Long-term exposure to a synthetic estrogen at levels below those currently found in the environment may have a major impact on fish populations, according to a study accepted today for publication in the December issue of the peer-reviewed journal Environmental Health Perspectives (EHP). The study shows that ethynylestradiol, a potent form of estrogen used in oral contraceptives, can produce sexually compromised males.
Researchers exposed zebrafish to low concentrations of the hormone over three generations and measured the effects. After 210 days, or a full zebrafish lifetime of exposure to ethynylestradiol, second-generation fish showed reduced fertility. In addition, out of nearly 12,000 eggs spawned, none were viable. Upon examination, researchers found that none of the second-generation male fish had normal testes, and they did not produce expressible semen. However, the fish showed normal reproductive behavior patterns, including competing with healthy males.
This research suggests that the development of the testes is more sensitive to disruption by ethynylestradiol than is reproductive behavior. This could have significant population-level consequences, as infertile males have a significant ability to interfere with breeding dynamics. “Previous studies in fish have shown that endocrine disruptors can reduce sperm counts and induce female-specific proteins in males,” said Dr. Jim Burkhart, science editor for EHP. “But until now little evidence existed to show that environmentally relevant concentrations of endocrine disruptors could induce such changes and actually reduce fertility.”
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
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...
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30.03.2017 | Health and Medicine
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