sp. nov., a novel yeast species associated with Bengal clock vines and soil in Okinawa, Japan.

Two strains, designated JCM 36746 and JCM 36749, were isolated from Bengal clock vine () and soil, respectively, in Okinawa, Japan. Analysis of the internal transcribed spacer (ITS) regions and D1/D2 domains of the large subunit rRNA gene sequences revealed identical sequences in both strains, indicating that they belong to the same species. Sequence analysis and physiological characterization identified these strains as representing a novel yeast species in the genus .

sp. nov., a novel yeast species isolated from flowers and insects in Japan.

Two strains were isolated from flowers and insects in Japan, namely NBRC 115686 and NBRC 115687, respectively. Based on sequence analysis of the D1/D2 domain of the 26S large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region and physiological characteristics, these strains were found to represent a novel yeast species of the genus . Considering pairwise sequence similarity, NBRC 115686 and NBRC 115687 differ from the type strain of the most closely related species, NRRL Y-17645, by 65-66 nucleotide substitutions with 12 gaps (11.

Purifying selection enduringly acts on the sequence evolution of highly expressed proteins in Escherichia coli.

The evolutionary speed of a protein sequence is constrained by its expression level, with highly expressed proteins evolving relatively slowly. This negative correlation between expression levels and evolutionary rates (known as the E-R anticorrelation) has already been widely observed in past macroevolution between species from bacteria to animals. However, it remains unclear whether this seemingly general law also governs recent evolution, including past and de novo, within a species.

The sixth transmembrane region of a pheromone G-protein coupled receptor, Map3, is implicated in discrimination of closely related pheromones in Schizosaccharomyces pombe.

Most sexually reproducing organisms have the ability to recognize individuals of the same species. In ascomycete fungi including yeasts, mating between cells of opposite mating type depends on the molecular recognition of two peptidyl mating pheromones by their corresponding G-protein coupled receptors (GPCRs). Although such pheromone/receptor systems are likely to function in both mate choice and prezygotic isolation, very few studies have focused on the stringency of pheromone receptors.

Laboratory evolution of Mycobacterium on agar plates for analysis of resistance acquisition and drug sensitivity profiles.

Drug-resistant tuberculosis (TB) is a growing public health problem. There is an urgent need for information regarding cross-resistance and collateral sensitivity relationships among drugs and the genetic determinants of anti-TB drug resistance for developing strategies to suppress the emergence of drug-resistant pathogens. To identify mutations that confer resistance to anti-TB drugs in Mycobacterium species, we performed the laboratory evolution of nonpathogenic Mycobacterium smegmatis, which is closely related to Mycobacterium tuberculosis, against ten anti-TB drugs.

Elevated Sporulation Efficiency in Fission Yeast Strains Isolated from .

The fission yeast , comprising var. and var. varieties, has unique characteristics such as striking hyphal growth not seen in other species; however, information on its diversity and evolution, in particular mating and sporulation, remains limited.

High-throughput laboratory evolution reveals evolutionary constraints in Escherichia coli.

Understanding the constraints that shape the evolution of antibiotic resistance is critical for predicting and controlling drug resistance. Despite its importance, however, a systematic investigation of evolutionary constraints is lacking. Here, we perform a high-throughput laboratory evolution of Escherichia coli under the addition of 95 antibacterial chemicals and quantified the transcriptome, resistance, and genomic profiles for the evolved strains.

Complete Genome Sequences of Three Star-Shaped Bacteria, Stella humosa, Stella vacuolata, and Stella Species ATCC 35155.

species are unique star-shaped alphaproteobacteria found in various environments. We report the complete genome sequences of three strains, ATCC 43930, ATCC 43931, and species ATCC 35155. These are the first complete genome sequences of members of the genus .

High-throughput identification of the sensitivities of an Escherichia coli ΔrecA mutant strain to various chemical compounds.

Antibiotic resistance is considered a global threat to public health. Adaptive resistance mutations and the acquisition of resistance genes by horizontal gene transfer are known to be facilitated by the RecA-dependent SOS response during antibiotic treatment, making RecA inhibitors promising agents for the prevention of antibiotic resistance. However, the impact of RecA inactivation on antibiotic sensitivities remains unclear.

Prediction of Cross-resistance and Collateral Sensitivity by Gene Expression profiles and Genomic Mutations.

In adaptive evolution, an increase in fitness to an environment is frequently accompanied by changes in fitness to other environmental conditions, called cross-resistance and sensitivity. Although the networks between fitness changes affect the course of evolution substantially, the mechanisms underlying such fitness changes are yet to be fully elucidated. Herein, we performed high-throughput laboratory evolution of Escherichia coli under various stress conditions using an automated culture system, and quantified how the acquisition of resistance to one stressor alters the resistance to other stressors.