They discover the importance of “selfish” DNA in human development.

Transposons are DNA sequences that can move around within the genome, sometimes causing mutations, but also play an important role in gene regulation and development.

This discovery, published in the journal Developmental Cell, challenges our previous understanding of these elusive DNA segments, shedding new light on the role they play in human development and disease.

For years, scientists believed that these elements were mostly harmful, sometimes damaging the genome and contributing to the development of diseases ranging from hemophilia to neurological disorders and cancer.

“There is a tendency to think that transposons are something like viruses that take over our cells for the sole purpose of spreading,” explains study co-author Miguel Ramalho-Santos, the principal investigator. “We found that these elements are not simply genomic parasites, but are essential for early development,” adds Ramalho-Santos.

This discovery has potential applications in fertility treatments and regenerative medicine, and opens new avenues for studying its involvement in diseases such as cancer and neurological disorders.

The scientists found that inhibition of LINE-1 in embryonic stem cells causes regression to a primitive phase, demonstrating its importance in cell specialization.

Regenerative medicine

The results show that these genetic elements not only help organize DNA within the nucleus, but also play a key role in normal embryonic development.

The research has important implications for the treatment of infertility and the use of stem cells in regenerative medicine. In addition, this work reveals new functions of LINE1, which can now be explored in the pathological contexts in which it is involved, from neurological disorders to cancer.

Anne-Claude Gingras, director of LTRI and vice president of research at Sinai Health, notes that “the study shows how much remains to be learned not only about human development, but also about these mysterious elements of the genome whose functions are simply ‘They’re starting to emerge’.” .