SeeDev-binary@ldeleger:SeeDev-binary-21330492-2 JSONTXT

Here, we report that miRNAs are key repressors of the maturation program during embryogenesis. We demonstrate that embryos mutant for strong dcl1 alleles are heterochronic, maturing much earlier than normal. This heterochronic phenotype requires the action of the LEC genes LEC2 and FUS3 downstream of DCL1. We also present the first evidence, to our knowledge, for the repression of maturation during early embryogenesis by ASIL1, ASIL2, and HDA6/SIL1. These genes also act downstream of the miRNA pathway. Our data suggest that one or more miRNA targets sit at the top of the regulatory cascade, controlling both activators and repressors of the embryonic maturation program.