HUMAN COLON STEM CELL AND CRYPT DYNAMICS

描述(由申请人提供)： 人们对人类隐窝干细胞知之甚少。尽管战略创造了 并跟随可见的墓穴标记对人类来说是不切实际的，这可能是可能的 分析内在地记录着隐秘历史的内源序列。至 在没有实验的情况下更好地区分其他相同的加密 干预后，以表观遗传模式作为细胞命运标志。甲基化 表现出体细胞遗传和随机的位置独立变化 可能在相邻的CpG站点中创建二进制信息字符串或标签 随着时间的推移而变化。代替肉眼检查，甲基化标签内容 对单个隐窝进行采样，并用亚硫酸氢盐测序法进行读取。标签位于 三个可能是中性的基因座在隐窝之间和细胞之间是不同的。 在墓穴里。甲基化随着年龄的增长而增加，但在隐窝之间是镶嵌的， 以及单个隐窝内的等位基因和基因座之间的差异。一些墓穴是 准克隆，因为它们包含的唯一标记比预期的多 单个干细胞。用聚合法分析复杂的表观遗传模式 理论上与多个干细胞存在的隐窝壁龛更一致 通过周期性对称除法进行替换。甲基化标记显示正常 人类的隐窝寿命很长，含有多个干细胞，经历了连续 纯化，并在某些基因座积累随机甲基化错误。建议 研究将进一步验证甲基化标签作为细胞命运标记和更好的 描述正常人结肠中干细胞的动力学。

DESCRIPTION (Provided by Applicant): Little is known about human crypt stem cells. Although strategies which create and follow visible crypt markers are impractical for humans, it may be possible to analyze endogenous sequences which inherently record crypt histories. To better distinguish between otherwise identical crypts without experimental intervention, epigenetic patterns were used as cell fate markers. Methylation exhibits somatic inheritance and random site independent changes which potentially create binary information strings or tags in adjacent CpG sites that drift with time. Instead of visual examinations, methylation tag contents of individual crypts are sampled and read with bisulfite sequencing. Tags at three presumably neutral loci were different between crypts and between cells within crypts. Methylation increased with aging but was mosaic between crypts, and between alleles and loci within single crypts. Some crypts were quasi‑clonal because they contained more unique tags than expected from a single stem cell. The complex epigenetic patterns analyzed with coalescence theory were more consistent with crypt niches in which multiple stem cells are replaced through periodic symmetric divisions. Methylation tags suggest normal human crypts are long lived, contain multiple stem cells, undergo continuous purification, and accumulate random methylation errors at some loci. Proposed studies will further verify methylation tags as cell fate markers and better characterize stem cell dynamics in normal human colon.