How much information in a cell (human zygote)?

[Mr Skeptic]

According to wikipedia,

The 3 billion base pairs of the haploid human genome correspond to an information content of about 750 megabytes. The entropy rate of the genome differs significantly between coding and non-coding sequences. It is close to the maximum of 2 bits per base pair for the coding sequenes (about 45 million base pairs), and between 1.5 and 1.9 bits per base pair for each individual chromosome, except for the Y chromosome, which has an entropy rate below 0.9 bits per base pair.

 

In other words, we could store a copy of our genome on a CD.

 

Despite having put this in the genetics forum, what I'm interested in is how much information is contained in the cell itself other than in the DNA sequence. In particular, that of a fertilized human egg cell. I'm not interested in the information necessary to copy a specific cell right to the atom, rather in how much information is needed to specify a cell able to develop into an adult human.

 

For example, genes can be methylated. Since we have 20,000-25,000 genes and each could at most have equal chance of being methylated or not, that would be an extra 25,000 bits maximum from the methylation. Obviously the true value would be much lower, but if we can't have exact numbers a maximum or a guestimate would be OK.

 

Another example would be the protein arrangements and gross structure of the cell; unfortunately I have no clue how much information is required to describe these.