IVF: What makes a good egg?

via hedgefertility.com

"In approximately 15 percent of cases where couples are unable to conceive, the underlying cause of infertility is not known. Researchers at University of California San Diego School of Medicine and in the Division of Biological Sciences at UC San Diego have identified a protein in mice that must be present in eggs for them to complete normal development. Without the protein, called ZFP36L2 or L2 for short, the eggs appear ordinary, but they cannot be fertilized by sperm. Female mice lacking L2 in their eggs ovulate and are otherwise healthy, but they produce no offspring.

Since humans also have the L2 protein, this finding, published February 5 in Developmental Cell, gives researchers a new place to look for answers to currently unexplained causes of female infertility.

"In my clinical practice, I work with couples struggling with infertility," said senior author Heidi Cook-Andersen, MD, PhD, assistant professor of reproductive medicine and biological sciences at UC San Diego and physician at the UC San Diego-affiliated Reproductive Partners Fertility Center-San Diego. "It's frustrating that for many of them, we have no idea why it's difficult for them to conceive. All of their tests come back normal, but there are many things important for fertility that we still haven't discovered. And we can't test what we don't know. That's why this study is so exciting to us. It's another clue."

L2 plays an important role in cells by activating mRNA decay, a system cells use to turn off gene expression when the proteins encoded by the mRNAs are no longer needed. Some of the team's collaborators had previously found that L2 is needed for normal blood cell development. These earlier studies also suggested a link to female fertility, but whether L2 played any role in the egg itself remained unclear..."

Learn more:

https://www.sciencedaily.com/releases/2018/02/180205161829.htm