FILLING THE GAPS

人类全基因组完整测序100%完成。科学杂志连发6篇文章报告该成就。这是人类生命的“登月计划”。30.5亿对碱基。距离人类数字化又前进了一步。科学的尽头是什么？

Afully sequenced human genome was triumphantly announced more than 20 years ago. However, owing to technological limitations, some ge-nomic regions remained unresolved. Here, Science presents research by the Telomere-to-Telomere (T2T) Consortium, reporting on the endeavor to complete a comprehensive human reference genome. Generated primarily by long-read sequencing of a hydatidiform mole, a doubly haploid growth, this eff ort adds ~200 megabases of genetic information—a full chromo-some’s worth—to the human genome. Through the resolution of previously unsequenceable and unalignable regions, mostly composed of highly repetitive sequences, this reference genome allows for a detailed characterization of the centromeric satellite repeats, trans-posable elements, and segmental duplications. Mapping of genomic sequences, including those from previously published studies, resolves aspects of human ge-netic diversity, including evolutionary comparisons with our primate relatives. Fur-thermore, it allows for identifi cation of how changes in methylation density diff er within and among centromeres and how epigenetics can aff ect the transcription of repeat sequences.These investigations have only begun to tease apart how the T2T reference ge-nome infl uences the detection of biomedically relevant variants and the evolution of genomic regions that determine human traits. Although much remains to be discov-ered, the T2T reference genome provides another celebratory benchmark to observe as we continue to delve into the genetics that underlie our complete selves.