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Hard Thoughts On Soft Inheritance
Eric Richards, Ph.D., WUSTL professor of biology in Arts & Sciences, holding an Arabidopsis plant in the greenhouse.
But there also is evidence, particularly in plants, that non-genetic factors modifying the DNA can also be inherited. The modifications of the genetic material take the form of small chemical additions to one of the DNA bases and the alternative packaging of the DNA. These so-called epigenetic modifications are known to be important for turning genes on and off during the course of an organism's life, but their importance in controlling inheritance has been debated. A number of biologists are skeptical of any form of soft inheritance, where the genetic material is not constant, believing that it is only genetic information - DNA -- that can be passed onto generations. Now Eric Richards, Ph.D., professor of biology at Washington University in St. Louis, writing in the recent issue of Nature Reviews Genetics, analyzes recent and past research in epigenetics and the history of evolution and proposes that epigenetics should be considered a form of soft inheritance, citing examples in both the plant and mammalian kingdoms......... Posted by: Jessica Permalink Source The oxygen balance
The ratio (relative amount) of these two types of oxygen in water changes with the climate. By determining how the ratio of heavy and light oxygen in marine sediments, ice cores, or fossils is different from a universally accepted standard, scientists can learn something about climate changes that have occurred in the past. The standard scientists use for comparison is based on the ratio of oxygen isotopes in ocean water at a depth of 200-500 meters. What climate factors influence the ratio of oxygen isotopes in ocean water? Evaporation and condensation are the two processes that most influence the ratio of heavy oxygen to light oxygen in the oceans. Water molecules are made up of two hydrogen atoms and one oxygen atom. Water molecules containing light oxygen evaporate slightly more readily than water molecules containing a heavy oxygen atom. At the same time, water vapor molecules containing the heavy variety of oxygen condense more readily......... Posted by: Sarah Permalink Source Mercury in Aquatic Ecosystems
Field-deployed USGS Mobile Atmospheric Mercury Laboratory at Four Corners Study Site, Colorado.
Mercury that is released into the atmosphere can be transported long distances and deposited in aquatic ecosystems, where it is methylated to methylmercury. Mercury is a neurotoxicant, to which the human fetus is very sensitive. Methylmercury is an organic form of mercury, the most toxic form, and the form that bioaccumulates in fish. Wildlife and humans are exposed primarily through consumption of contaminated fish. The factors that make some aquatic ecosystems susceptible to this bioaccumulation, however, are unknown, making protection of human health and the health of fish-eating wildlife a challenge. Research focuses on the processes of mercury methylation and accumulation in aquatic ecosystems, factors that determine ecosystem susceptibility, and investigation of whether reduced emissions will reduce mercury accumulation in susceptible ecosystems......... Posted by: Tyler Permalink Source Three-clawed Crab
The crab is believed to have a genetic mutation
Fisherman Jeff Brown caught the 20cm (7.8in) edible crab three miles off Portreath and realising its rarity, handed it into a Newquay aquarium. The crab, christened Claudette by the Blue Reef aquarium staff, will be quarantined for several days before going on show. Manager David Waines said additional fully formed pincers on crabs were "incredibly rare"......... Posted by: Ashley Permalink Source Brazil Publishes Biodiversity Generic Name List
The Brazilian government has been, and is, involved in a number of trademark disputes with companies that, for example, take a name of a fruit in Brazilian Portuguese and trademark it to get exclusive rights to commercialise it under that name in a certain country or region. This hinders Brazilian exports, especially when it happens in larger markets, Cristiano Franco Berbert of the Permanent Mission of Brazil in Geneva told Intellectual Property Watch. Berbert said the mission has sent the list to the World Intellectual Property Organization (WIPO) and the World Trade Organization (WTO) to help raise awareness of the issue. The government also is looking into the possibility of the list being circulated at a future meeting of the WIPO Standing Committee on the Law of Trademarks, Industrial Designs and Geographical Indications, he said. WIPO members adopted a Revised Trademark Law Treaty in March of this year (IPW, WIPO, 5 April 2006). In addition, Brazil is looking into the list possibly being presented at the WTO Council on the Trade-Related Aspects of Intellectual Property Rights (TRIPS) agreement, Berbert said......... Posted by: Jessica Permalink Source Searching For A Woodpecker
An artist's image of what an ivory-billed woodpecker looks like. Credit: George M. Sutton/Cornell Lab of Ornithology
