Researchers at Tel Aviv University (TAU) say they have found a mechanism in nematodes – worms that are found in all environments. The mechanism allows neurons or brain cells to transmit information for generations and control the offspring of organisms, writes the Times of Israel.
The results indicate that brain activity, and not just the information contained in the DNA, may play a role in what our children inherit.
According to the researchers, it is not yet known whether any of the work on the nematodes, also called roundworms, can be transmitted to humans.
The researchers’ findings go against one of the fundamental dogmas of modern biology – “the second law of biology”, which states that only sperm and eggs affect inherited traits and that the neuron’s influence on human behavior is not hereditary. Hereditary information is thus believed to be isolated from environmental influences. p>
This may mean that the nervous system, which is unique in its ability to plan and organize responses to both environmental and internal influences, can help future generations of offspring.
Researchers have shown in their study that the worms’ nervous system controlled their offspring’s ability to look for food.
The discovery could have major implications for our understanding of heredity and evolution, said Prof. Oded Rechavi of TAU’s George S. Wise Faculty of Life Sciences and Sagol School of Neuroscience, who led the study. The study was published in the journal Cell on Thursday.
According to the study’s co-authors – Rechavi’s students Rachel Posner and Itai Toker, this is the first time a mechanism has been identified that can transmit neuronal responses – or brain activity – across generations.
The research also found the way in which neurons send messages to future generations: via small RNA molecules, whose role is to regulate the function of genes.
The researchers found that RNA molecules transfer information from parental neurons to the offspring by regulating the genes in the germ cells (sperm and eggs) and thus controlling the expression of many genes. It leads to changes in the physiological processes of the organism in development. In particular, inheritance is affected by small RNAs that are controlled by the nervous system, which even after three generations will affect the search for food in the offspring.
A ‘Holy Grail’
“We’ve learned a lot about the transgenerational inheritance of small RNAs in worms in the last few years,” Toker said. “But the discovery of a transgenerational transfer of information from the nervous system is a holy grail.”
“The nervous system is unique in its ability to integrate responses to both environmental and bodily responses. The idea that it can also control the fate of the organism’s offspring is amazing,” he said.
In their research, the researchers discovered that the synthesis of small RNAs in neurons is necessary for the worm to be effectively attracted to odors associated with essential nutrients – to look for food.
The small RNA control genes, including a gene called saeg-2, which are necessary for the nervous system to function properly and to generate movement towards food after the smell of food is perceived.
The researchers found that it is the small RNAs produced in the parents’ nervous system that influence the behavior of their offspring..
In other words, nematodes that could not produce small RNAs in their neurons showed defective food identification skills. However, as the researchers corrected the ability to produce small RNAs in neurons, the nematodes regained their food identification skills.
However, the most interesting finding was that worms that originated from ancestors and had the small RNAs had the ability to find food – even if they did not produce small RNAs themselves. And the effect was maintained for generations.
“If the results can be translated into humans,” and we do not know if they can, then it will change the way we understand heritage, “Rechavi said.
“Many traits can be influenced by factors that are epigenetic – that is, not inherited by DNA. Deeper understanding of unconventional forms of inheritance can prove crucial to better understand the conditions and to design better diagnostics and perhaps also treatments. , “he said in an interview.
Toker added that further studies might check whether specific neuronal activities could affect the inherited information in a way that would provide specific benefits to the offspring.
“Potentially, parents will be able to transfer information that would be beneficial to the offspring,” and therefore potentially affect “an organism’s evolutionary route,” he said.