Transposon expression kinetics in Dnmt3L-/- developing testes [RNA-seq]

We examined the kinetics of production of mRNAs and small RNAs derived from transposable elements during mouse spermatogenesis, in whole gonads of wildtype and DNA methylation-deficient males (Dnmt3L and Miwi2 mutants). We found that in absence of DNA methylation, transposon reactivation is not constitutive but rather occurs in a class- and development-specific manner : both the intensity of reactivation and the number of reactivated transposon classes increased as germ cells progress in meiosis. Moreover, we observed that transposon silencing before meiosis is not due to increased cleavage by the piRNA machinery. In contrast, the burst of transposon transcripts occurring at meiosis in the absence of DNA methylation serve as substrates for increased piRNA production Overall design: Six whole testis samples were analyzed, corresponding to three time points (16.5dpc, 10dpp and 20dpp) each for Dnamt3L-/- animals and control littermates. For 16.5dpc, testes from 7/8 mice were pooled per genotype. For the other stages, three mice were pooled per genotype.

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Zamudio N, Barau J, Teissandier A, Walter M, Borsos M, Servant N, Bourc'his D