Researchers at the John Innes Research Center have discovered a mechanism that allows the germ cells in flowering plants to remain immortal. The article of scientists was published in the journal Nature Genetics. This was announced in a press release on the EurekAlert! Website.
Germ cells pass on their genetic material to the next generations, and they are not limited by the Hayflick limit, which indicates how many times a somatic cell can divide, after which it dies. The germ cells give rise to gametes, which, in turn, enable the embryo to emerge. Embryonic cells divide and differentiate to form plant tissues and organs, as well as new germ cells.
It was believed that plant cells are reprogrammed every time with the help of epigenetic factors - molecules that change the activity of genes without introducing mutations into the DNA. However, there was no evidence that this process actually took place.
The researchers showed that methylation occurs in the germ cells of the Arabidopsis thaliana plant, during which a methyl group is attached to the cytosine in the CpG dinucleotide, a DNA segment consisting of cytosine and guanine. In this case, reprogramming in each generation proceeds anew, although it is known that in plants epigenetic settings can be preserved in offspring. According to scientists, the renewal of the gene regulation system is an important condition for the stable functioning of germ cells.