Three Person IVF
We all get our genetic material from our parents, our bodies are fully composed of genetic material our mother and father passed down to us. Science has found a way to give a child some passable genetic material from three parents. This is known as three person IVF technique. How does it work, read to find out!
What is the need for three person IVF technique?
Scientists developed this technique in order to limit and stop the transfer of defective mitochondrial genes from the mother to the offspring. An embryo or zygote forms at the fusion of the egg from the mother and sperm from the father. The genetic material is provided equally by both parties. Hence, your genetic material is from both your parents. However, the mitochondrial DNA that you have is solely your mother's. Mitochondria are known as the powerhouse of cells, in short, they are the site of oxidative phosphorylation which produces energy for the cell to work. Every cell requires energy to function, your heart cells need it to pump blood, and neurons need it to transfer electric impulses. Mitochondria is one of the organelles that have their own DNA, it is different from the nuclear genetic material. The sperm cell derives energy from mitochondria to reach up to the egg and at the fusion site, loses its tail. The loss of the sperm's tail leads to the loss of mitochondria as well. Hence when sperm fuses with egg, it only transfers nuclear genetic material. The newly formed zygote would have equal nuclear genetic material from both parents. However, the mitochondrial genetic material is inherited from the mother. Hence, your mitochondria are inherited from your mother alone, who inherited from her and furthermore.
The need to invent this technique was because when the faulty mitochondrial DNA was inherited by the zygote, its expression had fatal consequences. To undo this fate, scientists came up with a three-person IVF technique.
What is three person IVF technique?
In this technique, the genetic material is dependent on the mother and father. The physical attributes that a child exhibits as phenotypes are controlled by this material. Hence, the child formed by such a technique only shows physical features inherited from their nuclear parents. To overcome the faulty mitochondrial DNA, a donor egg is used from which healthy mitochondrial genes can be transferred to the zygote. This way, the child will have three biological DNA in them. Nuclear genetic material is inherited from both parents and the mitochondrial DNA from the donor. The mitochondrial DNA is low in amount as compared to the nuclear one.
How is it accomplished?
From the name, it is clear that the technique is in vitro i.e. in an external environment like a laboratory. Mitochondrial transfer techniques work in a few different ways. One of such way is when the nuclear component from the mother's egg is separated from the cell and added to a donor egg where the nuclear component is taken out, it's called an empty egg. After combining these two components, the sperm fertilizes the egg and the zygote is produced. Another way, it can be attained is at the pronuclei stage, where before the fusion of nuclei of gametes, the mitochondrial DNA from the donor is inserted.
This technique is beneficial in erasing inherited mitochondrial diseases and related complications. Some ethical aspects regarding this technique have been put up. This technique is amusing and fascinating in its own way how humans find out a way to beat genetic disease.
References:
https://sitn.hms.harvard.edu/flash/2018/mitochondrial-transfer-making-three-parent-babies/
Farnezi, H.C.M., Goulart, A.C.X., Santos, A. dos, Ramos, M.G. and Penna, M.L.F. (2020). Three-parent babies: Mitochondrial replacement therapies. JBRA Assisted Reproduction, 24(2). doi:https://doi.org/10.5935/1518-0557.20190086.