In this week's PNAS Early Edition, researchers at the Cold Spring Harbor Laboratory in New York and their collaborators present evidence to suggest that "large cancer-associated deletions can produce phenotypes distinct from those arising through loss of a single TSG [tumor-suppressor gene], and as such should be considered and studied as distinct mutational events." The team tested its hypothesis — that large chromosomal deletions "can arise from selective pressure to attenuate the activity of multiple genes" — in a murine model of hepatocellular carcinoma using in vivo RNAi. "By targeting the mouse orthologs of genes frequently deleted on human 8p22 and adjacent regions ... we provide evidence suggesting that multiple genes on chromosome 8p can cooperatively inhibit tumorigenesis in mice, and that their cosuppression can synergistically promote tumor growth," the authors write.
Researchers at Canada's University of Western Ontario present a monomeric nuclease domain derived from GIY-YIG homing endonucleases that they say is suitable for genome-editing applications.
Elsewhere in the Early Edition, an international team led by the University of Queensland Diamantina Institute's Peter Visscher collate SNP data along with economic and political preferences and educational attainment information from participants who were genotyped as part of a genome-wide association study, in an effort to evaluate "the genetic architecture of economic and political preferences." Overall, Visscher et al. say that their analysis suggests that "these traits have a polygenic architecture, with the heritable variation explained by many genes with small effects," and add that their results "convey a cautionary message for whether, how, and how soon molecular genetic data can contribute to, and potentially transform, research in social science."
Finally, a team led by researchers at Erasmus Medical Center in the Netherlands this week shows that a SNP located in the DOT1L gene is strongly associated with a 12 percent reduced risk for hip osteoarthritis, reporting on findings from its recent GWAS on hip- joint-space width — used as a proxy for cartilage thickness — involving 6,523 participants. In its in vitro analyses of the DOT1L protein in mouse limbs, the team found that silencing of Dot1l inhibits chondrogenesis, and that "Dot1l knockdown reduces proteoglycan and collagen content, and mineralization during chondrogenesis," as the authors write in PNAS this week.