H7N9 bird flu mutations could enable spread between humans
In a new PLOS Pathogens study, researchers analyzed genome mutations that could occur in the H7N9 strain of avian influenza, which occasionally infects individual people but does not spread between humans. They focused on a gene that codes for the H7 type of hemagglutanin, a flu surface protein that allows the virus to latch strongly onto bird cells for infection.
The authors identified several H7 mutations that, when introduced experimentally, resulted in hemagglutanin molecules that had switched from binding bird cells to binding human cells more strongly. They cautioned that such a switch to human specificity could potentially enable H7N9 to spread between humans and recommended monitoring the flu strain for these mutations in the real world, triggering rapid action to prevent a pandemic.
New Brazilian species of ancient carnivorous mammal-like reptile
The Aleodon genus of carnivorous mammal-like reptiles, which evolved in the Triassic period and coexisted with dinosaurs, had previously only been found in Africa. However, researchers analysed Brazilian skulls, jaw and tooth fossils previously identified as being from the related Chiniquodon genus, and claim in research published in PLOS ONE that many are in fact Aleodons, making them the first Aleodon specimens discovered outside of Africa.
They also identified one specimen as a new Aleodon species and named it A. cromptoni, after Dr. Alfred “Fuzz” Crompton, who first described Aleodons. While this analysis was limited by the partial nature of some of the specimens, the findings may strengthen the correlation between Late Triassic mammal-like reptiles in South America and in Africa.
Genetic variants linked to higher BMI may protect against Parkinson’s
In a PLOS Medicine study, researchers used a Mendelian randomization approach to examine whether genetic variants linked to higher body mass index (BMI) were also associated with risk of Parkinson’s disease.
They found that genetic variants expected to confer lifetime exposure to a BMI higher by 5 were associated with an 18 percent lower risk of Parkinson’s disease. However, they note that Parkinson’s patients with a higher BMI tend to die earlier and so may be underrepresented in their analysis. The authors caution that while higher BMI is potentially protective against Parkinson’s disease, it is thought to have significant negative health impacts as well.
Image Credit: Martinelli et al., 2017
de Vries RP, Peng W, Grant OC, Thompson AJ, Zhu X, Bouwman KM, et al. (2017) Three mutations switch H7N9 influenza to human-type receptor specificity. PLoS Pathog 13(6): e1006390. https://doi.org/10.1371/journal.ppat.1006390
Martinelli AG, Kammerer CF, Melo TP, Paes Neto VD, Ribeiro AM, Da-Rosa ÁAS, et al. (2017) The African cynodont Aleodon (Cynodontia, Probainognathia) in the Triassic of southern Brazil and its biostratigraphic significance. PLoS ONE 12(6): e0177948. https://doi.org/10.1371/journal.pone.0177948
Noyce AJ, Kia DA, Hemani G, Nicolas A, Price TR, De Pablo-Fernandez E, et al. (2017) Estimating the causal influence of body mass index on risk of Parkinson disease: A Mendelian randomisation study. PLoS Med 14(6): e1002314. https://doi.org/10.1371/journal.pmed.1002314