An updated explanation of ancestral karyotype changes and reconstruction of evolutionary trajectories to form Camelina sativa chromosomes

BMC Genomics

Jiaqing Yuan¹  Chao Liu²  Ke Gong²  Weijie Wang²  Pengchuan Sun²  Fanbo Meng²  Zhikang Zhang²  Xiyin Wang³ 

[1] College of Pharmacy, Chengdu University of Traditional Chinese Medicine, 610075, Chengdu, China;School of Life Sciences, North China University of Science and Technology, 063210, Tangshan, Hebei, China;School of Life Sciences, North China University of Science and Technology, 063210, Tangshan, Hebei, China;Institute for Genomics and Bio-Big-Data, Chengdu University of Traditional Chinese Medicine, 610075, Chengdu, China;

关键词: Brassicaceae;    C. sativa;    Chromosome;    Karyotype;    Polyploid;   

DOI  :  10.1186/s12864-020-07081-0

来源: Springer

【 摘 要 】

BackgroundBelonging to lineage I of Brassicaceae, Camelina sativa is formed by two hybridizations of three species (three sub-genomes). The three sub-genomes were diverged from a common ancestor, likely derived from lineage I (Ancestral Crucifer karyotype, ACK). The karyotype evolutionary trajectories of the C. sativa chromosomes are currently unknown. Here, we managed to adopt a telomere-centric theory proposed previously to explain the karyotype evolution in C. sativa.ResultsBy characterizing the homology between A. lyrata and C. sativa chromosomes, we inferred ancestral diploid karyotype of C. sativa (ADK), including 7 ancestral chromosomes, and reconstructed the evolutionary trajectories leading to the formation of extant C. sativa genome. The process involved 2 chromosome fusions. We found that sub-genomes Cs-G1 and Cs-G2 may share a closer common ancestor than Cs-G3. Together with other lines of evidence from Arabidopsis, we propose that the Brassicaceae plants, even the eudicots, follow a chromosome fusion mechanism favoring end-end joining of different chromosomes, rather than a mechanism favoring the formation circular chromosomes and nested chromosome fusion preferred by the monocots.ConclusionsThe present work will contribute to understanding the formation of C. sativa chromosomes, providing insight into Brassicaceae karyotype evolution.

【 授权许可】

CC BY