From now on we will have to start being more aware of our life habits, because according to a study published in Cell, they are transmitted to our offspring.
The team led by Juan Carlos Izpisúa, from the Salk Institute for Biological Studies in La Jolla (California, USA) and a professor at the Catholic University of Murcia (UCAM), has shown in mammals that epigenetic marks acquired at different points in the genome by interaction with the environment are transmitted to their offspring.
The research marks a milestone in the controversy between Darwin’s and Lammark’s theories. One of the most important debates in the history of biology, and one that has helped enormously to explain the causes of evolution, is the confrontation between the theory of natural selection of Darwin with Lammarck’s theory of the heritability of acquired characteristics, whose postulate argued that each organism changes during life to adapt to its environment and that these changes are transmitted to its offspring.
The article demonstrates, for the first time, in mammals, that epigenetic marks acquired for different reasons in some areas of the genome are transmitted to offspring and in multiple generations, as are their associated phenotypic traits. In this case, the DNA methylation in CpG islands associated with the promoters of two genes related to metabolism, Ldlr and Ankrd, and which is associated with hypercholesterolemia and obesity, respectively, has been studied in mice.
According to Izpisúa, “the development of this study has taken us more than 10 years of work and demonstrates the importance that the environment can have, through epigenetics, on the future of our lives and those of our descendants.”
To carry out this study, the researchers generated obese and hypercholesterolemia mice through methylation of the CGI promoters of the Ankrd and Ldlr (low-density lipoprotein receptor) genes, thus causing their silencing. These methylations occur naturally based on each individual’s eating habits or lifestyle and do not affect their gene sequence. With this model, they were able to observe in the offspring of the mice how the epigenetic changes (methylations) produced by gene editing were transmitted to the offspring over several generations, giving rise to obese mice with hypercholesterolemia.
«This work in itself constitutes a methodological milestone. which will undoubtedly be an important tool for the study of epigenetics in general. In this case, it has allowed us to present the first direct evidence that epigenetic information can be stably transmitted to offspring through the paternal and maternal germ lines,” says Estrella Núñez, UCAM Vice-Rector for Research and co-author of the article.
These observations provide the first evidence for transgenerational epigenetic inheritance in mammals. These insights will have implications for the role epigenetic inheritance plays in biological macroevolution, as well as in mammalian embryogenesis.
“These rodent studies, if proven in clinical trials, will help us better understand the etiology, diagnosis, and susceptibility of offspring to non-genetically inherited human diseases, such as hereditary susceptibility to cancer, cardiovascular disease, neurodegenerative disease, and obesity», adds Izpisúa.