Editor's Note: Some of the articles described below are not yet available at the PNAS site, but they are scheduled to be posted some time this week.
In the early, online edition of the Proceedings of the National Academy of Sciences, Ohio State University's Carlo Croce and colleagues explore changes in small non-coding RNAs called transfer RNA-derived small RNAs (tsRNAs) in chronic lymphocytic leukemia and lung cancer. Following from prior mouse studies of two microRNAs that regulate a CLL-related oncogene, the team used northern blot analyses and other approaches to demonstrate that the suspected miRNAs stem from transfer RNA sequences, now dubbed ts-3676 and ts-4521. In dozens of CLL and lung cancer samples, the investigators' RT-PCR experiments uncovered a cancer-related dip in ts-3676 and ts-4521 levels — part of a broader shift in tsRNA levels they detected in subsequent array-based studies on additional candidate tsRNAs in CLL, lung cancer, and control samples.
Japanese researchers introduce a database designed to correct for batch effects and other biases in gene expression data for another study set to appear online in PNAS this week. The resource, dubbed Immuno-Navigators, contains gene expression and co-expression information that's been corrected for batch effects, while taking into account type-specific expression correlation patterns. The database currently contains expression data for two dozen mouse immune cell types, which the team used for proof-of-principle analyses that uncovered new and known regulatory T cell regulators.
A study by a Yale University-led team takes a look at the role that Madagascar lemurs play in seed dispersal and plant lineage survival in an effort to understand the potential consequences of lemur extinctions. Using a combination of molecular phylogeny, lemur feeding habits and dietary history, and more, the researchers came up with models for the impact existing and extinct lemur species have had on Madagascar's plants. Their results suggest the loss of large lemurs has led to lower-than-usual seed dispersal, with "potentially far-reaching consequences for Malagasy plants. The authors' analyses also highlighted existing, but endangered, lemur species that seem to have crucial roles in plant seed dispersal.