Researchers in Barcelona, Spain, report in a PNAS paper published online in advance this week a partial sequence for the melon genome, which they predict contains 27,427 protein-coding genes. "We assembled 375 Mb of the double-haploid line DHL92, representing 83.3 percent of the estimated melon genome," the authors write.
University of Minnesota's Nathan Springer and his colleagues examine how domestication has reshaped the transcriptome of maize seedlings by profiling the expression of 18,242 genes for 38 diverse maize genotypes and 24 teosinte genotypes in this week's PNAS Early Edition. "We detected evidence for more than 600 genes having significantly different expression levels in maize compared with teosinte," the authors write. "Moreover, more than 1,100 genes showed significantly altered coexpression profiles, reflective of substantial rewiring of the transcriptome since domestication."
Elsewhere in the Early Edition, investigators at the University of Rochester in New York show that Sirtuin 6, or SIRT6, "rescues the decline of homologous recombination repair during replicative senescence." Further, the team shows that this effect is dependent on the mono-ADP ribosylation activity of PARP1. Overall, the Rochester team writes in PNAS this week, "in aging cells, the precise HR [homologous recombination] pathway becomes repressed giving way to a more error-prone NHEJ [non-homologous DNA end joining] pathway."