Although biomedical researchers have been investigating the links between epigenetics and human health for some time, evolutionary biologists are just beginning to take up the subject. Richards, who helped to organize a special symposium on ecological epigenetics at a meeting of the Society for Integrative and Comparative Biology (SICB) in San Francisco this month, says that the field has the potential to revolutionize the study of evolutionary biology.
Cyclostomes, the living jawless vertebrates including hagfishes and lampreys, represent the most basal lineage of vertebrates. … the phenotypic traits of hagfishes, especially the lack of some vertebrate-defining features and the reported endodermal origin of the adenohypophysis, have been interpreted as hagfishes exhibiting a more ancestral state than those of all other vertebrates. … Here we describe the craniofacial development of a series of staged hagfish embryos,… We also propose a possibility that the pan-cyclostome pattern may reflect the ancestral programme for the craniofacial development of all living vertebrates.
Potential Obesogen Identified: Fungicide Triflumizole Is Associated with Increased Adipogenesis in Mice
Obesogens are chemicals that increase either the number of fat cells in an organism or the amount of fat stored in those cells. Obesogens may also act indirectly on obesity by modulating appetite, satiety, or metabolism. Now researchers have identified a common agricultural chemical that appears to qualify as an obesogen because it nudges gene expression and stem cell differentiation toward becoming a fat cell [EHP 120(12):1720–1726; Li et al.].
A new study suggests that different mixes of intestinal microbes may determine whether people will have heart attacks or strokes brought on by break-away plaque from the arteries. Compared with healthy people, heart disease patients who have had strokes or other complications of atherosclerosis carry fewer microbes that make anti-inflammatory compounds. These patients also have more bacteria that produce inflammation-triggering molecules, researchers report online December 4 in Nature Communications. Inflammation is thought to promote cardiovascular disease.
“Our findings suggest that exposure to helminthes may improve symptoms by restoring the balance to the microbial communities that are attached to the intestinal wall,” Loke said. …
They also found that the expression of genes for inflammation had been reduced.
Toxicology generally assumes increasing frequency and severity of effects with increasing dose of a toxin, but:
But what if the Paracelsian presumption is wrong? What if, for a large and potent class of compounds, lower doses pose higher risks? A growing number of academic researchers are making just such a claim for endocrine disrupters, a large group of synthetic chemicals able to interact with cellular hormone receptors. These compounds, which range from the common weed killer atrazine and the plasticizer bisphenol A (BPA) to the antibacterial agent triclosan (used in cleansers) and the vineyard fungicide vinclozolin, don’t play by the usual rules of toxicology. On the basis of conventional high-dose testing, regulators have set maximum acceptable levels for each of them that assume all doses below that level are safe. But academic researchers who have studied a wider range of doses, including very low ones found in the everyday environment, say that their experiments usually do not generate the tidy, familiar ‘ski-slope’ dose-response graphs of classic toxicology. Instead, most endocrine disrupters have ‘non-monotonic’ dose-response curves, meaning that their slopes change at least once from negative to positive, or vice versa, forming ‘U’ shapes, inverted ‘U’s or even stranger shapes that resemble undulating Chinese dragons.
The Secrets of Viruses & Bacteria, Evolution to Epidemic
Dr. Shannon Bennett of the California Academy of Sciences discusses the secrets of viruses and bacteria, their evolution and eventual epidemic.
You could almost say that Shannon Bennett’s career as a virologist found her after she became infected with parasites while on a volunteer stint in Liberia during her college years. She was fascinated by the experience to the point that she has been on a quest to understand the secrets, the life cycle and evolutionary history of viruses and bacteria ever since. Hear about her research as she discusses fascinating examples from her work such as how the dengue virus continues to evolve and plague humans since jumping over from non-human primates decades ago. Learn how this virus has adapted to humans and the mosquitoes that have in turn become so well adapted to us. With these questions, Dr. Bennett’s work broadens the Academy’s research scope to include a dedicated focus on viruses and bacteria. As you will discover, she is especially interested in the nature of genetic mutations that give viruses the potential to cause epidemics or switch to new hosts.
Play time 01:03:01
Last week, a group of scientists in France released a study linking genetically modified food with cancer. Journalists who wanted to see an advanced copy of the research had to sign a confidentially agreement that ensured they wouldn’t be able to get other scientists to weigh in on the study. Brooke speaks to science writer Carl Zimmer, who says the researchers were trying to manipulate journalists in order to skew the coverage in their favor.
At least eight scientific associations are banding together to oppose the Government Spending Accountability (GSA) Act—which aims to limit government funding of conferences and meetings—over concern that it could stifle scientific collaboration.
Attending scientific conferences does not equate to the “team building,” Las Vegas boondoggle trips by GSA staff. Nonetheless, this bill passed the House on Sept 11, and is expected to be voted on by the Senate sometime this fall.