Maternal to zygotic transition

The egg contains stored maternal genetic material mRNA which controls embryo development until the onset of MZT.

[3] Cellular functions during early cleavage are carried out primarily by maternal products – proteins and mRNAs contributed to the egg during oogenesis.

[7] Evidence for the first method was provided by Newport and Kirschner's experiments showing that nucleocytoplasmic ratio plays a role in activating zygotic transcription.

[5][8] More recently, evidence has been shown that transcription of a subset of genes in Drosophila is delayed by one cell cycle in haploid embryos.

Prioleau et al. show that by introducing TATA binding protein (TBP) into Xenopus oocytes, the block in transcription can be partially overcome.

[11] The generally accepted mechanism for the initiation of embryonic gene regulatory networks in mammals is the occurrence of multiple waves of MZT.