New In Vitro Strategies to Improve Healthy Baby Delivery Rate

 

    Studies using new IVF techniques performed by expert scientists at Britain's Newcastle University and and Monash University of Australia resulted in eight healthy babies being born. This new strategy combines the DNA from the mother, father, and an additional donor to lessen the risk of inheriting rare mitochondrial diseases. 

    The procedure is called pronuclear transfer, where the nuclear DNA from the mother and father is transferred into a donor egg that acquires healthy mitochondria, yet lacks the nuclear DNA. This results in the child having over 99% of their genetic material derived from the original parents, while allowing just enough DNA from the donor to replace disease-causing mitochondria. 

Figure I: chart demonstrating pronuclear transfer

    The outcome was a success, where all 8 babies (four girls and four boys) demonstrate on track development while presenting low non-disease causing and even undetectable levels of mitochondrial mutations.

    The downsides to this research is that long-term monitoring is required before this is an everyday practice. Additionally, it is also an ethical debate being that this technique involves gene alterations to humans. However, it is important to note that this is an incredible opportunity for families affected by mitochondrial diseases to be able to have children without passing down that unforgiving variant and it is a major stepping stone for other hereditary diseases as well. 

Sources:

https://mitocanada.org/what-is-mitochondrial-replacement-therapy/

https://www.scrippsnews.com/health/healthy-babies-born-in-britain-after-scientists-used-dna-from-three-people-to-avoid-genetic-disease 

 https://www.nejm.org/doi/full/10.1056/NEJMoa2415539 

Rice embryos formed by two specific genes

Despite rice being one of the most produced crops for the world's population, it is not grown often in high yields because obtaining or reproducing seeds on your own is expensive. A new solution has come to light in two genes in rice egg cells that activate embryo development without any fertilization. This was discovered by researchers from University of California's Davis and Berkely campuses and the solution would create highly efficient and high yielding clonal strains of rice and potentially other crops.

The researchers had known that activating a gene called BBM1 in rice egg cells activates the ability of a fertilized egg to form an embryo, but alone this only worked around 30% of the time. What they now discovered is the second gene WOX9A which when simultaneously activated can boost success rates to about 90%. This new discovery can allow for an easy cloning method which can increase rice production rates and lower costs.

I am hopeful for this discovery because it is potentially an inexpensive method for mass production of one of the most popular crops in history. Rice is a staple of agriculture already but with this new discovery it is possible that the amount of food in the world will increase and allow for struggling populations to get easy access to food.

Links:

https://www.britannica.com/plant/rice

https://phys.org/news/2024-11-biologists-genes-trigger-embryo-formation.html

A Baby Was Born With DNA From 3 People

A technique where the mother's DNA is removed from her egg and then placed inside a donor egg from another woman is called maternal spindle transfer. The egg is then fertilized and evolves into an embryo and is then transferred for pregnancy. A woman who had many failed cycles of IVF was able to give birth to a healthy baby boy, with this technique. According to Dr. Jonathon Tilly, mitochondria plays a key role with the development of embryos and fertilization. An abundance of data gathered suggests that people who have an infertility/ poor egg and embryo condition have mitochondrial dysfunction or deficiency.

I think this is a very interesting topic, many times infertility is blamed on other things such as birth control (which have no proven side affects of this), but a mitochondrial dysfunction/ deficiency makes sense. I also think it is great that there have been successful cases with the spindle transfer technique. I hope this can help many women in the future who have trouble with infertility and seek to have children.



https://time.com/5569057/three-parent-baby-dna/

Related Article:
https://www.newsweek.com/assisted-reproduction-ivf-maternal-spindle-transfer-three-parent-babies-1302044

Semi-Identical Twins

An article in the NY Times discusses the discovery and occurrence of neither fraternal nor identical twins, but semi-identical twins; also referred to ask sesquizcgotic twins. The twins share 100% of their maternal DNA and overlap on portions of their paternal DNA. Therefore, the twins are approximately three-fourths identical. 

At 14 weeks, Dr. Nicholas Fisk, a maternal fetal medicine specialist at the Royal Brisbane and Women’s Hospital, inspected an ultrasound and observed one body and one girl, sharing a placenta. Normally, identical twins develop when a single egg is fertilized by a single sperm and splits into two. However, regarding the semi-identical twins, Dr. Fisk suspects that a single egg was fertilized by two sperm before dividing because when the initial sperm entered the egg, the membrane failed to lock down to stop any other sperm from entering. Although, even if another sperm got into an egg, typically, it would result in three sets of chromosomes and a fatal outcome but this time it did not. 

Therefore, Dr. Fisk and his colleagues conducted an analysis of every single chromosome in the boy and the girl. They found no negative abnormalities, the mother had two healthy babies. Each baby contained the normal number of chromosomes, however, there were some areas where their DNA was identical and others where it was different, hence the term "semi-identical" twins. The children were monitored through out their childhood. By age 4, they were meeting all of their developmental markers by the appropriate time. Dr. Fisk sought to determine whether this phenomenon was more common than previously thought. He reviewed genetic data from nearly 1,000 fraternal twins but did not find any semi-identical twins among them. 

The discovery of the concept of semi-identical twins bring about a new phenomenon regarding the way in which mammalian eggs can be fertilized. More research needs to be conducted in order to find out the exact process by which this occurrence is possible.  

