In PLOS Genetics, researchers from the Icahn School of Medicine and elsewhere describe a founder mutation involved in a subset of autosomal recessive leukoencephalopathy cases, a condition marked by white matter abnormalities in the central nervous system that produce neurological symptoms. The team did exome sequencing on five leukoencephalopathy-affected individuals from three Ashkenazi Jewish families, all showing similar developmental delay, seizure, and other symptoms. The search led to a homozygous, missense mutation in the vacuole protein-sorting gene VPS11 that subsequently turned up in other children with leukoencephalopathy. The investigators note that the alteration appears to be more common in individuals of Ashkenazi Jewish ancestry, with an estimated allele frequency of one in 250, but it was reported only rarely in the ExAc database.
A Brazilian team looks at the transcripts and proteins present in the saliva of the kissing bug Rhodnius neglectus, an insect that can transmit the Chagas disease-causing protozoan Trypanozoma cruzi. As they report in PLOS Neglected Tropical Diseases, the researchers used RNA sequencing and mass spectrometry to profile transcripts and proteins in saliva samples from nymph and adult kissing bugs raised at a Brazilian insectarium. The analysis uncovered transcripts coinciding with thousands of protein-coding genes, including 636 genes believed to code for secreted proteins found in insect saliva. Based on their findings, the study's authors argue that "[s]aliva contents have evolved to adapt to blood-feeding habit, ensuring the maintenance of blood flow, the success of the [blood] meal, and transmission of diseases."
French researchers reporting in PLOS One explore genetic diversity, relationships, and epidemiological patterns for Mycobacterium tuberculosis complex strains isolated from individuals diagnosed with tuberculosis in the Rhône Alpes region of France between 2000 and 2010. Using sequence typing strategies, phylogenetic analyses, and other approaches, the team assessed M. tuberculosis isolates from 2,257 TB-infected individuals, uncovering clusters of strains that largely coincided with evolutionarily recent Euro-American lineages. "We believe that the results obtained under this large population-based study represent an important initiative for the supervision, control, and eradication of TB in low-incidence western countries," the authors note.