But last month scientists from NASA and the University of Maryland, College Park, Md., launched a project to identify possible areas where the woodpecker might be living. Finding these habitat areas will guide future searches for the bird and help determine if it is really extinct or has survived an elusive existence. The question of whether the species still exists started when a kayaker reported spotting the woodpecker along Arkansas' Cache River in 2004. That sighting spawned an intensive search for the species by wildlife conservationists, bird watchers, field biologists and others. In June a research aircraft flew over delta regions of the lower Mississippi River to track possible areas of habitat suitable for the ivory-billed woodpecker, one of the largest and most regal members of the woodpecker family. The project is supported by the U.S. Fish and Wildlife Service and the U.S. Geological Survey. Scientists from NASA's Goddard Space Flight Center, Greenbelt, Md., and the University of Maryland used NASA's Laser Vegetation Imaging Sensor (LVIS) onboard the aircraft. The instrument uses lasers that send pulses of energy to the Earth's surface. Photons of light from the lasers bounce off leaves, branches and the ground and reflect back to the instrument. By analyzing these returned signals, scientists receive a direct measurement of the height of the forest's leaf covered tree tops, the ground level below and everything in between......... Posted by: Ashley Permalink Source Brownfields May Turn Green
Kurt Thelen, MSU professor of crop and soil sciences, is leading the investigation to examine the possibility that some oilseed crops like soybeans, sunflower and canola, and other crops such as corn and switchgrass, can be grown on abandoned industrial sites for use in ethanol or biodiesel fuel production. Another partner is NextEnergy, a nonprofit organization that supports energy technology development. The results of the work conducted here might sprout similar sites across the state and nation in areas that aren't desirable for commercial or residential uses. The results also will contribute crops for biofuel production and may help clean up contaminated soils. "Right now, brownfields don't grow anything," Thelen said. "This may seem like a drop in the bucket, but we're looking at the possibilities of taking land that isn't productive and using it to both learn and produce". The project now is a two-acre parcel that is part of a former industrial dump site in Oakland County's Rose Township. Thelen's group is looking to determine if crops grown on brownfield sites can produce adequate yields to make them viable for use in biofuel production. The crops also need to produce adequate quantities of seed oil......... Posted by: Ashley Permalink Source How Kidneys Retain Proteins
Image courtesy of acem.org.uk
In genetically modified mice, scientists at Washington University School of Medicine in St. Louis captured images of a defective version of a kidney structure leaking a substance from the blood into the urine. The images suggest that the structure, known as the glomerular basement membrane (GBM), normally plays a key role in keeping blood proteins out of the urine. The finding, reported in the recent issue of the Journal of Clinical Investigation, will help doctors understand nephrotic syndrome, a condition with symptoms that include blood proteins in the urine. The syndrome can be triggered by a variety of genetic and environmental factors and leads to kidney failure over a varying time period. "All the treatments we now use for nephrotic syndrome are either non-specific, meaning that we can't say for sure that they directly address the problem, or they are toxic," notes lead author George Jarad, M.D., a postdoctoral research scholar. "The first step to developing a specific treatment is to understand exactly what's happening. We have to know the details of the process before we can devise a remedy"......... Posted by: Ashley Permalink Source Bat in the House?
Fortunately, a single bat flying in a room can usually be dealt with quite easily. Put away that broom or tennis racket and close off the room containing the bat and open an outside window or door in that room. It's usually only a matter of a few minutes of circling before the bat locates the open window and leaves the house. Bats do not attack people or fly into people's hair. If a bat has landed, it can be assisted out of a house in several ways. For a bat on a curtain, place a jar, coffee can or small box over the bat, carefully working the animal into the container, and cover it. A bat on the floor can be covered with a towel. Another method is to put on leather gloves and simply pick up the bat and release it outdoors-don't use cotton gloves or handle a bat with bare hands. Whatever method is used, don't worry when the bat squeaks loudly as you handle it. Take the bat outdoors and release it......... Posted by: Ashley Permalink Source Pigeons provide clues
"We identified a regulator of genes that controls the growth of artery smooth muscle cells," said William Wagner, Ph.D., senior researcher. "Learning to modulate the uncontrolled growth of these cells could potentially solve the problem of vessels re-closing after angioplasty". The work is published in the recent issue of Experimental and Molecular Pathology. Angioplasty uses a balloon-like device to crush the material blocking an artery. But, within three to six months, even if a stent is placed in the artery to keep it open, the vessel becomes re-blocked in about 25 percent to 30 percent of patients. This process, known as restenosis, has been described as "over exuberant" tissue healing and involves the smooth muscle cells. It is not known why this happens in some people and not in others, but a number of researchers think that genes are to blame, Wagner said. The scientists sought to find the answer in two breeds of pigeons one that is genetically susceptible to heart attacks and heart vessel disease (white carneau) and one (show racer) that is resistant. A major difference between the two breeds is that smooth muscle cells from the heart vessels of white carneau pigeons are prone to uncontrolled growth......... Posted by: Ashley Permalink Source |
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