Gene Expression during Development

Gene Expression during Development
Early embryonic development is directed by products synthesized during oogenesis and stored in the egg. After fertilization, proteins are translated from stored mRNA which was transcribed from the maternal genome. In many animals, maternal mRNA directs protein synthesis through cleavage and to the early or mid-blastula stage. After this stage, protein synthesis gradually switches from maternal to zygotic control as descendants of the zygote nucleus begin to transcribe their own mRNA.