Transcriptional patterns found in human induced pluripotent stem cell lines hinge on the genetic background of the human iPS cells, according to a PLOS Genetics study by researchers at the Wellcome Trust Sanger Institute. The team performed RNA sequencing on more than two dozen iPS cell lines generated from the same types of somatic tissues from several different donors. Results from these experiments indicated that inter-individual genetic differences had a more pronounced effect on transcriptional diversity detected in human iPS cells than did epigenetic factors. As such, the researchers argue that "future studies using [human iPS cells] as a model system should focus most effort on collection of large numbers of donors, rather than generating large numbers of lines from the same donor."
In PLOS Pathogens, researchers from the US and Korea search for genetic features associated with Staphylococcus aureus infection susceptibility. Starting with a mouse strain known for being vulnerable to S. aureus infections, the team used array-based gene expression profiling and quantitative trait loci analysis to narrow in on a S. aureus susceptibility-associated region on chromosome 11 that contained five genes with differential expression in infected animals. Expression patterns for the same genes were subsequently found to shift in blood samples from humans with bloodstream infections caused by S. aureus, while investigators' follow-up experiments indicated that at least two of those genes contribute to cytokine immune responses.
McGill University's Timothy Geary and colleagues from Canada and the US did a proteomic analysis of fluid secreted by parasitic Ascaris suum worms — work they describe in PLOS Neglected Tropical Diseases. Using a combination of SDS-PAGE and mass spectrometry approaches, the group profiled proteins in fluid dissected from 10 full-grown, female A. suum worms. By comparing these protein profiles with those found in excretory or secretory fluids from the same worms, the researchers determined that the worms' secreted and excreted fluids contain proteins not present in the fluids from other parts of their bodies such as the uterus. The analysis "expands our knowledge of the biology of protein secretion from nematodes," study's authors say, "and will inform new studies on the function of secreted proteins in the orchestration of host-parasite interactions."