Things That Hold My Interest

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.].

In the spirit of Dante Alighieri’s Inferno, this paper takes a humorous look at the fate that awaits scientists who sin against best practice.

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.