Ancestral Chromosomal Blocks Are Triplicated in Brassiceae Species with Varying Chromosome Number and Genome Size
| Authors | |
|---|---|
| Year of publication | 2007 |
| Type | Article in Periodical |
| Magazine / Source | Plant Physiology |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.plantphysiol.org/content/plantphysiol/145/2/402.full.pdf |
| Field | Botany |
| Keywords | chromosomel painting; genome size; chromosomal evolution; paleopolyploidy |
| Description | Comparative painting analysis of block F of the crucifer Ancestral Karyotype (AK; n=8), consisting of 24 conserved genomic blocks, in 10 species traditionally treated as members of the tribe Brassiceae. Three homeologous copies of block F were identified per haploid chromosome complement in Brassiceae with 2n=14, 18, 20, 32, and 36. In high-polyploid Crambe maritima (2n=60), C. cordifolia (2n=120), and Vella pseudocytisus (2n=68), 6, 12, and 6 copies have been revealed, respectively. In subtribe Zillineae, two of the three homeologous regions were combined via a reciprocal translocation onto one chromosome. Altogether, these findings provide compelling evidence of an ancient hexaploidization event and corresponding whole-genome triplication shared by the tribe Brassiceae. Only two homeologous copies of block F suggest a whole-genome duplication but not the triplication event in Orychophragmus violaceus (2n=24), and confirm its phylogenetic position outside the tribe Brassiceae. |
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