ヘテロログなヒトアクロセントリック染色体間の再結合

Andrea Guarracino^1,2, Silvia Buonaiuto³, Leonardo Gomes de Lima⁴

¹Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, USA.

Nature

|May 10, 2023

まとめ

人間のアクロセントリック染色体には,非同型配列間の再結合を示す擬似同型領域 (PHR) がある. これらの領域は,長期にわたる細胞遺伝的仮説を裏付け,繰り返されるロバートソンの転位を説明する.

科学分野:

ゲノミクス
人間の遺伝子
分子生物学

背景:

人間のアクロセントリック染色体 (SAAC) の短腕は,リボソームDNAとセグメンタル複製を含むホモロジーを示しています.
以前のゲノムアセンブリでは,同性パターンが祖先から生じたのか,それとも再結合によって維持されたのかについて,限られた洞察力しか与えられなかった.

研究の目的:

SAAC のホモロジーの性質と染色体の再編成におけるその役割を調査する.
同性でないアクロセントリック染色体配列の間に再結合が発生するかどうかを判断する.

主な方法:

ヒューマン・パンゲノム・レファレンス・コンソーシアム (HPRC) のデータセットを全体的に比較した.
セントロメアを横断するアクロセントリックコンティグからバリエーショングラフを構成した.
偽同質領域 (PHR) での結合不均衡の崩壊を分析した.

主要な成果:

アクロセントリック染色体内のPHRが特定され,非同位配列間の再結合が示唆されています.
T2T-CHM13アセンブリにおける異質なアクロセントリック染色体間のほぼ同一のコンティグが観察された.
PHRの結合不均衡の急速な衰退が発見され,染色体15を除いて,より高い再結合率を示しています.

結論:

PHRは,繰り返し発生するロバートソンの転位に関する配列および集団ベースの証拠を提供します.
PHRの配置は,逆転重複内のクロスオーバーをサポートし,トランスロケーションブレイクポイントを説明します.
発見は,細胞遺伝学的研究から開発されたロバートソン型転位に基づく仮説を裏付けている.

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