First Semi-Identical Twins

According to Science Daily, boy and girl twins have been identified as only the second set of semi-identical or sesquizcgotic twins in the world. They are also the first to be identified by doctors during pregnancy. The mothers ultrasound at six weeks showed a single placenta and positioning of amniotic sacs that indicated that she was expecting identical twins. At 14 weeks these identical twins have showed to be female and male. As most people know, identical female and male twins are not possible. However, in this case, they are.

Doctors state that the mothers egg was fertilized by two of the fathers sperm before dividing. Doctor Gabbett states that in this case, the fertilized egg appears to have equally divided up the three sets of chromosomes into groups of cells which then split into two, creating twins. Some of the cells have the chromosomes from the first sperm, while the remaining cells contain chromosomes from the second sperm, which results in the twins to share only a portion, rather than 100% of the same paternal DNA.
This is the second case which has not taken place since 2007 in United States. Mostly fraternal twins are highly possible for boy and a girl. The doctors are still studying this case, and are hoping for the mother to have a successful pregnancy so this could be further documented. I believe that with this new fertilization, doctors are able to identify, the how and the why of this pregnancy and would be able to procreate this method, since artificial insemination is now highly popular.

Scientists Can Design ‘Better’ Babies. Should They?

July 25, 2018 marks 40 years since the birth of Louise Brown, the first baby brought into the world by the process of in vitro fertilization. Since then, advancements in genetics have raised moral and ethical concern. For instance, pre-implantation genetic diagnosis, P.G.D, allows future parents to have their embryos tested for the probability of passing down diseases to their offspring. Some say this practice is unethical and interferes with nature. The most recent development in genetics and P.G.D was brought to attention by Dr. Jefferey Steinberg, director of The Fertility Institutes in New York. Dr. Steinberg expanded on the idea of P.G.D by introducing the opportunity to pick the child's gender and increasing their odds of their baby having a specific eye color. Additionally, Mitochondrial transfer allows women who have high odds of having a child with a severe birth defect use their own DNA and have it implanted in another woman's egg to move through the process. This was given a term called "three-parent baby". Furthermore, a gene-editing technology known as Crispr, can snip away a gene mutation. This results in the child not carrying this mutation, ultimately altering the family germ line. Overall, people are worried that "designer" babies will start to exist. More specifically, the wealthy who can afford these procedures could possibly one day chose to have a genius child or an Olympic athlete.

Many fear that this interferes with nature and is unethical. I believe that this can help many people to have a child but do feel there should be a line drawn. I find it interesting that they can pick eye color and gender but I think science should not go too far and interfere with nature.

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C. elegans might be the solution to a longer lifespan for humans

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Everyone is always trying to figure out how they can increase their lifespan. There is research in telomerase and telomeres to help with aging, and people change their lifestyle if it  However, it actually might be possible to actually increase our lifespan with the help of current research with C. elegans. According to the article, proteins are very important in the fertilization process. Apparently, they clump together and become deformed, and these proteins are passed down through the next generations despite being damaged. However, it turns out that right before fertilization occurs, these proteins are somehow wiped away. This process is done by the gene daf-2, which was discovered in the C. elegans. Apparently, if this gene is switched off, then it actually prolongs the lifespan of the nematodes, and this also lead to the discovery that there is an entire network of genes that help repair cells that have a buildup of damaged proteins. Plus, it turns out that humans have very similar genes that do this process as well. Also, apparently sperm is responsible for sending out a signal for the female egg to actually get rid of the proteins. So if the gene that is similar to daf-2 in humans in turned off, and sperm send the signal for the eggs to get rid of the damaged proteins, this actually allows for the fetus to not have deformed proteins, and improves it's lifespan.

I think that this study is very interesting because it sheds light to the possibility of being able to actually increase our lifespans. The idea that sperm are responsible for causing for damaged proteins to be removed from a egg is also fascinating because I didn't realize that this happened during fertilization. If we can turn off the gene in humans that us responsible for repairing cells, then it could greatly increase our children's lifespan, as well as promote healthier generations of human beings.

Gene-editing in human embryos

First U.S. team to gene-edit human embryos revealed

 (in vitro fertilization)

2 years ago, Chinese researchers announced the first editing of a human embryo. Ever since the announcement, many have felt that it was inevitable that the U.S. would follow suit. Then, earlier this year, MIT announced that such experiments have happened. In doing this, the team encountered and eventually began to be able to avoid additional off-target editing, which was predominant in many previous trials. Each study on the matter brings the topic closer to clinical application,
Ealrier this year, a panel consisting of the U.S. National Academy of Sciences and the National Academy of Medicine in Washington, D.C. decided that a clinical trial would be ethically allowable. This decision represents a shift in attitude which currently prevents the spending of taxpayers funds on research that destroys a human embryo. Slowly, as more problems can be avoided and edits can be made with more certainty, the clinical use of such technology will increase.
While many continue to feel that tampering with genomes is a dangerous thing to do, the safety of such methods is increasing. The method for editing embryos to eliminate diseases is increasingly successful with the selection of healthy embryos for in vitro fertilization. Although it may not be allowed at the moment, it could prove to be helpful and justifiable if it presents the only option for a couple to have a healthy biological child.

Reference: Servik K. (July 27, 2017). First U.S. team to gene-edit human embryos revealed. Science.