Parent‐of‐origin control of transgenerational retrotransposon proliferation in Arabidopsis

Abstract

Retrotransposons are ubiquitous mobile genetic elements constituting a major part of eukaryotic genomes. Yet, monitoring retrotransposition and subsequent copy number increases in multicellular eukaryotes is intrinsically difficult. By following the transgenerational accumulation of a newly activated retrotransposon EVADE (EVD) in Arabidopsis, we noticed fast expansion of activated elements transmitted through the paternal germ line but suppression when EVD-active copies are maternally inherited. This parent-of-origin effect on EVD proliferation was still observed when gametophytes carried mutations for key epigenetic regulators previously shown to restrict EVD mobility. Therefore, the main mechanism preventing active EVD proliferation seems to act through epigenetic control in sporophytic tissues in the mother plant. In consequence, once activated, this retrotransposon proliferates in plant populations owing to suppressed epigenetic control during paternal transmission. This parental gateway might contribute to the occasional bursts of retrotransposon mobilization deduced from the genome sequences of many plant species.

Transcriptional control and exploitation of an immune‐responsive family of plant retrotransposons

“…ATCOPIA93 has been a widely used model to study plant transposon biology and epigenetics over the last years (Mirouze et al, 2009;Tsukahara et al, 2009Tsukahara et al, , 2012Marí-Ordóñez et al, 2013;Reinders et al, 2013;Rigal et al, 2016;Oberlin et al, 2017). However, with the exception of DNA methylation-defective mutants, the conditions required for the activation of this family, have not been fully explored.…”

Transgenerational Epigenetic Inheritance: Myths and Mechanisms

“…As mCHH is guided by small RNA this allows for reprogramming of this epigenetic mark after fertilization (Jullien et al, 2012), when the majority of 24nt heterochromatic siRNA is provided by the maternal genome (Mosher et al, 2009). This results in transgenerational maternal silencing of otherwise active retrotransposons by RNA guided DNA methylation (Mari-Ordonez et al, 2013; Reinders et al, 2013), and may be related to “self-non-self” distinction in Tetrahymena , C. elegans and Drosophila (Brennecke et al, 2008; Chalker and Yao, 2011; de Vanssay et al, 2012; Shirayama et al, 2012). …”

Differential introgression and reorganization of retrotransposons in hybrid zones between wild wheats

“…To what extent LTR-RTs drive preferential backcrossing towards the maternal parent, as here observed in hybrid zones between wild wheats, remains a largely open question. Available evidence indicates that cytoplasmic repressors control conflicting interactions between LTR-RTs across multiple generations (Reinders et al 2013), suggesting that they may add to conventional nucleo-cytoplasmic incompatibilities at specific loci as mechanisms supporting unidirectional introgression (Cruzan & Arnold 1999). Additional work is necessary to demonstrate the consistent relevance of LTR-RT-related dysgenesis in promoting the assimilation of hybrids back into their parental genetic backgrounds and the long-term maintenance of stable species with permeable boundaries (Rieseberg & Wendel 1993).…”