University of Florida researchers looked at genetic variation in lice in the context of louse ecotype and the infected human population in a PLOS One study. Investigators turned to genomic analyses to find 15 louse microsatellite markers that they subsequently used to genotype head and clothing lice from nearly 100 individuals in North America, Central America, Asia, and Europe. Lice genetic profiles differed between clothing and head louse ecotypes, researchers report, and between lice from one geographical site and the next. As such, those involved in the study say microsatellite markers in lice may be useful for understanding not only louse biology and infection patterns, but also human migration history. For more on this study, see our sister publication GenomeWeb Daily News.
Mice exposed to ionizing radiation such as X-rays or gamma-rays show a shift in their blood microRNA profiles, according to another study in PLOS One. Using a digital, hybridization-based assay, researchers from Ohio State University and elsewhere tested blood samples from mice exposed to individual doses of gamma radiation or multiple X-ray treatments. Compared to untreated or sham-treated control animals, blood samples from the radiation-exposed mice exhibited a boost or dip in the expression of many miRNAs. At least a few of these miRNA expression changes seemed to coincide with radiation dose or related damage, the team notes, suggesting human versions of some of the miRNAs might eventually prove useful for tracking an individual's radiation exposure and/or risk of related complications. GWDN has more on the study here.
In PLOS Genetics, an international research team genotyped more than 1,300 Lebanese individuals as part of its effort to more clearly define historical human migrations in a Near East area known as the Levant. When they compared SNP profiles in the Lebanese samples with those found in individuals from four dozen other populations around the world, the investigators detected genetic patterns that appear to reflect ancient and more recent historical events in the Levantine. For example, results from the analysis suggest that Levantine populations tended to be more genetically related to Europeans prior to Islamic expansion into the region. On the other hand, some populations in the area now cluster more closely with populations in the Middle East and Africa — a pattern that the study's authors attribute to admixture between individuals with shared cultural and religious affiliations.