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91.
Use of glnQ as a Counterselectable Marker for Creation of Allelic Exchange Mutations in Group B Streptococci 总被引:1,自引:0,他引:1 下载免费PDF全文
Glen S. Tamura Debra S. Bratt Harry H. Yim Aphakorn Nittayajarn 《Applied microbiology》2005,71(1):587-590
Efficient allelic exchange mutagenesis in group B streptococci (GBS) has been hampered by the lack of a counterselectable marker system. Growth inhibition of GBS by the glutamine analog gamma-glutamyl hydrazide requires glnQ. We have used this phenomenon to create a counterselectable marker system for efficient selection of allelic exchange mutants in GBS. 相似文献
92.
Babita Paudel Hari Datta Bhattarai Jin Sung Lee Soon Gyu Hong Hyun Woung Shin Joung Han Yim 《Polar Biology》2008,31(5):605-608
Antioxidant agents prevent reactive oxygen species, which can cause degenerative diseases. Natural antioxidants are preferred
over many synthetic antioxidants, which can be toxic, for therapeutic applications. Five lichen species were collected from
King George Island, Antarctica. Antioxidant activities as assessed by DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical and
ABTS•+ [2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonate)] radical scavenging capacities were determined and compared with those
of commercial standards BHA (butylated hydroxyanisole) and trolox [(±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic
acid]. The results indicated that two lichens exhibited comparatively high antioxidant activities with the remaining three
exhibiting less activity. The antioxidant activity was concentration-dependent. When compared, the antioxidant activity of
crude extracts from polar lichens to previously published data for tropical and temperate lichen species, we concluded that
lichens of Antarctic origin may be the potent sources of strong antioxidant agents. Such species should be explored as novel
sources of effective antioxidant metabolites. 相似文献
93.
The use of luxABCDE (lux) offers certain advantages over other reporters, such as: lacZ and xylE. It is real time and its signal generation is produced without the requirement for any additional substrates. In some bacteria such as Staphylococcus spp, light production by luciferase is restricted because of a limited availability of endogenous substrates such as fatty acid aldehyde. We describe the construction of promoterless-lux cloning vectors, pGYlux and pAmilux. S. aureus carrying B. subtilis xyl/tetO promoter fused to the lux genes of pGYlux gave up to a 2.5-fold enhancement of luminescence over S. aureus carrying the xyl/tetO promoter fused to lux genes of the previously published parent vector pAL2. Furthermore, pAmilux showed a 6-fold enhancement of lux expression when compared to pGYlux in S. aureus. This was achieved by cloning the constitutive ami promoter upstream of the luxCDE genes to increase endogenous fatty acid aldehyde production while maintaining its reporter functionality by fusing promoters to the luxAB genes. 相似文献
94.
Woo-Jong Yim Selvaraj Poonguzhali Munusamy Madhaiyan Pitchai Palaniappan M. A. Siddikee Tongmin Sa 《Journal of microbiology (Seoul, Korea)》2009,47(2):147-155
Diazotrophic bacteria isolated from the rhizosphere of Chinese cabbage were assessed for other plant growth promoting characteristics
viz., production of IAA, ethylene, ACC deaminase, phosphate solubilization, and gnotobiotic root elongation. Their effect on inoculation
to Chinese cabbage was also observed under growth chamber conditions. A total of 19 strains that showed higher nitrogenase
activity identified by 16S rRNA gene sequence analysis were found to be the members of the genera Pseudomonas and Agrobacterium belonging to α- and γ-Proteobacteria groups. These strains were also efficient in producing IAA and ACC deaminase though they produced low levels of ethylene
and no phosphate solubilization. In addition, inoculation of selected diazotrophic bacterial strains significantly increased
seedling length, dry weight, and total nitrogen when compared to uninoculated control. The colonization of crop plants by
diazotrophic bacteria can be affected by many biotic and abiotic factors, and further studies are oriented towards investigating
the factors that could influence the establishment of a selected bacterial community. 相似文献
95.
96.
