“We provided functional evidence that transcriptional activation of MERVL is essential for progression of development in mouse preimplantation embryos. Depletion of MERVL transcripts [retrotransposons] results in embryonic lethality with profound defects in development and is associated with dysregulation of MERVL including their adjacent transcripts, and retaining two-cell-like transcriptome and chromatin state (Fig. 6i). These findings suggest the possibility that MERVL transcription in totipotent cells may act as a switch for the transition from totipotency to pluripotency and is responsible for the onset of differentiation and ontogeny.” – Akahiko Sakashita et al. (March 2, 2023)
The paper is open access.
One Reply to “Junk DNA has yet another job – keeping mouse embryos alive”
Transposons are the stuff of Dawkin’s famous “selfish genes,” genes that are like parasites, that reproduce themselves for the sake of themselves and not the organism. And now, they embryo can’t live without them? Essential function? Could evolutionary biology have been wrong? Say it isn’t so.
Here’s a little something:
A pivotal transformation in TE biology occurred less than 10 years after the publication of the Human Genome Project. Next-generation sequencing has empowered researchers to interrogate longstanding and previously intractable questions regarding TE biology [7, 10, 11]. Examples include the frequency and location of new insertions and the contribution of TEs to gene regulation genome-wide at an unprecedented resolution [8, 9, 12, 13]. New studies will likely unveil novel ways by which these selfish genetic elements may actually be altruistic or even co-opted by the host genome  along with new insights into mechanisms by which they can cause disease.