Closing in on a Complete Human Genome
February 23, 2021
(Nature) – With a complex and diverse topography of genes and regulatory sequences, the human genome is often likened to a landscape. But in many places, this terrain is less dramatic vista and more desert highway: vast and repetitive. Consider a chromosome’s centromere, which links its two gene-laden arms. Centromeres comprise thousands of near-identical ?-satellite sequences — 171-base-pair units that need to be correctly organized to ensure chromosomal stability and cell division. Yet two decades after the publication of the draft human genome, these and other challenging DNA features remain as stubborn gaps in our chromosomal atlas. And, until a few years ago, some researchers despaired of ever filling them.