The Nature Of Aberrant Chromosomes In Apomictic Boechera Accessions
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| Year of publication | 2009 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | The only apomicts in the Brassicaceae family reported so far were found in the genus Boechera and occur at the diploid, triploid and tetraploid level. Among the diploids cytotypes with 14 and 15 chromosome complements were found showing a plethora of different forms in chromosome morphology. Chromosome painting with genomic DNA of sexual B. stricta and B. holboellii (or related species) suggests that homoeologous chromosome substitution is common in these apomicts producing accessions with different chromosomes from their putative sexual ancestors. All apomicts studies so far display one or two aberrant chromosomes: a highly heterochromatic chromosome (Het) in the 14 and 15 chromosome accessions and a strikingly small chromosome (Del) in the 15 chromosome accessions. Here we report the analysis of chromosome painting experiments using pooled BACs from gene blocks defined in the sexual B. stricta. Our data showed that the Het chromosome is related to linkage group 1 (LG 1) of B. stricta and that the Del chromosome is a translocation chromosome containing the distal end of the long arm of the Het chromosome. We also confirmed a previously demonstrated translocation in BH224 and trisomy for LG7 in one apomictic 15 chromosome cytotype. The consequences of our chromosome painting for understanding related reports are discussed. |
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