Male fertility depends on sperm-cell architecture. A University of Illinois study reports that the specific omega-3 fatty acid (DHA) is necessary to construct the immature sperm cell into a properly-formed “pointy-headed super swimmer” with an extra long tail for effective motility.
“Normal sperm cells contain an arc-like structure called the acrosome that is critical in fertilization because it houses, organizes, and concentrates a variety of enzymes that sperm use to penetrate an egg,” explained Manabu Nakamura, a University of Illinois associate professor of biochemical and molecular nutrition.
The study shows for the first time that docosahexaenoic acid (DHA) is essential in fusing the building blocks of the acrosome together. “Without DHA, this vital structure doesn’t form and sperm cells don’t work,” said co-researchers conducting the study.
Men concerned about their fertility may want to increase their intake of foods containing DHA. Most often recommended are omega 3-rich fish, such as salmon, mackeral, trout or tuna, known as excellent sources of this omega-3 fatty acid.
The scientists became intrigued with DHA‘s role in creating healthy sperm when they experimented with laboratory subjects that lack a gene essential to its synthesis. “We looked at sperm count, shape, and motility, and tested the breeding success rate. The male mice that lacked DHA were basically infertile,” they said.
But when DHA was introduced into the subject’s diet, fertility was completely restored. “It was very striking. When we fed theDHA, all these abnormalities were prevented,” they added.
The scientists then used confocal laser scanning (3D) microscopy to look at thin slices of tissue in progressive stages of a sperm cell’s development. By labeling enzymes with fluorescence, they could track their location in a cell.
“We could see that the acrosome is constructed when small vesicles containing enzymes fuse together in an arc. But that fusion doesn’t happen without DHA,” they emphasized. In the absence of DHA, the vesicles are formed but they don’t come together to make the arch that is so important in sperm cell structure.
The role this omega-3 fatty acid plays in membrane fusion is particularly exciting, according to the researchers. Because DHA is abundant in specific tissues, including the brain and the retina as well as the testes, the scientists believe their research findings could also impact research relating to brain function and vision.
“It’s logical to hypothesize that DHA is involved in vesicle fusion elsewhere in the body, and because the brain contains so much of it, we wonder if deficiencies could play a role, for example, in the development of dementia. Any communication between neurons in the brain involves vesicle fusion,” they noted.
The Illinois research scientists will continue to study sperm; other laboratories are now studying DHA function in the brain and the retina.
Story Source: University of Illinois College of Agricultural, Consumer and Environmental Sciences.
Journal Reference: “Deficiency in the Omega-3 Fatty Acid Pathway Results in Failure of Acrosome Biogenesis in Mice” Biology of Reproduction, 2011;
This article is for informational and educational purposes only; It is not intended to provide medical advice, diagnosis or treatment; Consult your doctor or healthcare professional.