In a paper published online in advance in Nature this week, a team led by researchers at Oregon Health and Science University describes "ploidy conveyor" as a source of genetic variation in hepatocytes. It shows that in mouse polyploidy hepatocytes, multipolar mitotic spindles frequently form — which "can result in one-step ploidy reversal to generate offspring with halved chromosome content," the team writes. The researchers suggest that hepatocyte polyploidization, ploidy reversal, and aneuploidy contribute to the dynamic model they've dubbed the ploidy conveyer.
In Nature Genetics this week, researchers report that "a locus on 19p13 modifies risk of breast cancer in BRCA1 mutation carriers and is associated with hormone receptor-negative breast cancer in the general population." In a genome-wide association study of 1,193 individuals with BRCA1 mutations who were diagnosed with breast cancer before the age of 40, and 1,190 BRCA1 carriers who are more than 35 years old who have not been diagnosed with breast cancer, the team found five SNPs on 19p13 that are associated with disease risk. "The five SNPs were also associated with triple-negative breast cancer in a separate study of 2,301 triple-negative cases and 3,949 controls," the authors report.
In another paper that examines variants at 19p13, a collaborative research team shows that two SNPs, rs8170 and rs2363956, are associated with serious epithelial ovarian cancer risk. In the group's "three-phase genome-wide association study of EOC survival in 8,951 ... cases with available survival time data and a parallel association analysis of EOC susceptibility," they also found that candidate gene expression at this locus "supported a role for the BRCA1-interacting gene C19orf62, also known as MERIT40, which contains rs8170, in EOC development," the authors write.
Two papers published in the Nature Reviews Genetics this week highlight "applications of next-generation sequencing" as part of a special series. Florida State University's David Gilbert considers genome-scale methods for evaluating replication timing in eukaryotic systems. The Broad Institute's Matthew Meyerson, Stacey Gabriel, and Gad Getz examine "advances in understanding cancer genomes through second-generation sequencing," and pontificate about the future prospects for whole-genome, -exome, and -transcriptome approaches for cancer research.