简介：Allergies May Have Been Bequeathed by Neandertals过敏源于尼安德特人？撰文/播音 克里斯托弗·因塔利亚塔（Christopher Intagliata）翻译 Meatle审校 陈娉莹Many non-African humans today have genes—which apparently made it into us via Neandertals—that ramp up resistance to pathogens, but bring on allergies, too. 对于现今居住在非洲以外的人类而言，他们的一些基因显然地是来自尼安德特人。这些基因提升了我们对病原体的抵抗力的同时，也为我们带来了过敏。Homo sapiens may dominate Europe and Asia today. But hundreds of thousands of years ago—long before we got there—the land was ruled by our now-extinct cousins, the Neandertals and Denisovans. "One important thing to realize is that, given that Neandertals and Denisovans had lived in Europe and Asia for such an extended time they were probably quite well adapted to the local conditions." Janet Kelso, a computational biologist at the Max Planck Institute for Evolutionary Anthropology. "So they were well adapted to the pathogens, to the foods that were available, to the climate."今天，智人占领了整个欧亚大陆。但在数十万年前，在人类还没存在之前，统治着这片土地的是人类现已灭绝的近亲，尼安德特人与丹尼索瓦人。“重要的是，尼安德特人与丹尼索瓦人在欧亚的土地上居住了如此长的一段时间，他们应该充分适应了这片土地。”来自马克斯普朗克演化人类学研究所的计算生物学家，珍妮特·凯尔索说，“因此他们适应了这片土地上的病原体，到可获得的食物，到气候。”The invading newcomers probably found themselves less well adapted to the local conditions. So when H. sapiens shacked up with their close evolutionary relatives, it gave them a shot at picking up some advantageous genes. 这片土地的新入侵者可能发现他们并不能很好地适应本地的环境。因此当智人和那些近亲混在一起后，得到了获得优势基因的机会。Kelso and her colleagues hunted modern human genomes for strings of DNA that closely resembled those known to be from Neandertals and Denisovans. And indeed, on human chromosome number four they found a stretch of archaic DNA, 140,000 bases long. 凯尔索和她的同僚在现代人类基因组上寻找与已知的尼安德特人与丹尼索瓦人相似的DNA序列。并且，在人类的4号染色体上，他们找到了长度为140,000个单位的古老DNA序列。The genomes of many non-African humans today have this sequence, which includes a cluster of genes that code for Toll-like receptors, or TLRs—a type of immune protein that sniffs out pathogens. And it turns out that archaic variants of that gene are associated with lower microbial loads in present-day humans—a trait that may have been quite valuable to our ancestors as they settled new lands. The study appears in the American Journal of Human Genetics. [Dannemann et al, Introgression of Neandertal- and Denisovan-like Haplotypes Contributes to Adaptive Variation in Human Toll-like Receptors]现今居住在非洲以外的人类身上的基因组都具有这个相同的序列，包含了编码Toll样受体（Toll-like receptors, TLRs），一种可以识别病原体的蛋白质的一簇基因。。结果发现这组基因序列的古老变异，在现代人类体内，与低微生物容量相关。这个特性对于我们的祖先适应新的聚居地可能有着相当重要的作用。这项研究发表在《美国人类遗传学杂志》上。Problem is, that increased immune vigilance has a side effect: allergies. “Our speculation is that this is some kind of trade-off, right? In the past you needed to resist some kind of pathogen, and the trade-off or sacrifice you have to make for that is some increased responsiveness to nonpathogenic allergens." So next time some of you get the springtime sniffles, blame your distant ancestor—the one with the heavy brow ridge.问题是，免疫系统性能的上升也带来了相应的副作用——过敏反应。“我们推测这是某种取舍。在过去我们需要抵抗一些病原体，作为代价，或者是牺牲，我们需要提升对一些非病原体的反应。”所以下一次当你患上花粉症的时候，怪你那眉骨很高的远亲去吧。原文地址：-may-have-been-bequeathed-by-neandertals/（题图来源：www.allergyandasthmanwf.com）