RNA was harvested using Simultaneous Purification of Genomic DNA and total RNA from Animal and Human Cells from the AllPrep DNA/RNA Micro Handbook (QIAGEN, USA). Each 9 samples consist of a pool of 9 to 11 embryos. Enrichement of mRNA was performed using the NEBNext Poly(A) mRNA Magnetic Isolation Module (E7490, New England Biolabs, USA) and libraries were prepared using the NEBNext Ultra II RNA Library kit for Illumina (E7770, E7775, New England Biolabs, USA).