In PLoS Biology this week, a paper out of Jeff Lichtman’s lab has reconstructed the connectomes, or the complete connectional maps of neural circuits, of six interscutularis muscles from adult transgenic mice expressing fluorescent proteins in all motor axons. From these, his team concludes that muscle function in mammals “is implemented with a variety of wiring diagrams that share certain global features but differ substantially in anatomical form.”
Scientists have sequenced the 1.7-Mbp genome of Nautilia profundicola, an Epsilonproteobacterium found free-living at hydrothermal vents, and found some unique and some shared traits for vent-living. One in particular was a gene encoding for the “hallmark protein for hyperthermophilic growth,” reverse gyrase. They conclude that reverse gyrase is a common adaptation for mesophiles and moderate thermophiles living in environments with extreme fluctuations in temperature and not a unique feature of hyperthermophiles. Their work appears in PLoS Genetics last week.
In PLoS Computational Biology, scientists have performed a large-scale simulation study looking at how peptide conformation in water predicts native protein conformation. Using molecular dynamics simulations of almost 1,000 8-mer, 12-mer, and 16-mer peptide fragments from 13 proteins, they found that “a simple measure, the observed contact probability,” is more predictive of the native structure of a peptide in a protein than a combination of metrics.
Surveys conducted between 2002 and 2006 by WHO and the International Union Against Tuberculosis and Lung Disease have found that in 93 different geographical locations, the prevalence of multidrug resistant TB was up to 22 percent for newly diagnosed cases and up to 60 percent among previously treated cases. With those stats in mind, a group of researchers based at Harvard School of Public Health have established a comprehensive database listing mutations associated with drug resistance to TB and the frequency of the most common mutations associated with resistance to specific drugs. The database is freely available here, and their study is in PLoS Medicine.