Monday, November 13, 2017 by Russel Davis
A recent animal study published in the Science journal has revealed that genetic changes caused by environmental factors may be passed down from one generation to another. According to a team of researchers at the European Molecular Biology Organisation (EMBO) in Spain, the genetic changes may even be inherited by up to 14 generations thereafter. The experts have examined the genetically engineered nematode roundworms called C. elegans in order to carry out the study. The roundworms are known to carry a specific gene that makes them glow bright under ultraviolet light once it is activated.
The research team initially changed the temperature of the animals’ containers to 68 degrees Fahrenheit. The experts have observed that the gene reduced activity, and that the nematodes hardly glowed at all. The scientists have then transferred the worms to a warmer temperature of 77 degrees Fahrenheit. This resulted in the activation of the fluorescence gene that made the worms glow like Christmas lights. The experts have also observed that the worms continued to glow when they were moved back to a colder temperature.
The scientists also examined the worms’ offspring for up to seven generations and found that the baby worms appeared to have inherited the epigenetic genes for a warmer climate despite not being exposed to such temperature changes. The research team has assessed the animals further by exposing five generations of nematodes at 77 degrees Fahrenheit and then exposing the other half of their offspring to colder temperatures. The results have shown that both groups exhibited high fluorescence gene activity. The mechanism behind the worms’ response remains unclear, but it appears that the effects might be a type of biological forward-planning, researcher Adam Klosin has reported.
Past studies have long established that the effects of lifestyle choices of a precedent generation may manifest in the generations that follow. In fact, a study carried out by researchers at the Chinese Academy of Sciences has indicated that a parent’s unhealthy eating behaviors may be recorded by a tsRNA molecule and can be passed on to the offspring through sperm to the embryo.
According to researchers, the tiny molecule is produced by a parent who adopts a fatty diet and suffers from obesity. The scientists have noted that the molecule may well predispose an offspring into consuming large amounts of glucose, which in turn may raise the odds of developing an insensitivity to insulin. (Related: Researchers want to genetically modify humans in supposed “cure” for obesity.)
“In the fields of infant nutrition, diabetes, obesity, and the metabolic syndrome, the term “metabolic programming” has been coined to give a name to the observation that environmental experiences early in life may be “genomically” remembered and give rise to health outcomes manifesting later in life. Epigenetics emerges as an important mechanism underlying this phenomenon,” the researchers have concluded.
Another animal study has revealed that an aversion to certain factors such as odor can be passed down from one generation to another. As part of the study, a team of scientists at the Emory University School of Medicine has trained mice models to fear a smell that is reminiscent of cherry blossom. The researchers have also examined the mice’s sperm samples and observed an increased activity in a DNA section that plays a key role in odor sensitivity.
The results have shown that the animals’ aversion to the scent was inherited by their grandchildren. The experts have also identified certain changes in the animals’ brain structures. According to the research team, this suggests that a parent’s previous experiences may influence the nervous system structure and function of the succeeding generations.
“[The findings were] highly relevant to phobias, anxiety and post-traumatic stress disorders. It is high time public health researchers took human transgenerational responses seriously. I suspect we will not understand the rise in neuropsychiatric disorders or obesity, diabetes, and metabolic disruptions generally without taking a multi-generational approach,” says Professor Marcus Pembrey of the University College London.