An epigenetic study from the Center for Integrative Health Sciences has shown that mice eggs contain information about DNA that will be inherited from the mother.
Researchers led by Azusa Inoue of the Center for Integrative Health Sciences in Japan have discovered a trace left in unfertilized eggs that determines which DNA modifications will be inherited if the egg is fertilized.
In particular, they found that without the initial modifications of histone H2A in lysine 119, also called H2AK119ub1, late inherited modifications would not occur. One of the consequences of this deficiency was an increase in the placenta after embryo implantation.
The structure of DNA in chromosomes is powered by proteins called histones. When histones are modified, they can change the way genes are expressed in the body. For example, Inoue and colleagues’ previous research showed that acquired histone H3 trimethylation at lysine 27 in mammalian oocytes could be inherited. In a new study, the team decided to figure out how this happens.
First, the researchers examined the periods of two different histone modifications. They found that every gene that exposed H3K27me3 also showed H2AK119ub1 in mouse eggs. The scientists considered this protein important and removed the proteins that make up H2AK119ub1 in the eggs.
As a result, the eggs had much less H3K27me3 than usual. This means that H2AK119ub1 acts as a kind of marker that determines where the next H3K27me3 should be.