In a paper published online in advance in Nature this week, researchers at the Genome Institute of Singapore and their colleagues show that the transcription factor PRDM14 regulates the expression of POU5FI, a pluripotency gene, in human embryonic stem cells. In their subsequent genome-wide investigations, the team also found that "PRDM14 co-localized extensively with other key transcription factors such as OCT4, NANOG and SOX2," and in a gain-of-function assay they discovered that PRDM14 "is able to enhance the efficiency of reprogramming of human fibroblasts in conjunction with" KLF4, OCT4, and SOX2. The team says their data suggest PRDM14 is critical for hESC identity maintenance and the "reacquisition of pluripotency in human somatic cells," they write.
Researchers in France this week describe "maternal mRNA de-adenylation and decay by the piRNA pathway in the early Drosophila embryo." The team identified maternal mRNA decay and translation repression as functions of the piRNA pathway. Then, "using mRNA encoding the embryonic posterior morphogen Nanos as a paradigm to study maternal mRNA decay, we found that CCR4-mediated deadenylation of nos depends on components of the piRNA pathway including piRNAs complementary to a specific region in the nos 3' untranslated region," the authors write, adding that a complex of Smaug, CCR4, nos mRNA, and piRNAs target the nos 3' UTR. Additionally, the team writes, "because the piRNAs involved in this regulation are produced from transposable elements," their findings establish a "direct developmental function for transposable elements in the regulation of gene expression."
In another Nature advance online publication, investigators at the Stowers Institute for Medical Research in Kansas City, Mo., and the University of Kansas Medical Center report their use of quantitative proteomics and phenotypic profiling to find that "aneuploidy confers diverse phenotypes" in budding yeast. Specifically, the team created "38 stable and fully isogenic aneuploid yeast strains with distinct karyotypes," which they cultured in "quantitative growth assays under various conditions or in the presence of a panel of chemotherapeutic or antifungal drugs," they write. Overall, the Stowers Institute-led team found that, under some conditions, "aneuploid strains grew significantly better" better than control ones, which may indicate that "aneuploidy directly affects gene expression at both the transcriptome and proteome levels and can … bring about fitness gains under diverse conditions," the authors conclude.
An international research team shows in Nature this week that PRMT5 "links the circadian clock to the regulation of alternative splicing" in plants. In Arabidopsis, mutations in PRMT5 alter several circadian rhythms. "This phenotype is caused, at least in part, by a strong alteration in alternative splicing of the core-clock gene PRR9," the authors write. Furthermore, the Drosophila PRMT5 homologue is also associated with alterations in splicing events in several core-clock genes, the team shows.