In this week's Nature Plants, an international research team presents a high-quality reference genome of Cardamine hirsuta, a close relative of the widely used model plant Arabidopsis thaliana, which they used to gain new insights into the genetics of evolutionary change. The researchers combined comparative genome and transcriptome analyses with experimental approaches to investigate gene function and phenotypic diversification. They identified key roles for transcription factors and tandem gene duplications in the evolution of morphology such as leaf shape. The findings highlight the benefits of using comparative approaches in genetically tractable species, the researchers say.
And in Nature Microbiology, a group led by University of Colorado scientists reports the reconstruction of a nearly complete genome for a ubiquitous soil bacterium dubbed Candidatus Udaeobacter copiosus. In their study, the investigators focused on bacteria within the Verrucomicrobia phylum, which are pervasive, but underrepresented in isolate collections and genomic databases. They found a spartobacterial phylotype that was consistently one of the most abundant in the more than 1,000 soil samples tested. They noted that the Ca. U. copiosus genome is unusually small for a cosmopolitan soil bacterium with multiple putative auxotrophies characteristic, all of which suggests that it may be "undergoing streamlining selection to minimize cellular architecture, a phenomenon previously thought to be restricted to aquatic bacteria," the investigators say. Though soil bacteria typically require large, complex genomes, Ca. U. copiosus appears to be taking an alternate approach, sacrificing metabolic versatility for efficiency.
Finally, in Nature Biotechnology, a team of Chinese and US scientists describes a new CRISPR-based method for screening functional long, non-coding RNAs. The approach is based on a lentiviral paired-guide RNA CRISPR-Cas9 library, and the investigators used it to identify 51 lncRNAs that positively or negatively regulate human cancer cell growth. They say that their method can be used to investigate phenotypic changes of interest other than cell growth by incorporating a reporter system, and may more broadly applied to study other non-coding sequences such as microRNAs. GenomeWeb has more on this study, here.