School of Plant Sciences and Food Security, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel.
CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
Genome Biol Evol. 2021 Feb 3;13(2). doi: 10.1093/gbe/evaa220.
Chromosome numbers have been widely used to describe the most fundamental genomic attribute of an organism or a lineage. Although providing strong phylogenetic signal, chromosome numbers vary remarkably among eukaryotes at all levels of taxonomic resolution. Changes in chromosome numbers regularly serve as indication of major genomic events, most notably polyploidy and dysploidy. Here, we review recent advancements in our ability to make inferences regarding historical events that led to alterations in the number of chromosomes of a lineage. We first describe the mechanistic processes underlying changes in chromosome numbers, focusing on structural chromosomal rearrangements. Then, we focus on experimental procedures, encompassing comparative cytogenomics and genomics approaches, and on computational methodologies that are based on explicit models of chromosome-number evolution. Together, these tools offer valuable predictions regarding historical events that have changed chromosome numbers and genome structures, as well as their phylogenetic and temporal placements.
染色体数目被广泛用于描述生物或谱系最基本的基因组属性。尽管提供了强烈的系统发育信号，但在所有分类分辨率水平上，真核生物的染色体数目变化显著。染色体数目的变化通常作为主要基因组事件的指标，最显著的是多倍体和非整倍体。在这里，我们回顾了我们在推断导致谱系染色体数目变化的历史事件方面的最新进展。我们首先描述了导致染色体数目变化的机制过程，重点是结构染色体重排。然后，我们专注于实验程序，包括比较细胞遗传学和基因组学方法，以及基于染色体数演化显式模型的计算方法。这些工具共同提供了有关改变染色体数目和基因组结构的历史事件的有价值的预测，以及它们的系统发育和时间位置。
