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941.
942.
Despite the fact that marine viruses have been increasingly studied in the last decade, there is little information on viral abundance and distribution on a global scale. In this study, we report on a global-scale survey covering the Pacific, Atlantic, and Indian Oceans on viral distribution using flow cytometry. Viruses were stained with the SYBR Green I, which targets only dsDNA viruses. The average viral abundance was 1.10±0.73×107 ml−1 in global surface oceans and decreased from the areas with high chlorophyll concentration (on average, 1.47±0.78×107 ml−1) to the oligotrophic subtropical gyres (on average, 6.34±2.18×106 ml−1). On a large-spatial-scale, viruses displayed significant relationships with both heterotrophic and autotrophic picoplankton abundance, suggesting that viral distribution is dependent on their host cell abundance. Our study provided a basin scale pattern of marine viral distributions and their relationship with major host cells, indicating that viruses play a significant role in the global marine ecosystem. 相似文献
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Fenqing Shang Jiao Zhang Zhao Li Jin Zhang Yanjun Yin Yaqiong Wang Traci L. Marin Brendan Gongol Han Xiao You-yi Zhang Zhen Chen John Y-J Shyy Ting Lei 《PloS one》2016,11(3)
Hyperglycemia and hypertension impair endothelial function in part through oxidative stress-activated poly (ADP-ribose) polymerase 1 (PARP1). Biguanides and angiotensin II receptor blockers (ARBs) such as metformin and telmisartan have a vascular protective effect. We used cultured vascular endothelial cells (ECs), diabetic and hypertensive rodent models, and AMPKα2-knockout mice to investigate whether metformin and telmisartan have a beneficial effect on the endothelium via AMP-activated protein kinase (AMPK) phosphorylation of PARP1 and thus inhibition of PARP1 activity. The results showed that metformin and telmisartan, but not glipizide and metoprolol, activated AMPK, which phosphorylated PARP1 Ser-177 in cultured ECs and the vascular wall of rodent models. Experiments using phosphorylated/de-phosphorylated PARP1 mutants show that AMPK phosphorylation of PARP1 leads to decreased PARP1 activity and attenuated protein poly(ADP-ribosyl)ation (PARylation), but increased endothelial nitric oxide synthase (eNOS) activity and silent mating type information regulation 2 homolog 1 (SIRT1) expression. Taken together, the data presented here suggest biguanides and ARBs have a beneficial effect on the vasculature by the cascade of AMPK phosphorylation of PARP1 to inhibit PARP1 activity and protein PARylation in ECs, thereby mitigating endothelial dysfunction. 相似文献
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948.
Fifty natural Datura populations, belonging to eleven species (D. ceratocaula, D. discolor, D. inoxia, D. kymatocarpa, D. lanosa, D. metel, D. pruinosa, D. quercifolia, D. reburra, D. stramonium, D. wrightii) from Mexico and adjacent USA, were investigated using starch gel electrophoresis. A total of 64 alleles were scored at 17
loci (DIA1, DIA2, GOT1, GOT2, G6PDH, IDH, MDH1, MDH2, MDH3, ME, PGD1, PGD2, PGM1, PGM2, PHI, SAD, SOD). The heterozygosity
among the species ranged from 0.166 (D. ceratocaula) to 0.276 (D. wrightii). Most genetic diversity was found within populations (average Hs=0.242), while values between populations are relatively low (average Dst=0.066, Gst=0.171). The analysis of the genetic distance
suggested new taxonomic relationships among the species. Rather than supporting the conventional infrageneric classification
with three sections, the results revealed that the herbaceous members of the genus Datura form four groups. One group included four of the eight species of the section Dutra and was more similar to the section Ceratocaulis than it was to the other group that contained the remaining taxa of Dutra.
Received February 13, 2001 Accepted December 25, 2001 相似文献
949.
Francisco J. Calero-Cuenca Daniel S. Osorio Sofia Carvalho-Marques Sreerama Chaitanya Sridhara Luis M. Oliveira Yue Jiao Jheimmy Diaz Cátia S. Janota Bruno Cadot Edgar R. Gomes 《Current biology : CB》2021,31(7):1521-1530.e8
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950.
Sheng-Wei Zhu Peng Gao Jing-San Sun Hai-Hua Wang Xiao-Min Luo Ming-Yu Jiao Zhi-Yong Wang Gui-Xian Xia 《In vitro cellular & developmental biology. Plant》2006,42(5):439-444
Summary This study reports an Agrobacterium-mediated transformation of green-colored cotton (Gossypium hirsutum L.). A tissue culture procedure was optimized to induce callus formation from hypocotyl explants and subsequent differentiation
into the embryogenic type. Callus formation could be induced by growing explants on Murashige and Skoog medium containing
2,4-dichlorophenoxyacetic acid and kinetin. Among the four genotypes studied, embryogenic calli and plant regeneration were
observed only in var. G9803. Agrobacterium-mediated transformation of G9803 with the fiber-specific expansin gene GhExpl was achieved based on the establishment of these tissue culture methods. A total of 32 individual regenerants resistant to
kanamycin were generated within 7 mo., with a transformation frequency of 17.8%. Transformation was confirmed by Southern
blot analysis and RT-PCR. These results represent the first step towards genetic manipulation of the colors and fiber quality
of green-colored cottons by biotechnology.
These authors contributed equally to this work 相似文献