Histones, the powerful regulators of the nucleus that can make our genetic material expand and contract faster than interest rates on the economy, are deeply involved in stem cell differentiation dynamics.
But what about the total amount of histones in a cell? Until recently researchers have viewed histone content as fairly fixed, but an Italian team of researchers led by Theodoros Karnavas decided to take a closer look at total histone composition and its dynamics in ESCs.
Since core histones are generally present at stoichiometric amounts, the team decided to study histone H3 as it could be used as a good representative of all core histones.
In their approach, the team:
- Quantified histone H3 mRNA with qRT-PCR and compared those with ribosomal RNA 28S as a normalizer
- Next, the team looked at the levels of histone H3 protein relative to the total DNA content
- They found and 8-fold increase in histone content in mouse embryonic Fibroblasts (being more differentiated) compared to ESCs.
This estimation of actual histone content has highlighted an interconnection between histone content and histone modification provides additional visibility into the epigenetic landscape of ESCs.
Although, analyzing specific histone mark patterns in differentiation has been a fruitful approach thus far, this work definitely encourages researchers to consider histone content as a key factor in ES cell maintenance and differentiation.
Want more content? Check out the full details at Front Physiol. 2014