Scientists discover new DNA modification system in animals, captured from bacteria more than 60 MYA

epigenetic marks can be made by adjusting the design of your body.

Epigenetic marks are modifications to DNA bases that don't change the underlying genetic code, but they can be written on top of it to give you more information. Epigenetic marks regulate the expression of genes, particularly during early development or when your body is under stress. Transposable elements that threaten the integrity of your genome can be suppressed by them.

There are two main epigenetic marks in humans. A third novel epigenetic mark has been discovered by a team from the Marine Biological Laboratory. This discovery is reported this week in Nature Communications.

The senior scientist in the Josephine Bay Paul Center said that they discovered in 2008 that bdelloid rotifers are good at capturing foreign genes.

It has not been previously reported, andHorizontally transferred genes are thought to be operational genes. The existing regulatory systems are already very complicated, so it is hard to imagine how a single, horizontally transferred gene would form a new regulatory system.

It is almost unbelievable, said co-first author Irina Yushenova, a research scientist in Arkhipova's lab. The rotifer had two of them join in its genome and form a functional enzyme. That is not easy to do in the lab, and it happened naturally. The bdelloid rotifers were able to control all the jumping transposons with the help of the regulatory system created by the composite enzyme. It is like magic.

Fernando Rodriguez is a research scientist in Arkhipova's lab. Different animals have different epigenetic systems to accomplish that. A new epigenetic system in animals that hasn't been described before was created by a horizontal gene transfer frombacteria into bdelloid rotifers.

Arkhipova said that bovine rotifers have to keep their transposons in check because they reproduce asexually. The transposon content in bdelloids is lower than it is in sexual organisms that do not have this epigenetic layer.

In the two previously known marks, a methyl group is added to a DNA base. The new mark is a modification of the cytosine that recapitulates evolutionary events that took place over two billion years ago.

Over the years, the Arkhipova and David Mark Welch labs at MBL have discovered that bdelloid rotifers are extremely resilient. They can dry up for weeks or months at a time, and then come back to life when water becomes available. When they rehydrate or otherwise render their DNA ends accessible, this might be an opportunity for foreign DNA fragments from ingestedbacteria, fungi, or microalgae to transfer into the rotifer genome. They have found that 10 percent of the rotifer genome comes from non-metazoan sources.

The Arkhipova lab was surprised to find a gene in rotifer that was similar to a bacterial methyltransferase.

It is too early to know what the implications will be of discovering this new epigenetic system in rotifers. Rodriguez said that the tool for gene editing in other organisms is now used everywhere. Will it have implications for future research? It is hard to tell.

The discoveries open the door to new tools and research directions to investigate the function and resilience of the rotifer system. During this time of rapid environmental change, knowledge may be applied in creative ways to impact society.

More information: Bacterial N4-methylcytosine as an epigenetic mark in eukaryotic DNA, Nature Communications (2022). Journal information: Nature Communications Citation: Scientists discover new DNA modification system in animals, captured from bacteria more than 60 MYA (2022, February 28) retrieved 28 February 2022 from https://phys.org/news/2022-02-scientists-dna-modification-animals-captured.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.