The evolution of the hypotetraploid Catolobus pendulus genome – the poorly known sister species of Capsella

Frontiers in Plant Science

Plant Science

Hiroshi Kudoh¹  Perla Farhat²  Terezie Mandáková³  Martin A. Lysak⁴  Jan Divíšek⁵  Dmitry A. German⁶ 

[1] Center for Ecological Research, Kyoto University, Otsu, Japan;Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czechia;Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czechia;Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czechia;Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czechia;National Centre for Biomolecular Research (NCBR), Faculty of Science, Masaryk University, Brno, Czechia;Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czechia;South-Siberian Botanical Garden, Altai State University, Barnaul, Russia;

关键词: chromosome painting;    Hyb-Seq;    Arabidopsis-related model systems;    Brassicaceae;    Cruciferae;    polyploidy;    diploidization;    whole-genome duplication (WGD);   

DOI  :  10.3389/fpls.2023.1165140

 received in 2023-02-13, accepted in 2023-04-04,  发布年份 2023

来源: Frontiers

【 摘 要 】

The establishment of Arabidopsis as the most important plant model has also brought other crucifer species into the spotlight of comparative research. While the genus Capsella has become a prominent crucifer model system, its closest relative has been overlooked. The unispecific genus Catolobus is native to temperate Eurasian woodlands, from eastern Europe to the Russian Far East. Here, we analyzed chromosome number, genome structure, intraspecific genetic variation, and habitat suitability of Catolobus pendulus throughout its range. Unexpectedly, all analyzed populations were hypotetraploid (2n = 30, ~330 Mb). Comparative cytogenomic analysis revealed that the Catolobus genome arose by a whole-genome duplication in a diploid genome resembling Ancestral Crucifer Karyotype (ACK, n = 8). In contrast to the much younger Capsella allotetraploid genomes, the presumably autotetraploid Catolobus genome (2n = 32) arose early after the Catolobus/Capsella divergence. Since its origin, the tetraploid Catolobus genome has undergone chromosomal rediploidization, including a reduction in chromosome number from 2n = 32 to 2n = 30. Diploidization occurred through end-to-end chromosome fusion and other chromosomal rearrangements affecting a total of six of 16 ancestral chromosomes. The hypotetraploid Catolobus cytotype expanded toward its present range, accompanied by some longitudinal genetic differentiation. The sister relationship between Catolobus and Capsella allows comparative studies of tetraploid genomes of contrasting ages and different degrees of genome diploidization.

【 授权许可】

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Copyright © 2023 Farhat, Mandáková, Divíšek, Kudoh, German and Lysak