DNA methylation beta values at 37,488 CpG sites for beluga whales collected in Cook Inlet, Alaska, between 1992 and 2018

A custom DNA methylation array was used to measure methylation levels at 37,488 cytosine-guanine sites (CpGs) in the beluga genome using a calibration dataset of deceased beluga whales with estimated chronological ages (n=69) using tooth growth layers. Data were generated on a bead array using Illumina Infinium technology. IDAT files (with measures of fluorescence from the iScan machine) were produced and normalized data were uploaded here. Data were normalized using the SeSAMe pipeline (Zhou et al., 2018). Date files are uploaded for (1) the epigenetic clock calibration dataset and (2) a dataset of whales of unkown age, or the "biopsy dataset." The calibration dataset is for whales that have chronological ages derived from tooth growth layer group counts. The biopsy dataset consists of whales of unknown age that are living in Cook Inlet and were sampled by biopsy dart in 2016-2018. All samples were of skin tissue. Data here includes (1) beta values for each sample for each probe on the array and (2) detection p-values describing the confidence in those beta values.本研究采用定制DNA甲基化芯片（custom DNA methylation array），基于通过牙齿生长层估算实足年龄的69头死亡白鲸构建的校准数据集，对白鲸基因组中37488个胞嘧啶-鸟嘌呤位点（CpGs）的甲基化水平进行检测。实验依托Illumina Infinium技术的微珠阵列芯片完成数据生成，生成了包含iScan扫描仪荧光检测数据的IDAT文件，并将标准化后的数据上传至此。数据采用SeSAMe分析流程（Zhou等，2018）进行标准化处理。本次上传的数据包含两类：(1) 表观遗传时钟校准数据集；(2) 年龄未知的白鲸数据集，即“活检数据集”。校准数据集对应的样本，其实际年龄通过牙齿生长层组计数得到。活检数据集包含2016-2018年通过活检镖采集样本、栖息于库克湾（Cook Inlet）的年龄未知白鲸。所有样本均取自皮肤组织。本数据集包含两类核心数据：(1) 芯片上每个探针对应各样本的β甲基化值；(2) 用于表征该β值检测置信度的检测p值。