ChIP-seq: Embryos were collected, fixed in formaldehyde, chromatin was isolated, and the chromatin was immunoprecipitated as described in Li et al., 2008. Immunoprecipitation was done using two antibodies against Grainy head and an input sample was also collected for sequencing. RNA-seq: Embryos depleted of either maternal or zygotic GRH as well as sibling controls were collected and examined to determine the stage. 7 embryos were collected for each set and lysed in TRIzol reagent (Life Technologies) supplemented with 150 µg/ml glycogen. RNA was extracted and cDNA libraries were prepared using the Illumina Truseq RNA sample prep kit. ChIP-seq libraries were prepared using standard Illumina protocols and RNA-seq libraries were prepared using Illumina Truseq RNA sample prep kit according to manufacterer's instructions