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To successfully survive and reproduce, all species constantly modify the structure and expression of their genomes to cope with changing environmental conditions including ultraviolet (UV) radiation. Thus, knowledge of species adaptation to environmental changes is a central theme of evolutionary studies which could have important implication for disease management and social-ecological sustainability in the future but is generally insufficient. Here, we investigated the evolution of UV adaptation in organisms by population genetic analysis of sequence structure, physiochemistry, transcription, and fitness variation in the radiation-sensitive 4 (RAD4) gene of the Irish potato famine pathogen Phytophthora infestans sampled from various altitudes. We found that RAD4 is a key gene determining the resistance of the pathogen to UV stress as indicated by strong phenotype-genotype-geography associations and upregulated transcription after UV exposure. We also found conserved evolution in the RAD4 gene. Only five nucleotide haplotypes corresponding to three protein isoforms generated by point mutations were detected in the 140 sequences analyzed and the mutations were constrained to the N-terminal domain of the protein. Physiochemical changes associated with non-synonymous mutations generate severe fitness penalty to mutants, which are purged out by natural selection, leading to the conserved evolution observed in the gene.

Climate change is considered a major threat to society and nature. UV irradiation is the most important environmental genotoxic agent. Thus, how elevated UV irradiation may influence human health and ecosystems has generated wide concern in the scientific community, as well as with policy makers and the public in general. In this study, we investigated patterns and mechanisms of UV adaptation in natural ecosystems by studying a gene-specific variation in the potato late blight pathogen, Phytophthora infestans. We compared the sequence characteristics of radiation sensitive 23 (RAD23), a gene involved in the nucleotide excision repair (NER) pathway and UV tolerance, in P. infestans isolates sampled from various altitudes. We found that lower genetic variation in the RAD23 gene was caused by natural selection. The hypothesis that UV irradiation drives this selection was supported by strong correlations between the genomic characteristics and altitudinal origin (historic UV irradiation) of the RAD23 sequences with UV tolerance of the P. infestans isolates. These results indicate that the RAD23 gene plays an important role in the adaptation of P. infestans to UV stress. We also found that different climatic factors could work synergistically to determine the evolutionary adaptation of species, making the influence of climate change on ecological functions and resilience more difficult to predict. Future attention should aim at understanding the collective impact generated by simultaneous change in several climate factors on species adaptation and ecological sustainability, using state of the art technologies such as experimental evolution, genome-wide scanning, and proteomics.

Genetic variation plays a fundamental role in pathogen's adaptation to environmental stresses. Pathogens with low genetic variation tend to survive and proliferate more poorly due to their lack of genotypic/phenotypic polymorphisms in responding to fluctuating environments. Evolutionary theory hypothesizes that the adaptive disadvantage of genes with low genomic variation can be compensated for structural diversity of proteins through post-translation modification (PTM) but this theory is rarely tested experimentally and its implication to sustainable disease management is hardly discussed. In this study, we analyzed nucleotide characteristics of eukaryotic translation elongation factor-1 alpha (eEF-l alpha) gene from 165 Phytophthora infestans isolates and the physical and chemical properties of its derived proteins. We found a low sequence variation of eEF-l alpha protein, possibly attributable to purifying selection and a lack of intra-genic recombination rather than reduced mutation. In the only two isoforms detected by the study, the major one accounted for >95% of the pathogen collection and displayed a significantly higher fitness than the minor one. High lysine representation enhances the opportunity of the eEF-1 alpha protein to be methylated and the absence of disulfide bonds is consistent with the structural prediction showing that many disordered regions are existed in the protein. Methylation, structural disordering, and possibly other PTMs ensure the ability of the protein to modify its functions during biological, cellular and biochemical processes, and compensate for its adaptive disadvantage caused by sequence conservation. Our results indicate that PTMs may function synergistically with nucleotide codes to regulate the adaptive landscape of eEF-1 alpha, possibly as well as other housekeeping genes, in P. infestans. Compensatory evolution between pre- and post-translational phase in eEF-1 alpha could enable pathogens quickly adapting to disease management strategies while efficiently maintaining critical roles of the protein playing in biological, cellular, and biochemical activities. Implications of these results to sustainable plant disease management are discussed.

