In PLOS Genetics, researchers from Brazil and the US present findings from a genome-wide association study of noise-induced hearing loss in a mouse model of the condition. The team tested four five-week-old female mice apiece from each of the hybrid mouse diversity panel strains for susceptibility to hearing loss in the weeks following exposure to two hours of loud noise. The GWAS pointed to a Nox3-containing peak on chromosome 17 that corresponded to a rise in hearing loss after exposure to sounds with frequencies above eight kilohertz. The study's authors subsequently validated the association with follow-up testing on mice missing one or both copies of the gene.
Papua New Guinean populations of the malaria-causing parasite Plasmodium vivax appear to have higher levels of diversity, but less pronounced population structure than those of another malaria parasite P. falciparum. As described in PLOS Neglected Tropical Diseases, an international team led by investigators in Australia genotyped P. falciparum and P. vivax isolates from populations in four parts of Papua New Guinea, focusing on 10 or 11 microsatellite markers. P. vivax populations at all four sites were diverse and surprising similar to one another, investigators report. On the other hand, the P. falciparum samples had lower diversity, but far more distinct population differentiation, clustering clearly by sampling site.
A PLOS One study by Canadian researchers highlights the challenges of tracking down microRNA signatures of disease-free survival in tumor samples. The team set out to find prognostic miRNAs for cervical carcinoma using flash-frozen, pre-treatment tumor biopsy and matched normal cervical samples for 79 women with the disease. The search led to nine miRNAs that seemed to coincide with survival outcomes. But attempts to verify the associations using formalin-fixed, paraffin-embedded samples from another 87 women with the disease fell short, despite the use of several miRNA profiling methods. "Our observations provide an important cautionary tale for future miRNA signature studies for cervical cancer," the study's authors write, "which can also be potentially applicable to miRNA profiling studies involving other types of human malignancies."