科學家完成人類X染色體的完整組裝
作者:
小柯機器人發布時間:2020/7/16 17:42:09
美國國立衛生研究院Adam M. Phillippy等研究人員合作完成了人類X染色體的完整組裝。2020年7月14日,《自然》雜誌在線發表了這項成果。
研究人員報導了超越人類參考基因組(GRCh38)連續性的從頭人類基因組裝配,以及人類染色體的第一個無間隙、端粒到端粒裝配。通過對完整的葡萄胎CHM13基因組進行高覆蓋、超長讀取的納米孔測序,並結合用於質量改進和驗證的補充技術,研究人員實現這一難點。通過集中於人類X染色體3,研究人員重建了約3.1兆鹼基的著絲粒衛星DNA陣列,並消除了當前參考基因組中的全部29個剩餘缺口,包括來自人類假常染色體區域和癌症-睪丸兩性基因家族(CT-X和GAGE)。這些新的序列將被整合到未來的人類參考基因組版本中。
此外,完整的X染色體與超長納米孔數據相結合,使得研究人員可以首次繪製複雜串聯重複序列和衛星陣列的甲基化模式。這些結果表明,整個人類基因組的完成已經觸手可及,這些數據將促進人類染色體的完整繪製。
據了解,經過二十多年的改進,當前的人類參考基因組(GRCh38)是有史以來最準確、最完整的脊椎動物基因組。然而,沒有一條染色體首尾相接,並且數百個未解決的缺口仍然存在。
附:英文原文
Title: Telomere-to-telomere assembly of a complete human X chromosome
Author: Karen H. Miga, Sergey Koren, Arang Rhie, Mitchell R. Vollger, Ariel Gershman, Andrey Bzikadze, Shelise Brooks, Edmund Howe, David Porubsky, Glennis A. Logsdon, Valerie A. Schneider, Tamara Potapova, Jonathan Wood, William Chow, Joel Armstrong, Jeanne Fredrickson, Evgenia Pak, Kristof Tigyi, Milinn Kremitzki, Christopher Markovic, Valerie Maduro, Amalia Dutra, Gerard G. Bouffard, Alexander M. Chang, Nancy F. Hansen, Amy B. Wilfert, Franoise Thibaud-Nissen, Anthony D. Schmitt, Jon-Matthew Belton, Siddarth Selvaraj, Megan Y. Dennis, Daniela C. Soto, Ruta Sahasrabudhe, Gulhan Kaya, Josh Quick, Nicholas J. Loman, Nadine Holmes, Matthew Loose, Urvashi Surti, Rosa ana Risques, Tina A. Graves Lindsay, Robert Fulton, Ira Hall, Benedict Paten, Kerstin Howe, Winston Timp, Alice Young, James C. Mullikin, Pavel A. Pevzner, Jennifer L. Gerton, Beth A. Sullivan, Evan E. Eichler, Adam M. Phillippy
Issue&Volume: 2020-07-14
Abstract: After two decades of improvements, the current human reference genome (GRCh38) is the most accurate and complete vertebrate genome ever produced. However, no one chromosome has been finished end to end, and hundreds of unresolved gaps persist1,2. Here we present a de novo human genome assembly that surpasses the continuity of GRCh382, along with the first gapless, telomere-to-telomere assembly of a human chromosome. This was enabled by high-coverage, ultra-long-read nanopore sequencing of the complete hydatidiform mole CHM13 genome, combined with complementary technologies for quality improvement and validation. Focusing our efforts on the human X chromosome3, we reconstructed the ~3.1 megabase centromeric satellite DNA array and closed all 29 remaining gaps in the current reference, including new sequence from the human pseudoautosomal regions and cancer-testis ampliconic gene families (CT-X and GAGE). These novel sequences will be integrated into future human reference genome releases. Additionally, a complete chromosome X, combined with the ultra-long nanopore data, allowed us to map methylation patterns across complex tandem repeats and satellite arrays for the first time. Our results demonstrate that finishing the entire human genome is now within reach and the data presented here will enable ongoing efforts to complete the remaining human chromosomes.
DOI: 10.1038/s41586-020-2547-7
Source: https://www.nature.com/articles/s41586-020-2547-7