Mitochondrial is a cell organelle, which provides required energy to do their work. Mitochondria are sausage-shaped small cell organelle present in the cytoplasm of a cell. Many thousands of mitochondria are present in a single cell of our body, only the red blood cells are devoid of this cell organelle. Mitochondria have got their own circular DNA with 16,569 base pair nucleotides and this genome codes for 37 proteins or encodes 37 genes. In a cell same type of mitochondria are present, but sometimes in a single cell both mutated and normal mitochondria can be present and this condition is called as heteroplasmy.
In recent years researchers have found out around 150 types of mutations of the mitochondrial DNA, and some of these mutations cause mitochondrial diseases, which affect the organs such as liver, kidney, skeletal muscle, endocrine system and also brain. These mitochondrial diseases are caused by mutations (acquired or inherited) in mitochondrial DNA or by mutations in the nuclear DNA region that code for mitochondrial parts.
Mitochondrial Disease 'New Treatment':
Mitochondria cell organelle or the mitochondrial DNA is passed on to offspring by mother via egg. That is mitochondrial DNA are not carried by nuclear DNA. Since there are many thousand number of mitochondria are present in a single cell, this makes it difficult to cure mitochondrial diseases using genetic-based cures. But a new technique called as chromosome transplant can be used to treat mitochondrial disease.
In chromosome transplant technique scientists speculated that women with mitochondrial disease could produce healthy children, by transferring mother's nuclear DNA into a chromosome-free egg that had normal mitochondria. This technique was used in monkeys and this technique was helpful in producing healthy monkeys.
Scientists from Oregon Health and Science University in Beaverton successfully created twin rhesus monkeys called Mito and Tracker using this technique called as DNA transplant. After transplanting the DNA, egg was fertilized using in vitro fertilization techniques. First scientists extracted the nuclear DNA from a mother monkey, who is suffering from mitochondrial disease and then transferred this nuclear DNA into healthy enucleated egg. By doing this step mutated form of mitochondrial DNA were eliminated from the fertilized egg.
As a result of this healthy babies were born with no mutated mitochondrial DNA. Scientists found not even single mitochondria with mutated form of DNA in baby monkeys.
It's too early to predict the implications of these techniques on humans. Since this technique creates changes in the DNA of a offspring which are transferred from one generation to other.
As usual there is opposition to chromosome transplant technique from some parts of the society, voicing concerns that this technique could induce some unintended side effects in a child, that is created using DNA from the mother, father and the donor mitochondrial DNA.
This DNA transplant technique can be used to treat mitochondrial disease and also some other diseases which are caused by genetic mutations. Instead of having a unhealthy child, we can used this technique to produce healthy next generation.
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