Gene in Human Egg Essential for Fertility

A gene in the human egg that appears to be essential for fertility has been discovered by fertility researchers. The finding was reported in the April 2002 issue of Human Reproduction.

The gene may also play a role in premature ovarian failure, a condition in which the ovaries stop functioning for years or decades before natural menopause. Thus the gene may be associated with unexplained infertility in women. The discovery builds on prior research conducted in mice, where researchers found a gene in female mice that they named "Mater,” short for "maternal effect” gene.

The Mater gene produces a protein essential to the development of a fertilized egg. In the current study, a gene was identified in women that appears to be the human counterpart.

While investigating premature ovarian failure, the researchers found that in some cases, the ovaries of healthy women appeared to be attacked and destroyed by their immune systems. Mice with a similar disorder also experience such an attack. The target of the attack is a protein produced by the mouse Mater gene. To investigate this protein's function, the researchers developed a strain of mice that lacked both copies of the gene and found that all the females were infertile. They also found that the DNA of human and mouse Mater genes are 67% identical. The proteins produced by mouse and human Mater genes are 53% identical. Thus, the Mater mutation or its protein deficiency may cause infertility in some women.

”If the human gene is found to serve the same function as the mouse gene, it may result in a new approach to the study and treatment of fertility,” said Lawrence Nelson, M.D., senior author of the study and a member of the developmental endocrinology branch of the US National Institute of Child Health and Human Development (NICHD), which conducted the study.

One avenue of research suggested by the study is to examine women who have a history of successful fertilization but whose embryos fail to develop, to see if they have mutations on the Mater gene. If they do, researchers may one day be able to induce pregnancy by injecting Mater protein into the egg cells of such women before conception.





Related Links:
National Institute of Child Health and Human Development