March 3, 2023
Keio University School of Medicine
A research group led by Assistant Professor Akihiko Sakashita, Tomohiro Kitano (a fourth-year student in the Doctoral Programs at the Graduate School of Medicine), Senior Lecturer Hidetoshi Ishizu, and Professor Haruhiko Shiomi of the Department of Molecular Biology, Keio University School of Medicine, has developed a multi-copy gene analysis technology that targets ancient viral fossils scattered throughout the mammalian genome. They revealed that the loss of function of MERVL—which is derived from a virus that caused infection over 70 million years ago and has evolved uniquely within the mouse genome—causes defects in normal individual development.
It was previously known that MERVL, a type of endogenous retrovirus, is specifically highly expressed in mouse embryos immediately after fertilization, which have the ability to differentiate into all cells of the body (totipotency). However, due to the difficulty of targeting and analyzing MERVL, which exists in over 1,000 copies in the genome, its expression was concluded to be merely a "marker of totipotency," and the pursuit of its functional significance has been largely neglected. Therefore, in this study, we developed a multi-copy gene analysis technology to efficiently target MERVL scattered across the genome and revealed that MERVL plays an essential role in mouse individual development. These findings contribute to the understanding of the complex and diverse individual development of mammals from the new perspective of host genome regulation by species-specific viral fossils. The results of this research were published in the online edition of Nature Genetics on March 2, 2023 (US Eastern Standard Time).
For the full press release, please see below.