In this week's issue of Science, Johns Hopkins University scientists led by Erika Matunis examined the effect of negative feedback loops on maintaining different kinds of stem cells that reside in the same place, or niche. Using a combination, in part, of transcriptional profiling and confocal microscopy, the researchers found that in Drosophila testis the JAK-STAT signaling target and inhibitor Suppressor of cytokine signaling 36E (SOCS36E) "suppresses JAK-STAT signaling specifically in the somatic stem cells, preventing them from displacing neighboring germline stem cells," thus allowing both to coexist. "Our work exemplifies how one signaling pathway coordinately maintains two types of stem cells in a single niche," says the abstract.
Scientists led by senior author Lars Steinmetz of the European Molecular Biology Laboratory have found a genetic link to malaria infection resistance in the Anopheles gambiae mosquito. The team found that polymorphisms in a single gene, the antiparasitic thioester-containing protein 1, confer a "substantial part" of the ability of the mosquito to resist infection by Plasmodium parasites. They used a combination of techniques, including a genome-wide association study, targeted re-sequencing, and reciprocal allele-specific RNA interference, or rasRNAi. A story in GenomeWeb Daily News has the full scoop.
The University of Mainz's Barbara Bramanti is first author on a paper that looked into the link between ancient and modern farmers in Europe. Studying mitochondrial DNA sequences from late European hunter-gatherer skeletons, early farmers, and modern Europeans, her team found "large genetic differences between all three groups" and that 82 percent of the ancient hunter-gatherers "share mtDNA types that are relatively rare in central Europeans today," the abstract says. They conclude that it's likely that the first farmers were not the descendants of local hunter-gatherers but immigrated into central Europe at the start of the Neolithic.
Finally, a perspective by Gary Nabel at NIH's Vaccine Research Center examines the scientific method in light of systems biology, proposing an alternative model to hypothesis-driven research "based on decision, information, and game theory." He touches on the improvements that systems biology data has had on formulating hypotheses and advocates for it. "Hypothesis generation can create an organized body of knowledge from which insight can emerge," he says.