Researchers at the National Institute of Environmental Health Sciences and the University of California at Davis report that one of the body's approximately 70,000 proteins, called fertilin-beta, is essential for bringing together sperm and egg for fertilization. The research team, led by Chunghee Cho of UC-Davis, presented findings that will be a milestone in understanding how a new life begins.
The researchers believe this finding can pave the way for a non-hormonal approach to family planning and the diagnosis and treatment of some types of infertility.
Twenty years of work by the UC-Davis investigators established that fertilin-beta plays an important role in fusion of the sperm to the egg in fertilization. In this latest study, a collaboration with NIEHS scientists, mice were produced with a knockout of the fertilin-beta gene. The investigators were not surprised that sperm from these mice were unable to fuse with eggs. However, they did not expect to find that the sperm could not travel up the oviduct or bind to the zona pellucida, the envelope surrounding the egg.
The study, which appears in the journal Science, Vol. 281, pp. 1857-1859, was authored by Chunghee Cho, Ph.D.; Paul Primakoff, Ph.D.; and Diana G. Myles, Ph.D., all of University of California, Davis; and Eugenia H. Goulding; Edward M. Eddy, Ph.D.; and Donna O'Dell Bunch, Ph.D., of the Laboratory of Reproductive and Developmental Toxicology, NIEHS; and Jean-Emmanuel Faure, Ph.D., Ecole Normale Superieure de Lyon, Lyon, France.
Dr. Cho, first author on the paper, said that "astronomers study the Big
Bang, the moment when the Universe began. In life, sperm-egg fusion is the Big
Bang and we now understand more about the few seconds before and few seconds
after this event" said Dr. Cho. "With all the current concerns about the
possible effects of endocrine disruptors on fertility and of hormone-based
contraceptives on the development of so
Contact: Tom Hawkins
NIH/National Institute of Environmental Health Sciences