Publications by authors named "Miki Umetani"
Most of the microbes in nature infrequently receive nutrients and are thus in slow- or non-growing states. How quickly they can resume their growth upon an influx of new resources is crucial to occupy environmental niches. Isogenic microbial populations are known to harbor only a fraction of cells with rapid growth resumption, yet little is known about the physiological characteristics of those cells and their emergence in the population.
View Article and Find Full Text PDFGene deletion is one of the standard approaches in genetics to investigate the roles and functions of target genes. However, the influence of gene deletion on cellular phenotypes is usually analyzed sometime after the gene deletion was introduced. Such lags from gene deletion to phenotype evaluation could select only the fittest fraction of gene-deleted cells and hinder the detection of potentially diverse phenotypic consequences.
View Article and Find Full Text PDFArticle Synopsis
- Genetic modifications in bacteria, like gene deletion, can greatly affect their survival, potentially leading to cell death, especially under stressors like antibiotics.
- A study investigated how individual bacterial cells adapt to the deletion of an antibiotic resistance gene when exposed to chloramphenicol; around 40% of the deleted cells were able to gradually restore their growth despite lacking the resistance gene.
- The adaptation process involved a recovery of the balance between key ribosomal proteins that was initially disrupted by the gene deletion, but the timing of genetic modification plays a critical role in whether bacteria can successfully adapt to such changes.
Cyanobacteria are unique organisms with remarkably stable circadian oscillations. These are controlled by a network architecture that comprises two regulatory factors: posttranslational oscillation (PTO) and a transcription/translation feedback loop (TTFL). The clock proteins KaiA, KaiB, and KaiC are essential for the circadian rhythm of the unicellular species Synechococcus elongatus PCC 7942.
View Article and Find Full Text PDFBackground: The cyanobacterial circadian program exerts genome-wide control of gene expression. KaiC undergoes rhythms of phosphorylation that are regulated by interactions with KaiA and KaiB. The phosphorylation status of KaiC is thought to mediate global transcription via output factors SasA, CikA, LabA, RpaA, and RpaB.
View Article and Find Full Text PDF