University of Heidelberg, Centre for Organismal Studies, Laboratory of Germline Genetics & Evo-Devo, Heidelberg, Germany.
Jacobs University, Life Sciences & Chemistry, Laboratory of Germline Genetics & Evo-Devo, Bremen, Germany.
Sci Rep. 2018 Jul 13;8(1):10626. doi: 10.1038/s41598-018-27863-7.
Genomic imprinting confers parent-of-origin-specific gene expression, thus non-equivalent and complementary function of parental genomes. As a consequence, genomic imprinting poses an epigenetic barrier to parthenogenesis in sexual organisms. We report aberrant imprinting in Boechera, a genus in which apomicts evolved from sexuals multiple times. Maternal activation of a MADS-box gene, a homolog of which is imprinted and paternally expressed in the sexual relative Arabidopsis, is accompanied by locus-specific DNA methylation changes in apomicts where parental imprinting seems to be relaxed.
基因组印记赋予了亲源特异性的基因表达，从而使亲本基因组具有非等同且互补的功能。因此，基因组印记对有性生物的孤雌生殖构成了一种表观遗传障碍。我们在拟南芥的亲缘植物 Boechera 中发现了异常的印记现象，该属中的无融合生殖植物多次从有性生殖植物进化而来。MADS-box 基因的母源激活伴随着特定基因座的 DNA 甲基化变化，而该基因的同源基因在有性相对的拟南芥中被印记并父源表达，这表明在无融合生殖植物中亲本印记似乎被放松了。
