The viability of a developing human embryo appears to be related to the clustering and subsequent symmetrical distribution of tiny DNA structures in the eggs fluid surrounding its nucleus prior to the first cell division, according to a new Colorado study.
University of Colorado at Boulder biology Professor Jonathan Van Blerkom said the study showed the roughly 140,000 tiny DNA structures, or mitochondria, in each egg are controlled by arrays of tube-like structures. The microtubules are created and the mitochonria migrate along them in the first few hours after fertilization.
A paper on the subject by Van Blerkom, CU-Boulder researcher, with Colorado Reproductive Endocrinology researcher Patrick Davis and Colorado Reproductive Endocrinology infertility specialist Dr. Sam Alexander, appeared in the December issue of the prestigious monthly journal Human Reproduction.
"I believe the take-home message is that these findings may help us determine the embryo quality at an earlier stage," said Dr. Alexander. "We feel that using methods to judge embryo quality in the first three days of culture is a much more sensible and intelligent approach than the five-day, survival of the fittest, embryo approach."
"Being able to determine the association between mitochondrial organization and egg competence non-invasively at an earlier stage would be a large step in predicting the eventual success or failure of the developing embryo," said Van Blerkom.
If the microtubule arrays in the egg cell do not mirror each other at the initial cell division, half of the dividing cells, or blastomeres, may carry too few mitochondria. Mitochondria are passed on maternally to offspring and are responsible for certain inherited traits and energy production, Van Blerkom said.
The research emphasis at the CRE clinic at Rose Medical Center has recently focused on genetics and blood flow into the follicles. "The follicles have provided us with more information the pas
Contact: Jonathan Van Blerkom
University of Colorado at Boulder