CRISPR-Cas9 Knockin Mice for Genome Editing and Cancer Modeling 总被引:2,自引:0,他引:2
Randall J. Platt Sidi Chen Yang Zhou Michael J. Yim Lukasz Swiech Hannah R. Kempton James E. Dahlman Oren Parnas Thomas M. Eisenhaure Marko Jovanovic Daniel B. Graham Siddharth Jhunjhunwala Matthias Heidenreich Ramnik J. Xavier Robert Langer Daniel G. Anderson Nir Hacohen Aviv Regev Guoping Feng Phillip A. Sharp Feng Zhang 《Cell》2014
97.
Protein p63 is a key regulator in cell proliferation and cell differentiation in stratified squamous epithelium. ΔNp63α is the most commonly expressed p63 isoform, which is often overexpressed in human tumor. In the present work we report the potential involvement of ΔNp63α in cell cycle regulation. ΔNp63α accumulated in mitotic cells but its expression decreased during mitotic exit. Moreover, ΔNp63α knockdown promoted mitotic exit. ΔNp63α shares a conserved destruction box (D-box) motif with other potential targets of the Anaphase-Promoting Complex/Cyclosome (APC/C). Overexpression of APC/C coactivator Cdh1 destabilized ΔNp63α. Our results suggest that ΔNp63α level is cell cycle-regulated and may play a role in the regulation of mitotic exit. 相似文献
98.
We investigated the function of homeodomain-containing protein Hbx4 in Dictyostelium discoideum. Hbx4-overexpressing cells (Hbx4(OE)) displayed defects in growth rate and cytokinesis and showed differences in slug motility and cell-type proportioning from KAx3. Furthermore, the overexpression of Hbx4 inhibited the induction of cadA, which encoded the Ca(2+)-dependent cell adhesion molecule DdCAD-1, despite expression of csaA and gpaB. The electrophoretic mobility shift assay showed that the promoter of cadA contained the Hbx4-binding site. Moreover, constitutively expressed DdCAD-1 in Hbx4(OE) rescued the defects in cytokinesis and development. These results suggest that Hbx4 modulates DdCAD-1-mediated cytokinesis and cell-type proportioning. 相似文献
99.
100.
Kenjale AA Ham KL Stabler T Robbins JL Johnson JL Vanbruggen M Privette G Yim E Kraus WE Allen JD 《Journal of applied physiology (Bethesda, Md. : 1985)》2011,110(6):1582-1591
Peripheral arterial disease (PAD) results in a failure to adequately supply blood and oxygen (O(2)) to working tissues and presents as claudication pain during walking. Nitric oxide (NO) bioavailability is essential for vascular health and function. Plasma nitrite (NO(2)(-)) is a marker of vascular NO production but may also be a protected circulating "source" that can be converted to NO during hypoxic conditions, possibly aiding perfusion. We hypothesized that dietary supplementation of inorganic nitrate in the form of beetroot (BR) juice would increase plasma NO(2)(-) concentration, increase exercise tolerance, and decrease gastrocnemius fractional O(2) extraction, compared with placebo (PL). This was a randomized, open-label, crossover study. At each visit, subjects (n = 8) underwent resting blood draws, followed by consumption of 500 ml BR or PL and subsequent blood draws prior to, during, and following a maximal cardiopulmonary exercise (CPX) test. Gastrocnemius oxygenation during the CPX was measured by near-infrared spectroscopy. There were no changes from rest for [NO(2)(-)] (152 ± 72 nM) following PL. BR increased plasma [NO(2)(-)] after 3 h (943 ± 826 nM; P ≤ 0.01). Subjects walked 18% longer before the onset of claudication pain (183 ± 84 s vs. 215 ± 99 s; P ≤ 0.01) and had a 17% longer peak walking time (467 ± 223 s vs. 533 ± 233 s; P ≤ 0.05) following BR vs. PL. Gastrocnemius tissue fractional O(2) extraction was lower during exercise following BR (7.3 ± 6.2 vs. 10.4 ± 6.1 arbitrary units; P ≤ 0.01). Diastolic blood pressure was lower in the BR group at rest and during CPX testing (P ≤ 0.05). These findings support the hypothesis that NO(2)(-)-related NO signaling increases peripheral tissue oxygenation in areas of hypoxia and increases exercise tolerance in PAD. 相似文献