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991.
Metabolic engineering strategies have enabled improvements in yield and titer for a variety of valuable small molecules produced naturally in microorganisms, as well as those produced via heterologous pathways. Typically, the approaches have been focused on up‐ and downregulation of genes to redistribute steady‐state pathway fluxes, but more recently a number of groups have developed strategies for dynamic regulation, which allows rebalancing of fluxes according to changing conditions in the cell or the fermentation medium. This review highlights some of the recently published work related to dynamic metabolic engineering strategies and explores how advances in high‐throughput screening and synthetic biology can support development of new dynamic systems. Dynamic gene expression profiles allow trade‐offs between growth and production to be better managed and can help avoid build‐up of undesired intermediates. The implementation is more complex relative to static control, but advances in screening techniques and DNA synthesis will continue to drive innovation in this field. 相似文献
992.
Jaime Vargas Montse Pérez Jorge Toro Marcela P. Astorga 《Genetics and molecular biology》2015,38(2):173-181
This study presents evidence, using sequences of ribosomal 16S and COI mtDNA, for the presence of two mitochondrial genomes in Perumytilus purpuratus. This may be considered evidence of doubly uniparental mtDNA inheritance. The presence of the two types of mitochondrial genomes differentiates females from males. The F genome was found in the somatic and gonadal tissues of females and in the somatic tissues of males; the M genome was found in the gonads and mantle of males only. For the mitochondrial 16S region, ten haplotypes were found for the F genome (nucleotide diversity 0.004), and 7 haplotypes for the M genome (nucleotide diversity 0.001), with a distance Dxy of 0.125 and divergence Kxy of 60.33%. For the COI gene 17 haplotypes were found for the F genome (nucleotide diversity 0.009), and 10 haplotypes for the M genome (nucleotide diversity 0.010), with a genetic distance Dxy of 0.184 and divergence Kxy of 99.97%. Our results report the presence of two well-differentiated, sex-specific types of mitochondrial genome (one present in the male gonad, the other in the female gonad), implying the presence of DUI in P. purpuratus. These results indicate that care must be taken in phylogenetic comparisons using mtDNA sequences of P. purpuratus without considering the sex of the individuals. 相似文献
993.
Mariele Porto Carneiro Le?o Patricia Vieira Tiago Fernando Dini Andreote Welington Luiz de Araújo Neiva Tinti de Oliveira 《Genetics and molecular biology》2015,38(1):86-92
The entomopathogenic fungi of the genus Metarhizium have several
subtilisin-like proteases that are involved in pathogenesis and these have been used
to investigate genes that are differentially expressed in response to different
growth conditions. The identification and characterization of these proteases can
provide insight into how the fungus is capable of infecting a wide variety of insects
and adapt to different substrates. In addition, the pr1A gene has
been used for the genetic improvement of strains used in pest control. In this study
we used quantitative RT-PCR to assess the relative expression levels of the
pr1A gene in M. anisopliae and M.
acridum during growth in different culture conditions and during
infection of the sugar cane borer, Diatraea saccharalis Fabricius.
We also carried out a pathogenicity test to assess the virulence of both species
against D. saccharalis and correlated the results with the pattern
of pr1A gene expression. This analysis revealed that, in both
species, the pr1A gene was differentially expressed under the growth
conditions studied and during the pathogenic process. M. anisopliae
showed higher expression of pr1A in all conditions examined, when
compared to M. acridum. Furthermore, M. anisopliae
showed a greater potential to control D. saccharalis. Taken
together, our results suggest that these species have developed different strategies
to adapt to different growing conditions. 相似文献
994.
Two guard cell mitogen‐activated protein kinases,MPK9 and MPK12, function in methyl jasmonate‐induced stomatal closure in Arabidopsis thaliana 下载免费PDF全文
W. Ye M. A. Hossain M. Uraji Y. Nakamura I. C. Mori J. M. Kwak Y. Murata 《Plant biology (Stuttgart, Germany)》2015,17(5):946-952
Methyl jasmonate (MeJA) and abscisic acid (ABA) signalling cascades share several signalling components in guard cells. We previously showed that two guard cell‐preferential mitogen‐activated protein kinases (MAPKs), MPK9 and MPK12, positively regulate ABA signalling in Arabidopsis thaliana. In this study, we examined whether these two MAP kinases function in MeJA signalling using genetic mutants for MPK9 and MPK12 combined with a pharmacological approach. MeJA induced stomatal closure in mpk9‐1 and mpk12‐1 single mutants as well as wild‐type plants, but not in mpk9‐1 mpk12‐1 double mutants. Consistently, the MAPKK inhibitor PD98059 inhibited the MeJA‐induced stomatal closure in wild‐type plants. MeJA elicited reactive oxygen species (ROS) production and cytosolic alkalisation in guard cells of the mpk9‐1, mpk12‐1 and mpk9‐1 mpk12‐1 mutants, as well in wild‐type plants. Furthermore, MeJA triggered elevation of cytosolic Ca2+ concentration ([Ca2+]cyt) in the mpk9‐1 mpk12‐1 double mutant as well as wild‐type plants. Activation of S‐type anion channels by MeJA was impaired in mpk9‐1 mpk12‐1. Together, these results indicate that MPK9 and MPK12 function upstream of S‐type anion channel activation and downstream of ROS production, cytosolic alkalisation and [Ca2+]cyt elevation in guard cell MeJA signalling, suggesting that MPK9 and MPK12 are key regulators mediating both ABA and MeJA signalling in guard cells. 相似文献
995.
