A new method for testing the genetic makeup of an egg may provide clues as to why some develop after fertilization and others do not, a finding with possible implications for in vitro fertilization, according to a paper published in the Journal of Biological Chemistry.
While using these findings for IVF appears feasible, it is "a long way off," said Adrian Reich GS, a co-author of the study.
Researchers from the Department for Molecular Biology, Cell Biology and Biochemistry studied RNA — genetic material that codes for proteins — in human eggs before fertilization. RNA begins to function in an egg immediately after fertilization, but before the cell starts to divide. The researchers believe RNA significantly impacts the egg's early development.
In the past, it has been difficult to obtain any kind of information about female eggs without destroying them in the process. This research shows that eggs' polar bodies — essentially biologically useless genetic copies of the egg — have similar RNA to their sister eggs. This innovation makes it possible to investigate the polar bodies for information about the actual eggs without harming them.
Theoretically, clinicians performing IVF will be able to test the polar body of an egg for indicators that suggest the egg will grow successfully. This research does not reveal those indicators, but it provides scientists with a method for investigating RNA's effects.
Reich authored the paper with Gary Wessel, professor of biology, and Peter Klatsky, a research fellow in the MCB department.
In the current IVF process, clinicians collect around 10 pre-eggs, called oocytes, fertilize them and wait two to three days to decide which to implant. On average, only three or four of them will successfully fertilize, and clinicians then have to choose one to implant without very much information. Many times, they choose eggs that look "the prettiest, even though many times the ugliest embryo grows into a happy and healthy baby," Reich said. This study may help change that paradigm.
