What Triggers Gene Expression In Embryos
How the combination of an egg and a sperm eventually lead to creating unique and healthy individuals is something that confounds most ordinary people.
How does the combination of maternal and paternal genes end up working together to create life? If you’ve ever wondered about human creation in the earliest stages of development, you aren’t alone.
Today, research is shedding light on embryonic development and the delicate and intricate processes associated with it.
The more this research advances, the more information researchers and doctors have to combat problems with infertility and genetic diseases.
Zygotic Genome Activation
Let’s start from the beginning. What exactly is a zygote? A zygote is a cell that’s formed from the union of an egg and a sperm cell. The fertilized egg that the baby will develop from is a zygote.
Once the cell has divided a few times, each zygote will then carry a copy of the mother and father’s genomes. In humans, a zygote stage of development will begin on the first day of the week following successful fertilization.
What causes this whole process to take place? Until recently, it was unknown. Researchers now know, however, that this process is triggered by zygotic genome activation.
The developing embryo is encouraged to begin the gene expression program through proteins belonging to the DUX family.
This discovery is important as it can lead scientists and researchers to discover more about successful zygotic genome activation.
The more we know about how to successfully create human life, the more we know about fertility treatments, gene expression, and how we work at the earliest and most basic levels.
The DUX4 Protein
The DUX protein’s relationship to zygotic genome activation gained traction when researcher Alberto de Iaco, a postdoc in the lab of Didier Trono at EPFL, was studying patients with muscular dystrophy.
In his research, de Iaco was investigating where various mutations in patients caused production in muscle cells of DUX4 protein. This protein is typically only seen within the early stages of the development of a human embryo.
De Iaco’s research dug into this idea further, exploring if this DUX4 protein was forcibly placed into muscle cells, what would happen? It turns out that when DUX4 is produced in muscle cells, it activates a new set of genes.
These genes are expressed during the zygotic genome activation process (as in early embryonic development). This suggests that DUX4 protein is a primary player at the beginning of human development.
Once they understood DUX4’s relationship to zygotic genome activation, de Iaco and his team moved on to testing and verifying their findings.
If they were on the right path, the implications could be huge for fertility treatments and genetic research related to muscular dystrophy.
De Iaco and his team then needed to verify their findings to further solidify their research regarding DUX proteins and zygotic genome activation.
The team first investigated public data to help gain further insights into what parts of the human genome are expressed during those first crucial moments of embryonic development.
As the researchers suspected, the DUX4 protein was present as one of the first genes to be expressed in the development state.
As it turns out, DUX4 releases a large concentration of protein, which seems to spur and encourage the start of zygotic genome activation.
As with many studies, the next step was to test this theory on mice. De Iaco’s team again confirmed that the DUX4 protein works like a top regulator tasked with igniting genome expression.
The team suspects this to be true of humans, mice, and potentially all placental mammals.