Comparative genomics of apomictic root-knot nematodes: hybridization, ploidy, and dynamic genome change
Szitenberg, Amir; Salazar-Jaramillo, Laura; Blok, Vivian C.; Laetsch, Dominik R.; Joseph, Soumi; Williamson, Valerie M.; Blaxter, Mark L.; Lunt, David H.
Vivian C. Blok
Dominik R. Laetsch
Valerie M. Williamson
Mark L. Blaxter
Dr Dave Lunt D.H.Lunt@hull.ac.uk
The Root-Knot Nematodes (RKN; genus Meloidogyne) are important plant parasites causing substantial agricultural losses. The Meloidogyne incognita group (MIG) of species, most of which are obligatory apomicts (mitotic parthenogens), are extremely polyphagous and important problems for global agriculture. While understanding the genomic basis for their variable success on different crops could benefit future agriculture, analyses of their genomes are challenging due to complex evolutionary histories that may incorporate hybridization, ploidy changes, and chromosomal fragmentation. Here we sequence 19 genomes, representing five species of key RKN collected from different geographic origins. We show that a hybrid origin that predated speciation within the MIG has resulted in each species possessing two divergent genomic copies. Additionally, the apomictic MIG species are hypotriploids, with a proportion of one genome present in a second copy. The hypotriploid proportion varies among species. The evolutionary history of the MIG genomes is revealed to be very dynamic, with non-crossover recombination both homogenising the genomic copies, and acting as a mechanism for generating divergence between species. Interestingly, the automictic MIG species M. floridensis differs from the apomict species in that it has become homozygous throughout much of its genome.
|Journal Article Type||Article|
|Publication Date||Oct 1, 2017|
|Journal||Genome biology and evolution|
|Publisher||Oxford University Press (OUP)|
|Peer Reviewed||Peer Reviewed|
|APA6 Citation||Szitenberg, A., Salazar-Jaramillo, L., Blok, V. C., Laetsch, D. R., Joseph, S., Williamson, V. M., …Lunt, D. H. (2017). Comparative genomics of apomictic root-knot nematodes: hybridization, ploidy, and dynamic genome change. Genome Biology and Evolution, 9(10), 2844-2861 . https://doi.org/10.1093/gbe/evx201|
|Keywords||Meloidogyne; coverage ratio; genome evolution; phylogenomics; recombination|
|Additional Information||This is a copy of an open access article published in Genome biology and evolution, 2017.|
© The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.