In Science this week, a team of US and European researchers publishes data showing that microRNAs can act to reduce the variability of protein expression in their target genes, suggesting that the small, non-coding RNAs can enable more precise cellular control of gene expression. Using a mathematical model and a synthetic gene approach, the researchers show that miRNAs, in conjunction with increased transcription, decrease protein expression noise for lowly expressed genes, but increase such noise for highly expressed genes. Notably, genes regulated by multiple miRNAs experienced more noise reduction. When looking at the full mouse genome, the researchers determined that miRNAs exert such influence on about 90 percent of the animal's genome. GenomeWeb has more on this here.
And in Science Translational Medicine, a group led by scientists from the Fred Hutchinson Cancer Research Center reported on the use of single-cell genotyping to uncover a more complex evolution of acute myeloid leukemia than previously thought. When applying the approach to human samples of acute myeloid leukemia and targeting two well-known cancer mutations, they found unexpected genetic diversity, identifying at least nine distinct clonal populations, each harboring unique mutational patterns. Some mutations seemed to arise independently and at different times, rather than sequentially. For more, check out this GenomeWeb article.
In Science Advances, a Massachusetts Institute of Technology-led team describes using the genome-editing technology CRISPR/Cas9 to change the genome of a yeast pathogen that causes dangerous infections. It has been difficult to genetically manipulate the pathogen, Candida albicans, limiting researchers' ability to study its essential genes and identify new drug targets. But by tweaking resistance genes, the scientists were able to make the yeast more sensitive to antibiotics. They also identified a gene that appeared to be essential to C. albicans.