de Tomás Carlos, Bardil Amélie, Castanera Raúl, Casacuberta Josep M, Vicient Carlos M
Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, Campus UAB, Edifici CRAG, Bellaterra, Barcelona 08193, Spain.
Institut écologie et environnement (INEE), CNRS, Montpelier, France.
Hortic Res. 2022 May 26;9:uhac127. doi: 10.1093/hr/uhac127. eCollection 2022.
Hybridization has been widely used in breeding of cultivated species showing low genetic variability, such as peach (). The merging of two different genomes in a hybrid often triggers a so-called "genomic shock" with changes in DNA methylation and in the induction of transposable element expression and mobilization. Here, we analysed the DNA methylation and transcription levels of transposable elements and genes in leaves of and and in an F1 hybrid using high-throughput sequencing technologies. Contrary to the "genomic shock" expectations, we found that the overall levels of DNA methylation in the transposable elements in the hybrid are not significantly altered compared with those of the parental genomes. We also observed that the levels of transcription of the transposable elements in the hybrid are in most cases intermediate as compared with that of the parental species and we have not detected cases of higher transcription in the hybrid. We also found that the proportion of genes whose expression is altered in the hybrid compared with the parental species is low. The expression of genes potentially involved in the regulation of the activity of the transposable elements is not altered. We can conclude that the merging of the two parental genomes in this x hybrid does not result in a "genomic shock" with significant changes in the DNA methylation or in the transcription. The absence of major changes may facilitate using interspecific peach x almond crosses for peach improvement.
杂交已广泛应用于遗传变异性低的栽培物种育种，如桃（）。杂种中两个不同基因组的融合通常会引发所谓的“基因组冲击”，导致DNA甲基化变化以及转座元件表达和移动性的诱导。在此，我们使用高通量测序技术分析了[具体物种1]和[具体物种2]叶片以及一个F1杂种中转座元件和基因的DNA甲基化和转录水平。与“基因组冲击”的预期相反，我们发现杂种中转座元件的DNA甲基化总体水平与亲本基因组相比没有显著变化。我们还观察到，杂种中转座元件的转录水平在大多数情况下与亲本物种相比处于中间水平，并且我们未检测到杂种中转录水平更高的情况。我们还发现，与亲本物种相比，杂种中表达发生改变的基因比例较低。潜在参与转座元件活性调控的基因表达没有改变。我们可以得出结论，在这种[具体物种1]×[具体物种2]杂种中，两个亲本基因组的融合不会导致DNA甲基化或转录发生显著变化的“基因组冲击”。没有重大变化可能有助于利用种间桃×杏杂交来改良桃子。
