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DNA methylation is an important mechanism of epigenetic modification. Methylation changes during stress responses and developmental processes have been well studied; however, their role in plant adaptation to the day/night cycle is poorly understood. In this study, we detected global methylation patterns in leaves of the black poplar Populus nigra 'N46' at 8:00 and 24:00 by methylated DNA immunoprecipitation sequencing (MeDIP-seq). We found 10,027 and 10,242 genes to be methylated in the 8:00 and 24:00 samples, respectively. The methylated genes appeared to be involved in multiple biological processes, molecular functions, and cellular components, suggesting important roles for DNA methylation in poplar cells. Comparing the 8:00 and 24:00 samples, only 440 differentially methylated regions (DMRs) overlapped with genic regions, including 193 hyper- and 247 hypo-methylated DMRs, and may influence the expression of 137 downstream genes. Most hyper-methylated genes were associated with transferase activity, kinase activity, and phosphotransferase activity, whereas most hypo-methylated genes were associated with protein binding, ATP binding, and adenyl ribonucleotide binding, suggesting that different biological processes were activated during the day and night. Our results indicated that methylated genes were prevalent in the poplar genome, but that only a few of these participated in diurnal gene expression regulation.

BACKGROUND: Abciximab is a widely used adjunctive therapy for acute coronary syndrome (ACS). However, the effect of intracoronary (i.c.) administration of abciximab on cardiovascular events remains unclear when compared with intravenous (i.v.) therapy. METHODOLOGY AND PRINCIPAL FINDINGS: We systematically searched the Medline, Embase, and Cochrane Central Register of Controlled Trials databases and reference lists of articles and proceedings of major meetings for obtaining relevant literature. All eligible trials included ACS patients who received either i.c. administration of abciximab or i.v. therapy. The primary outcome was major cardiovascular events, and secondary outcomes included total mortality, reinfarction, and any possible adverse events. Of 660 identified studies, we included 9 trials reporting data on 3916 ACS patients. Overall, i.c. administration of abciximab resulted in 45% reduction in relative risk for major cardiovascular events (RR; 95% confidence interval [CI], 24-60%), 41% reduction in RR for reinfarction (95% CI, 7-63%), and 44% reduction in RR for congestive heart failure relative to i.v. therapy (95% CI, 8-66%); however, compared to i.v. therapy, i.c. administration of abciximab had no effect on total mortality (RR, 0.69; 95% CI, 0.45-1.07). No other significant differences were identified between the effect of i.c. abciximab administration and i.v. therapy. CONCLUSIONS/SIGNIFICANCE: I.c. administration of abciximab can reduce the risk of major cardiovascular events, reinfarction, and congestive heart failure when compared with i.v. therapy.

The microRNAs (miRNAs) miR482 and miR1448 are disease resistance-related miRNAs; the former is ubiquitously distributed in seed plants whereas the latter has only been reported in Populus trichocarpa. The precursor and mature sequences of poplar miR1448 are highly homologous to those of poplar miR482, and these two miRNAs are located in one transcript as a polycistron. Therefore, we hypothesized that the MIR1448 gene may have evolved from the MIR482 gene in poplar. However, the molecular evolution patterns of this process remain unclear. In this study, utilizing cloning and Blast analysis in NCBI ESTs and whole-genome shotgun contigs (WGS) dataset, we determined that the MIR482-MIR1448 polycistron is a family-specific clustered miRNA in Salicaceae. Moreover, phylogenetic analysis illustrated that MIR1448 is the product of a tandem duplication event from MIR482. Nucleotide substitution analysis revealed that both MIR482 and MIR1448 have more rapid evolution ratios than ribosomal DNA (rDNA) genes, and that compensatory mutations that occurred in the stem region of the secondary structure were the main mechanisms that drove the evolution of these MIRNA genes. Furthermore, by comparing the substitution patterns in the miRNA-target complexes of miR482 and miR1448, we inferred that co-evolution between miRNAs and their targets was the major force that drove the “duplicated MIR482” evolve to MIR1448. We propose a novel miRNA-target pairing pattern called the “frameshift targeted mechanism” to explain the gain of target genes by miR1448. The results also imply that the major role of miR482 was in resistance to disease or other stresses via NBS-LRR proteins, whereas the biological functions of miR1448 are more diverse.