To observe the effects of serum containing Mahuang (Herba Ephedra Sinica) or Wuweizi (Fructus Schisandrae Chinensis) on the migration of alveolar macrophages (AM) and interstitial macrophages (IM) from normal rats, and to analyze and compare the mechanisms leading to cell migration differences.Rats were randomly divided into three groups: Mahuang (Herba Ephedra Sinica), Wuweizi (Fructus Schisandrae Chinensis), and blank serum. After treatment with the herbs, serum was extracted from the rats. AM and IM were isolated from normal rats and cultured. The effects of Mahuang (Herba Ephedra Sinica) and Wuweizi (Fructus Schisandrae Chinensis) medicated serum on normal rat AM and IM chemotactic migration were determined by transwell assays. The CC chemokine receptor (CCR) 2, CCR5, voltage-gated Kvl. 3 K+ channel (Kv1. 3), and voltage-gated Kvl. 5 K+ channel (Kv1. 5) protein levels were analyzed by western blotting.The migration quantities of AM and IM in the Mahuang (Herba Ephedra Sinica) and Wuweizi (Fructus Schisandrae Chinensis) medicated serum groups were significantly higher than those in the blank serum group (P0.01). Compared with the Wuweizi (Fructus Schisandrae Chinensis) medicated serum group, the migration quantity of cultured rat AM in the Mahuang (Herba Ephedra Sinica) medicated serum group was significantly increased (P0.01). Meanwhile, compared with the Mahuang (Herba Ephedra Sinica) medicated serum group, the migration quantity of cultured rat IM in the Wuweizi (Fructus Schisandrae Chinensis) medicated serum group was significantly increased (P0.01). CCR2, CCR5, Kv1. 3, and Kv1. 5 proteins were expressed on the AM cell surface, and showed significantly higher expression in the Mahuang (Herba Ephedra Sinica) medicated serum group compared with the Wuweizi (Fructus Schisandrae Chinensis) medicated serum group. In contrast, CCR5, Kv1.3, and Kv1.5 proteins were expressed on the IM cell surface, and showed significantly higher expression in the Wuweizi (Fructus Schisandrae Chinensis) medicated serum group compared with the Mahuang (Herba Ephedra Sinica) medicated serum group.Mahuang (Herba Ephedra Sinica) and Wuweizi (Fructus Schisandrae Chinensis) can promote AM and IM migration ability, with Mahuang (Herba Ephedra Sinica) targeting AM more apparently and Wuweizi (Fructus Schisandrae Chinensis) targeting IM more apparently. The mechanism may be that, by stimulating cells, Mahuang (Herba Ephedra Sinica) and Wuweizi (Fructus Schisandrae Chinensis) promote expression of CCR2 and CCR5 receptors on the AM and IM cell surface, which pass signals to Kvl.3 and Kvl.5 ion channels, leading to changes in the cytoskeleton, and ultimately promoting chemotactic cell migration.

Additional file 4: Figure S3. Flow cytometry analysis of surface ICAM-1 and VCAM-1 expression. A. HUVECs were treated with normal-HDL, C-HDL( 50 μg/mL) and C-HDL( 100 μg/mL)then analyzed by flow cytometry for surface ICAM-1 and VCAM-1 expression. B. C-HDL induced increased proportion of ICAM-1 + VCAM-1 + endothelial significantly. n = 3 independent experiments; (**P

Recently, Tian et al. [Computers and Mathematics with Applications, 75(2018): 2710-2722] came up with the inner-outer iterative method to solve the linear equation Ax=b and studied the corresponding convergence of the method. In this paper, we improve the main results of the inner-outer method and get weaker convergence results. Moreover, the parameters can be adjusted suitably so that the convergence property of the method can be substantially improved.