A Pasteur Institute-led team used genome sequencing to characterize Chikungunya virus isolates involved in an outbreak of the arbovirus in the Caribbean islands of Guadeloupe and Martinique starting in late 2013. As they report in PLOS Neglected Tropical Diseases, the researchers attempted to sequence viruses from 100 individuals who had tested positive for Chukungunya virus by qRT-PCR, successfully generating deep sequence data for 20 of the samples and partial sequence for five more. Their analyses pointed to diversity in the Chikungunya virus population that arrived in the Caribbean, with some minor variants climbing to relatively high frequency during the outbreak. And through genetic engineering, the study's authors identified a new 3' untranslated region that appears to boost the virus' replication in insect cells.
In PLOS One, Australian researchers report on genetic diversity detected in dogs from the Bullmastiff breed. The team used a canine array to genotype 188 Bullmastiff dogs. When they brought this SNP data together with genealogical information from a database spanning more than three decades and containing information on nearly 16,400 Bullmastiff pedigrees, the study's authors got a look at founder population size for the breed and an estimated inbreeding coefficient, along with Bullmastiff genetic diversity and population structure. "While current levels of Bullmastiff heterozygosity, inbreeding, and homozygosity are not unusual," they write, "a relatively small effective population size indicates that a breeding strategy to reduce the inbreeding rate may be beneficial."
A team from Finland reporting in PLOS Genetics describes a recurrent mutation in the DNA damage response gene MCPH1 that appears increase breast cancer risk in individuals from the Finnish population. Through targeted sequencing on almost 800 DNA repair-related genes in 189 Finnish individuals with suspected hereditary breast cancer, the researchers tracked down a heterozygous MCPH1 mutation that subsequently turned up in 21 breast cancer-affected families, including some with additional brain tumors and/or sarcoma. "These findings collectively provide strong evidence for MCHP1 being a novel breast cancer susceptibility gene," the authors note, "which warrants further investigations in other populations."