Yongxia Yang Ying Liu Lingyun Zheng Qianqian Zhang Quliang Gu Linlin Wang Lijing Wang 《International journal of biological sciences》2015,11(5):595-603
Pancreatic islet β cell tumor is the most common islet cell tumor. A well-characterized tumor progression in Rip1-Tag2 mice undergoes five stages, involving normal, hyperplasia, angiogenic islets, tumorigenesis and invasive carcinoma. 1H NMR based metabonomics was applied to identify potential biomarkers for monitoring pancreatic islet β cell tumor progression in Rip1-Tag2 mice. Multivariate analysis results showed the serum metabonome at hyperplasia stage shared the similar characteristics with the ones at normal stage as a result of slight proliferation of pancreatic islet β cells. At angiogenic islets stage, the up-regulated glycolysis, disturbed choline and phospholipid metabolism composed the metabolic signature. In addition to the changes mentioned above, several metabolites were identified as early biomarkers for tumorigenesis, including increased methionine, citrate and choline, and reduced acetate, taurine and glucose, which suggested the activated energy and amino acid metabolism. All the changes were aggravated at invasive carcinoma stage, coupled with notable changes in alanine, glutamate and glycine. Moreover, the distinct metabolic phenotype was found associated with the implanting of SV40 large T antigen in Rip1-Tag2 mice. The combined metabolic and multivariate statistics approach provides a robust method for screening the biomarkers of disease progression and examining the association between gene and metabolism. 相似文献
996.
Zen-Kong Dai Yu-Wei Liu Jong-Hau Hsu Jwu-Lai Yeh Ing-Jun Chen Jiunn-Ren Wu Bin-Nan Wu 《International journal of biological sciences》2015,11(6):633-642
Serotonin (5-hydroxytryptamine, 5-HT) is a potent pulmonary vasoconstrictor that promotes pulmonary artery smooth muscle cell (PASMC) proliferation. 5-HT-induced K+ channel inhibition increases [Ca2+]i in PASMCs, which is a major trigger for pulmonary vasoconstriction and development of pulmonary arterial hypertension (PAH). This study investigated whether KMUP-1 reduces pulmonary vasoconstriction in isolated pulmonary arteries (PAs) and attenuates 5-HT-inhibited K+ channel activities in PASMCs. In endothelium-denuded PA rings, KMUP-1 (1 μM) dose-dependently reduced 5-HT (100 μM) mediated contractile responses. Responses to KMUP-1 were reversed by K+ channel inhibitors (TEA, 10 mM, 4-aminopyridine, 5 mM, and paxilline, 10 μM). In primary PASMCs, KMUP-1 also dose-dependently restored 5-HT-inhibited voltage-gated K+-channel (Kv1.5 and Kv2.1) and large-conductance Ca2+-activated K+-channel (BKCa) proteins, as confirmed by immunofluorescent staining. Furthermore, 5-HT (10 μM)-inhibited Kv1.5 protein was unaffected by the PKA inhibitor KT5720 (1 μM) and the PKC activator PMA (1 μM), but these effects were reversed by KMUP-1 (1 μM), 8-Br-cAMP (100 μM), chelerythrine (1 μM), and KMUP-1 combined with a PKA/PKC activator or inhibitor. Notably, KMUP-1 reversed 5-HT-inhibited Kv1.5 protein and this response was significantly attenuated by co-incubation with the PKC activator PMA, suggesting that 5-HT-mediated PKC signaling can be modulated by KMUP-1. In conclusion, KMUP-1 ameliorates 5-HT-induced vasoconstriction and K+-channel inhibition through the PKC pathway, which could be valuable to prevent the development of PAH. 相似文献
997.
Cui-Li Zhang Tao Zeng Xiu-Lan Zhao Ke-Qin Xie 《International journal of biological sciences》2015,11(6):643-651
To explore the underlying mechanisms for the protective effects of garlic oil (GO) against nitrosodiethylamine (NDEA)-induced hepatocarcinoma, 60 male Wistar rats were randomized into 4 groups (n=15): control group, NDEA group, and two GO plus NDEA groups. The rats in GO plus NDEA groups were pretreated with GO (20 or 40 mg/kg) for 7 days. Then, all rats except those in control group were gavaged with NDEA for 20 weeks, and the rats in GO plus NDEA groups were continuously administered with GO. The results showed that GO co-treatment significantly suppressed the NDEA-induced increases of alpha fetal protein (AFP) level in serum, nuclear atypia in H&E staining, sirius red-positive areas and proliferating cell nuclear antigen (PCNA) expression. The molecular mechanisms exploration revealed that the protein levels of phosphatidylinositol 3 kinase (PI3K)-p85, PI3K-p110, total AKT, p-AKT (Ser473) and p-AKT (Thr308) in the liver of NDEA group rats were higher than those in control group rats. In addition, NDEA treatment induced IκB degradation and NF-κB p65 phosphorylation, and up-regulated the protein levels of downstream pro-inflammatory mediators. GO co-treatment significantly reversed all the above adverse effects induced by NDEA. These results suggested that the protective effects of GO against NDEA-induced hepatocarcinoma might be associated with the suppression of PI3K- AKT-NF-κB pathway. 相似文献
998.
999.
Anna Stincone Alessandro Prigione Thorsten Cramer Mirjam M. C. Wamelink Kate Campbell Eric Cheung Viridiana Olin‐Sandoval Nana‐Maria Grüning Antje Krüger Mohammad Tauqeer Alam Markus A. Keller Michael Breitenbach Kevin M. Brindle Joshua D. Rabinowitz Markus Ralser 《Biological reviews of the Cambridge Philosophical Society》2015,90(3):927-963
1000.
Greg Hodge Hubertus Jersmann Hai B Tran Mark Holmes Paul N Reynolds Sandra Hodge 《Respiratory research》2015,16(1)