Evolution of an intermediate C4 photosynthesis in the non-foliar tissues of the Poaceae

Photosynthesis Research - Carbon concentrating mechanisms (CCMs) in plants are abaptive features that have evolved to sustain plant growth in unfavorable environments, especially at low atmospheric...     

The nuclease activities of both the Smr domain and an additional LDLK motif are required for an efficient anti‐recombination function of Helicobacter pylori MutS2

Helicobacter pylori, a human pathogen, is a naturally and constitutively competent bacteria, displaying a high rate of intergenomic recombination. While recombination events are essential for evolution and adaptation of H. pylori to dynamic gastric niches and new hosts, such events should be regulated tightly to maintain genomic integrity. Here, we analyze the role of the nuclease activity of MutS2, a protein that limits recombination during transformation in H. pylori. In previously studied MutS2 proteins, the C‐terminal Smr domain was mapped as the region responsible for its nuclease activity. We report here that deletion of Smr domain does not completely abolish the nuclease activity of HpMutS2. Using bioinformatics analysis and mutagenesis, we identified an additional and novel nuclease motif (LDLK) at the N‐terminus of HpMutS2 unique to Helicobacter and related ε‐proteobacterial species. A single point mutation (D30A) in the LDLK motif and the deletion of Smr domain resulted in ～ 5–10‐fold loss of DNA cleavage ability of HpMutS2. Interestingly, the mutant forms of HpMutS2 wherein the LDLK motif was mutated or the Smr domain was deleted were unable to complement the hyper‐recombination phenotype of a mutS2^? strain, suggesting that both nuclease sites are indispensable for an efficient anti‐recombinase activity of HpMutS2.     

Production and characterization of a novel protease from Bacillus sp. RRM1 under solid state fermentation

A commercially important alkaline protease, produced by Bacillus sp. RRM1 isolated from the red seaweed Kappaphycus alvarezii (Doty) Doty ex Silva, was first recognized and characterized in the present study. Identification of the isolated bacterium was done using both biochemical characterization as well as 16S rRNA gene sequencing. The bacterial strain, Bacillus sp. RRM1, produced a high level of protease using easily available, inexpensive agricultural residues solid-state fermentation (SSF). Among them, wheat bran was found to be the best substrate. Influences of process parameters such as moistening agents, moisture level, temperature, inoculum concentration, and co-carbon and co-nitrogen sources on the fermentation were also evaluated. Under optimized conditions, maximum protease production (i.e., 2081 U/g) was obtained from wheat bran, which is about 2-fold greater than the initial conditions. The protease enzyme was stable over a temperature range of 30-60 degrees C and pH 6-12, with maximum activity at 50 degrees C and pH 9.0. Whereas the metal ions Na+, Ca2+, and K+ enhanced the activity of the enzyme, others such as Hg2+, Cu2+, Fe2+, Co2+, and Zn2+ had rendered negative effects. The activity of the enzyme was inhibited by EDTA and enhanced by Cu2+ ions, thus indicating the nature of the enzyme as a metalloprotease. The enzyme showed extreme stability and activity even in the presence of detergents, surfactants, and organic solvents. Moreover, the present findings opened new vistas in the utilization of wheat bran, a cheap, abundantly available, and effective waste as a substrate for SSF.     

Are C-Reactive Protein Associated Genetic Variants Associated with Serum Levels and Retinal Markers of Microvascular Pathology in Asian Populations from Singapore?

Introduction

C-reactive protein (CRP) levels are associated with cardiovascular disease and systemic inflammation. We assessed whether CRP-associated loci were associated with serum CRP and retinal markers of microvascular disease, in Asian populations.

Methods

Genome-wide association analysis (GWAS) for serum CRP was performed in East-Asian Chinese (N = 2,434) and Malays (N = 2,542) and South-Asian Indians (N = 2,538) from Singapore. Leveraging on GWAS data, we assessed, in silico, association levels among the Singaporean datasets for 22 recently identified CRP-associated loci. At loci where directional inconsistencies were observed, quantification of inter-ethnic linkage disequilibrium (LD) difference was determined. Next, we assessed association for a variant at CRP and retinal vessel traits [central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE)] in a total of 24,132 subjects of East-Asian, South-Asian and European ancestry.

Results

Serum CRP was associated with SNPs in/near APOE, CRP, HNF1A and LEPR (p-values ≤4.7×10⁻⁸) after meta-analysis of Singaporean populations. Using a candidate-SNP approach, we further replicated SNPs at 4 additional loci that had been recently identified to be associated with serum CRP (IL6R, GCKR, IL6 and IL1F10) (p-values ≤0.009), in the Singaporean datasets. SNPs from these 8 loci explained 4.05% of variance in serum CRP. Two SNPs (rs2847281 and rs6901250) were detected to be significant (p-value ≤0.036) but with opposite effect directions in the Singaporean populations as compared to original European studies. At these loci we did not detect significant inter-population LD differences. We further did not observe a significant association between CRP variant and CRVE or CRAE levels after meta-analysis of all Singaporean and European datasets (p-value >0.058).

Conclusions

Common variants associated with serum CRP, first detected in primarily European studies, are also associated with CRP levels in East-Asian and South-Asian populations. We did not find a causal link between CRP and retinal measures of microvascular disease.     

Increased degradation of dermal collagen in diabetic rats.

The effect of alloxan induced diabetes on the dermal collagen content of albino rats was studied in relation to few lysosomal enzymes. Diabetes decreased the dermal collagen content. The specific activities of the lysosomal enzymes studied in the diabetic rat skin were elevated. It has been established that lysosomal enzymes degrade the connective tissue components. Thus, it may be suggested that the increase in the lysosomal enzymes studied should have facilitated the decrease in dermal collagen content of diabetic rats by increasing the degradation of dermal collagen.     

Characterization of a Novel Cr6+ Reducing Pseudomonas sp. with Plant Growth–Promoting Potential

The isolate RNP4 obtained from a long-term tannery waste contaminated soil was characterized and presumptively identified as Pseudomonas sp. The strain RNP4 tolerated concentrations up to 450 mg Cr⁶⁺/L on a Luria-Bartani (LB) agar medium and reduced a substantial amount of Cr⁶⁺ to Cr³⁺ in the LB liquid medium. The ability of performing multifarious activities in tandem suggested the uniqueness of isolate RNP4. The strain produced a substantial amount of indole acetic acid (IAA) in tryptophan-supplemented medium. The strain also exhibited the production of siderophore and solubilization of phosphorus in mineral salt medium and SRS1 medium, respectively. Concurrent production of IAA and siderophore and the solubilization of phosphorus revealed its plant growth promotion potential. Furthermore, the strain was able to promote the growth of black gram, Indian mustard, and pearl millet in the presence of Cr⁶⁺. Thus, the innate capability of this novel isolate for parallel bioremediation and plant growth promotion has significance in the management of environmental and agricultural problems.     

Synchronization analysis of the uterine magnetic activity during contractions

Background  

Our objective was to quantify and compare the extent of synchronization of the spatial-temporal myometrial activity over the human uterus before and during a contraction using transabdominal magnetomyographic (MMG) recordings. Synchronization can be an important indicator for the quantification of uterine contractions.