In this week's Science, a group of Japanese scientists identify a gene that enables certain rice varieties to grow taller rapidly in response to rising floodwaters. Performing a genome-wide association study using a range of rice varieties, the researchers found that when deepwater rice varieties are submerged, they amplify a signaling relay in which the gene SD1 is transcriptionally activated and increases synthesis of gibberellins — compounds that promote internode elongation. An evolutionary analysis suggests that variants of the SD1 gene have played roles in human rice cultivation, and the authors suggest that investigating other genetic variations in wild rice gene pools may help breeders fine-tune modern rice varieties amid climate changes. GenomeWeb has more on this study, here.
Also in Science, a Harvard Medical School team describes using CRISPR genome editing to engineer cancer cells to carry drugs to the tumors from which they originated. They created two types of cancer cells to express ligands specific to primary and recurrent tumor sites — "off-the-shelf" therapy-resistant ones for primary tumor settings; and patient-derived therapy-sensitive ones that were CRISPR-engineered for the autologous setting of recurrent or metastatic disease — and loaded them with a therapeutic payload. While both cell types killed tumor cells and extended survival in mouse models of different cancer types, the CRISPR-modified one included a prodrug-converting suicide system to enable their safe elimination after treatment. The investigators see their approach as a potential method for killing residual tumor deposits after surgical removal of a main tumor mass.