In Nature this week, an international research team led by investigators at the Washington University School of Medicine report its assembly of a draft orangutan genome, which it mapped using short-read sequence data from five Sumatran and five Bornean orangutans. The orangutan genome, the authors write, "has proceeded much more slowly than other great apes, evidenced by fewer rearrangements, less segmental duplication, a lower rate of gene family turnover and surprisingly quiescent Alu repeats." In addition, the WashU-led team also estimates that the Bornean/Sumatran speciation occurred 400,000 years ago. Our sister publication GenomeWeb Daily News has more here.
In another paper published online in advance in Nature this week, a UK research team headed up by investigators at the University of Bath describes "distinct physiological and behavioral functions for parental alleles of imprinted Grb10," a gene that encodes an intracellular adaptor protein that can affect downstream signaling molecules. The authors show that, in mice, Grb10 "is expressed from the paternal allele from fetal life into adulthood." Further, the team found that "ablation of this expression engenders increased social dominance," which makes Grb10 the "first example of an imprinted gene that regulates social behavior."
Researchers at China's National Institute of Biological Sciences and their collaborators discuss "how C/D RNAs assemble into RNPs." By determining the crystal structure of a catalytically active C/D RNA, the team found that fibrillarin not only "binds to an undistorted A-form structure of the guide-substrate duplex, it is also "positioned by non-specific and specific protein interactions," so that it facilitates site-specific ribose methylation.
FRA3B is a common fragile site in human lymphocytes and investigators at the Institut Curie in Paris and their colleagues show that its fragility "does not rely on fork slowing or stalling but on a paucity of initiation events" in certain cell types. "Initiation events are excluded from a FRA3B core extending approximately 700 kilobases" in lymphoblastoid cells, though not in fibroblasts, the authors write. The team suggests that "common fragile site contribution to chromosomal rearrangements in tumors should be reassessed after mapping fragile sites in the cell type from which each tumor originates," as a result of the specificity they've identified.