A few years ago, scientists at the University of Idaho discovered birth control pills not only control the human population, but also can devastate rainbow trout populations. Now they may know why.
James Nagler, professor of biological sciences, recently discovered that 17á-ethynylestradiol – an active chemical in birth control pills – causes cells in rainbow trout to have an abnormal number of chromosomes. This condition, known as aneuploidy, is often found in cancer cells, causes Down’s syndrome in humans, and may be why many embryos fathered by exposed specimens die within three weeks.
The results, coauthored with Kim Brown and Joe Cloud from the University of Idaho, and Irvin Schultz of Battelle Pacific Northwest National Laboratory – Marine Science Laboratory were published in this week’s edition of the Proceedings of the National Academy of Sciences.
“The bottom line is that aneuploidy is abnormal and highly undesirable,” said Nagler. “I believe this compound is causing elevated levels of sperm aneuploidy, which in turn is greatly reducing the embryonic survival rate in the fish it affects.”
Nagler exposed male rainbow trout to the chemical and tested their sperm for abnormal chromosome levels. He then fertilized eggs from unexposed females with the affected semen and compared the resulting offspring’s survival rate with a control group that was not exposed to the synthetic estrogen.
The results showed that while offspring sired by healthy male and female fish enjoyed a three-week survival rate of more than 95 percent, only 40 to 60 percent of the young trout from the affected semen survived. Additionally, the abnormal chromosomal levels were passed on to some of the offspring.
The chemical 17á-ethynylestradiol is a synthetic estrogen commonly used in human birth control pills and is released into the environment through urination. The compound is difficult to remove in waste treatment plants, and very few plants are capable of removing the chemical before releasing the water back into the environment.
“The concentrations we tested are not found everywhere,” said Nagler. “But there are definitely many places in the world containing levels close to – if not exceeding – the concentration that we tested.”
There are other synthetic estrogens released into the environment every day besides 17á-ethynylestradiol. Similar chemicals are found everywhere from detergents to pesticides and cause many more problems than chromosome abnormalities. For example, the pesticide DDT – a weak estrogen – caused the egg shells of bald eagles to be thin and weak, contributing to their declining numbers during the mid-1900s.
Nagler’s research results raise many questions on the levels of synthetic estrogens in surface water across the country and how they might be affecting all animals using the water, including humans.
“Nobody can say that these compounds are the main cause of salmon decline because it’s a very complex issue and there are many, many factors involved,” said Nagler. “But it can’t help.”
Image is available at www.today.uidaho.edu/PhotoList.aspx
Ken Kingery | Newswise Science News
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
27.10.2016 | Materials Sciences
27.10.2016 | Physics and Astronomy
27.10.2016 | Life Sciences