性的进化分析.
研究的目的:
- 在当今和古代人类的核酸分辨率上解决酶位点.
- 研究AMY1基因复制和CNV的进化史和机制.
- 了解AMY1 CNV在人类适应中的作用,特别是在饮食和农业方面.
主要方法:
- 在98名当代人类中,核酸位的核酸水平测序.
- 对AMY1基因拷贝的遗传学重建和哈普洛型分析.
- 考古人类基因组和古代人类基因组 (300-45,000年前) 的分析.
- 研究驱动AMY1 CNV的重组机制.
主要成果:
- 确定了30种不同的AMY1单元型,其编码序列在负选择下演变.
- 全球普遍存在的三副 AMY1 哈普洛类型,起源于现代人类从非洲迁移之前.
- 在古老的原始人中发现了更多的AMY1基因拷贝的证据表明,复制发生在80万年前.
- 在农业出现之前,AMY1 CNV已经存在了很长一段时间,这有助于农业传播的副本数量的适应性增加.
- 非基同源重组驱动了基酶位点的快速并列重复扩张.
结论:
- 氨基酶位点表现出复制和CNV的古老起源,早于农业的出现.
- 在整个进化过程中,AMY1 CNV在人类适应富含粉的饮食方面发挥了重要作用.
- 了解氨基酶位点的基因组结构和进化动态,可以了解人类的营养适应.
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