Akhunov, E.D., Sehgal, S., Liang, H., Wang, S., Akhunova, A.R., Kaur, G., Li, W., Forrest, K.L., See, D., Šimková, H., Ma, Y., Hayden, M.J., Luo, M., Faris, J.D., Doležel, J., Gill, B.S.
PLANT PHYSIOLOGY
161:
252–265,
2013
Klíčová slova:
Abstrakt:
Cycles of whole-genome duplication (WGD) and diploidization are hallmarks of eukaryotic genome evolution and speciation.
Polyploid wheat (Triticum aestivum) has had a massive increase in genome size largely due to recent WGDs. How these processes
may impact the dynamics of gene evolution was studied by comparing the patterns of gene structure changes, alternative
splicing (AS), and codon substitution rates among wheat and model grass genomes. In orthologous gene sets, significantly more
acquired and lost exonic sequences were detected in wheat than in model grasses. In wheat, 35% of these gene structure
rearrangements resulted in frame-shift mutations and premature termination codons. An increased codon mutation rate in
the wheat lineage compared with Brachypodium distachyon was found for 17% of orthologs. The discovery of premature
termination codons in 38% of expressed genes was consistent with ongoing pseudogenization of the wheat genome. The
rates of AS within the individual wheat subgenomes (21%–25%) were similar to diploid plants. However, we uncovered a
high level of AS pattern divergence between the duplicated homeologous copies of genes. Our results are consistent with the
accelerated accumulation of AS isoforms, nonsynonymous mutations, and gene structure rearrangements in the wheat lineage,
likely due to genetic redundancy created by WGDs. Whereas these processes mostly contribute to the degeneration of a
duplicated genome and its diploidization, they have the potential to facilitate the origin of new functional variations, which,
upon selection in the evolutionary lineage, may play an important role in the origin of novel traits.
Fulltext: kontaktujte autory z ÚEB
Autoři z ÚEB: Jaroslav Doležel,
Hana Šimková
Čeština
English