A new approach to embryo assessment described at this year’s Annual Meeting of ESHRE may be able to shed light on why so many apparently healthy embryos are not viable. The approach is based on the quantification of mitochondrial DNA found in the outermost layer of cells in a five-day old embryo. The combination of chromosome analysis and mitochondrial assessment may now represent the most accurate and predictive measure of embryo viability with great potential for improving IVF outcome.
Tag: DNA
Male Mitochondrial DNA Found to Self-Destruct After Arrival in Embryo
A team of researchers with members from Taiwan, the U.S., China and Japan has found that mitochondrial DNA from sperm that makes its way into an embryo begins to self-destruct before autophagosomes in the cytoplasm can reach it. In their paper published in the journal Science, the researchers describe their study involving the close monitoring of male mitochondrial DNA activity immediately after an embryo has been fertilized and as it is subsequently destroyed—they also offer some theories regarding why this occurs.
Why Do We Inherit Mitochondrial DNA Only From Our Mothers?
Our mitochondrial DNA accounts for a small portion of our total DNA. It contains just 37 of the 20,000 to 25,000 protein-coding genes in our body. But it is notably distinct from DNA in the nucleus. Unlike nuclear DNA, which comes from both parents, mitochondrial DNA comes only from the mother. Nobody fully understands why or how fathers’ mitochondrial DNA gets wiped from cells. An international team of scientists recently studied mitochondria in the sperm of a roundworm called C. elegans to find answers.
Improving Mitochondrial Replacement Therapy
In a study published today (June 8) in Nature, researchers at Newcastle University in the U.K. and their colleagues report having improved upon the pronuclear transfer technique, increasing the number of viable zygotes produced and reducing the number of defective mitochondria transferred along with nuclear DNA to the donor cell.
Control of Fertility: New Player Identified
Individual small RNAs are responsible for controlling the expression of gonadoliberin or GnRH (Gonadotropin-Releasing Hormone), a neurohormone that controls sexual maturation, the appearance of puberty, and fertility in adults, new research shows. The involvement of microRNAs, transcribed from DNA, occurs around birth, and marks a key step in postnatal development.
Future of Sperm Donor Anonymity Threatened by Growth of Genetic Testing
The rise of personal genetic testing and growth of international DNA databases could put an end to anonymous sperm and egg donation as donor-conceived individuals may unintentionally discover biological relatives, according to UCL researchers.
Ancient Virus Determines Babies’ Sex
Yale researchers believe an ancient viral DNA strand — incorporated into the mammalian genome as recently as 1.5 million years ago — plays a key role in turning off the X chromosome.
Three-Parent Children Are Already Here
This month, headlines have been filled with speculation about the social and ethical implications of “three-parent” children—that is, children born containing DNA from two mothers and one father through a set of in vitro fertilization procedures known as mitochondrial manipulation technologies.
Gene Editing: The Next Frontier in America’s Abortion Wars
Activists on both sides of the abortion debate now have a common enemy — the use of a powerful new gene editing technology to tinker with the human race. That may seem like an idea from a sci-fi flick, but it’s already here. The gene-editing technique is already used in research and has the potential to modify human DNA with unprecedented ease in the not-too-distant future. British regulators approved limited experiments in human embryos earlier this month.
Report: It’s Ethical to Test Embryos From DNA of 3 People
Creating babies from the DNA of three people — a man and two women — one day might prevent mothers from passing on devastating genetic diseases, and advisers to the government now say it’s ethical to test the procedure under certain conditions.