"In our experiment, we used 'knockout' mice that lacked the gene responsible for an enzyme important in making docosahexaenoic acid (DHA). In the absence of DHA, male mice are basically infertile, producing few if any misshaped sperm that can't get where they need to go," said Manabu Nakamura, a U of I associate professor of food science and human nutrition.
"We looked at sperm count, shape, and motility and tested the breeding success rate, and the mice lacking DHA simply were not able to breed," said Manuel Roqueta-Rivera, a U of I doctoral student who also worked on the study.
In the DHA-deficient knockout mice, sperm counts were extremely low. The sperm that were produced were round instead of elongated and they were unable to move well, he said.
But, when DHA was introduced into the diet, fertility was completely restored. "It was very striking. When we fed the mice DHA, all these abnormalities were prevented," he said.
This is the first time that the importance of DHA to male fertility has been shown this directly, although some studies have suggested that male fertility patients with low sperm counts and less motile sperm tend to have low levels of this fatty acid.
The DHA study is part of the Nakamura team's efforts to understand the function of the omega-3 and -6 fatty acids. As part of that work, they have developed a mouse model to help them understand a particular fat's physiological role. By knocking out genes, they can create deficiencies of the fats they are interested in and learn about their functions.
"Knocking out the gene for the delta-6-desaturase enzyme has led to some surprising discoveries, including this one about the importance of DHA in sperm formation and mobility," he said.
Nakamura said our body must make DHA from dietary alpha-linolenic acids, the parent compound of the omega-3 fatty acid family. Vegetable oils, including soybean and canola oil, are good sources of alpha-linolenic acid.
Nakamura's team plans to continue focusing on this omega-3's effects on fertility. But he cautioned that there are still things they don't understand.
"We get hints from looking at sperm in the DHA-deficient animals about what type of pathology we may be looking at and why these polyunsaturated fatty acids are important. But we're still at the starting point in understanding the mechanisms that are involved, and we need to do more research at the cellular level," he said.
The study was published in the February issue of the Journal of Lipid Research. Co-authors with Roqueta-Rivera and Nakamura are Chad K. Stroud, Wanda M. Haschek, Sandeep J. Akare, Mariangela Segre, and Rex A. Hess, all of the U of I, and Richard S. Brush, Martin-Paul Agbaga, and Robert E. Anderson, all of the University of Oklahoma Health Sciences Center.
Funding was provided in part by a CONACyT Mexico fellowship award, grants from the National Institutes of Health, the Foundation Fighting Blindness, and Research to Prevent Blindness.
Phyllis Picklesimer | EurekAlert!
Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland
Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences