How is epigenetics used in the differentiation of cells and is this the only thing that is used? I've seen that transcription factors play a role but are these simply proteins that initially write the epigenetic code or something different altogether?
I've written this explanation of how I understand it currently. Please tell me if this is right or wrong.
How do our cells become specialised if they have the same genome? The answer lies in the fact that gametes have most of their epigenetic information taken off at fertilisation, (apart from small sections like at IAP retrotransposons) so it’s like a clean slate. The zygote cells divide to form many identical cells that have the capacity to become any cell in the body. Proteins in the egg then bind to certain genes and regulate their expression by adding epigenetic markers like methyl groups and histone modifications. The proteins created from these genes then go to control the regulation of other genes and so on, until all the cells have different epigenetic markers put on them that mean they produce different proteins in different quantities to serve different functions in the body.