|By Tyler MacDonald | 9 months ago|
Nearly half of the DNA sequences in our body are created from jumping genes, also called transposons. These genes jump around our genome in developing egg and sperm cells are are crucial to our evolution. However, mobilization can lead to new mutations that eventually cause diseases like cancer and hemophilia.
Now, a team of researchers has created unique techniques to track the mobilization of these jumping genes. They also discovered that during a specific egg development period, a group of these genes called retrotransposons hijacks cells called nurse cells, which in turn nurture growing eggs.
“We were very surprised that the these jumping genes barely moved in stem cells that produce developing egg cells, possibly because the stem cells would only have two copies of the genome for these jumping genes to use,” said co-author Zhao Zhang. “Instead, these moving elements used the supporting nurse cells, which could provide up to thousands copies of the genome per cell, as factories to massively manufacture virus-like particles capable of integration.”
But the genes did not combine into the nurse cells where they were created, instead waiting while they were taken to an interconnected egg cell. After this point, they added anywhere from hundreds to thousands of new clones of themselves into the egg DNA.
“Our research shows how parasitic genetic elements can time their activity and distinguish between different cell types to robustly propagate to drive evolutionary change and cause disease,” said Allan Spradling, co-author of the study.
The findings were published in Cell.