A PLOS One study suggests microbial communities may contribute to snow pack and surface snow features in the High Antarctic Plateau. A team from Italy and Belgium used a combination of 16S ribosomal RNA sequencing and fluorescence in situ hybridization, as well as phylogenetic approaches to assess snow samples collected at the Antarctic Plateau Concordia Research Station. Though the researchers detected relatively few microbes overall, they found that each of the techniques used to test the snow microbiomes turned up consistent microbial community members, particularly representatives from marine microbe groups such as Bacteroidetes and Cyanobacteria and microbes from the Alphaproteobacteria class.
In PLOS Genetics, two University of Oxford researchers present a haplotype-based approach for approximating rare variant ages in human populations. Using this method, which considers haplotype sharing patterns, the duo estimated ages for rare variants found in just two samples from the 1,000 Genomes Project. Their results suggest that in European or Asian populations, haplotype blocks containing this type of rare variant are roughly 50 generations to 160 generations old, while variants of comparable rarity occur in haplotypes going back an estimated 170 generations to 320 generations in African populations. On the other hand, the study's authors argued that these rare variants are likely closer to 320 generations to 670 generations old when shared by populations living on different continents.
Members of the Meta-analysis of type 2 diabetes in African Americans, or MEDIA, consortium used data from almost a dozen-and-a-half genome-wide association studies to explore the genetic architecture of type 2 diabetes in the African-American population — work they describe in PLOS Genetics. Using directly genotyped or imputed data at some 2.6 million SNPs, the group performed a meta-analysis of 8,284 African-American individuals with type 2 diabetes and 15,543 without. It then took 21 loci forward for replication testing in more than 11,500 African-American cases or controls, as well as tens of thousands of cases and controls of European descent. The search uncovered both new and known risk loci for type 2 diabetes and provided additional details about the pathways and processes that can go awry in the condition.