Witas Henryk W, Płoszaj Tomasz, Jędrychowska-Dańska Krystyna, Witas Piotr J, Masłowska Alicja, Jerszyńska Blandyna, Kozłowski Tomasz, Osipowicz Grzegorz
Department of Molecular Biology, Medical University of Łódź, Łódź, Poland.
Institute of Physics, Nicolaus Copernicus University, Toruń, Poland.
PLoS One. 2015 Apr 8;10(4):e0122384. doi: 10.1371/journal.pone.0122384. eCollection 2015.
Populations from two medieval sites in Central Poland, Stary Brześć Kujawski-4 (SBK-4) and Gruczno, represented high level of lactase persistence (LP) as followed by the LCT-13910*T allele's presence (0.86 and 0.82, respectively). It was twice as high as in contemporaneous Cedynia (0.4) and Śródka (0.43), both located outside the region, higher than in modern inhabitants of Poland (0.51) and almost as high as in modern Swedish population (0.9). In an attempt to explain the observed differences its frequency changes in time were followed between the Middle Neolithic and the Late Middle Ages in successive dairying populations on a relatively small area (radius ∼60km) containing the two sites. The introduction of the T allele to Kuyavia 7.4 Ka BP by dairying LBK people is not likely, as suggested by the obtained data. It has not been found in any of Neolithic samples dated between 6.3 and 4.5 Ka BP. The identified frequency profile indicates that both the introduction and the beginning of selection could have taken place approx. 4 millennia after first LBK people arrived in the region, shifting the value of LP frequency from 0 to more than 0.8 during less than 130 generations. We hypothesize that the selection process of the T allele was rather rapid, starting just after its introduction into already milking populations and operated via high rates of fertility and mortality on children after weaning through life-threatening conditions, favoring lactose-tolerant individuals. Facing the lack of the T allele in people living on two great European Neolithization routes, the Danubian and Mediterranean ones, and based on its high frequency in northern Iberia, its presence in Scandinavia and estimated occurrence in Central Poland, we propose an alternative Northern Route of its spreading as very likely. None of the successfully identified nuclear alleles turned out to be deltaF508 CFTR.
来自波兰中部两个中世纪遗址——旧布热希奇库亚夫斯基-4（SBK-4）和格鲁奇诺的人群，乳糖酶持续性（LP）水平较高，LCT-13910*T等位基因的存在率分别为0.86和0.82。这一比例是同期位于该地区以外的塞迪尼亚（0.4）和什罗德卡（0.43）的两倍，高于波兰现代居民（0.51），几乎与现代瑞典人群（0.9）一样高。为了解释观察到的差异，我们追踪了在包含这两个遗址的相对较小区域（半径约60公里）内，从中新石器时代到中世纪晚期，连续的乳制品生产人群中该等位基因频率随时间的变化。正如所获数据表明的那样，由乳制品生产的线性陶器文化（LBK）人群在7400年前将T等位基因引入库亚维亚的可能性不大。在距今6300年至4500年前的任何新石器时代样本中都未发现该等位基因。确定的频率分布表明，该等位基因的引入和选择开始可能都发生在第一批LBK人群抵达该地区约4000年后，在不到130代的时间里，将LP频率值从0提升至超过0.8。我们推测，T等位基因的选择过程相当迅速，在其刚被引入已经从事乳制品生产的人群后就开始了，并通过断奶后因危及生命的状况导致儿童高生育率和高死亡率来起作用，有利于乳糖耐受个体。鉴于在欧洲两条主要的新石器化路线——多瑙河路线和地中海路线上生活的人群中缺乏T等位基因，以及其在伊比利亚半岛北部的高频率、在斯堪的纳维亚半岛的存在情况和在波兰中部的估计出现率，我们极有可能提出其传播的另一条北方路线。所有成功鉴定出的核等位基因都不是ΔF508囊性纤维化跨膜传导调节因子。
