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Previously, we created miR-137 overexpressing transgenic mice that produced lighten color phenotypes including gray mice phenotype. However, the miR-137 functional role in coat color regulation is still not well understood. In this study, the quantity of melanin granule and the relative expression of TYRP2 in gray miR-137 overexpression transgenic mouse skin were significantly lower than that in C57BL/6J black mouse skin. The mRNA and protein expression level of c-Kit and c-Kit downstream gene Tyrp2 in miR-137 expression plasmid-transfected melanocytes were significantly down-regulated comparing with that of the control melanocytes. In melanocytes, miR-137 overexpression could decrease the enhanced expression of c-Kit and Tyrp2 and the increased melanin production caused by UV treatment. The target relationship of miR-137 and c-Kit was identified by luciferase assay. The results suggest that miR-137 could inhibit melanogenesis in mouse skin melanocytes by repressing the expression of c-Kit and Tyrp2 in SCF/c-Kit signaling pathway. 相似文献
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Jiang?Tian Chenlei?Yu Yingwen?Xue Ruixue?Zhao Jing?Wang Lanzhou?ChenEmail author 《Biodegradation》2016,27(4-6):265-276
The novel trichlorfon (TCF)-degrading bacterium PA F-3, identified as Bacillus tequilensis, was isolated from pesticide-polluted soils by using an effective screening and domesticating procedure. The TCF biodegradation pathways of PA F-3 were also systematically elucidated. As revealed by high-performance liquid chromatography, the TCF residues in the mineral salt medium demonstrated that PA F-3 can utilize TCF as its sole carbon source and reach the highest degradation of 71.1 % at an initial TCF concentration of 200 mg/L within 5 days. The TCF degradation conditions were optimized using response surface methodology as follows: temperature, 28 °C; inoculum amount, 4 %; and initial TCF concentration, 125 mg/L. Biodegradation treatments supplemented with exogenous carbon sources and yeast extract markedly increased the microbial dry weights and TCF-degrading performance of PA F-3, respectively. Meanwhile, five metabolic products of TCF were identified through gas chromatography/mass spectrometry, and a biodegradation pathway was proposed. Results indicated that deoxidation and dehydration (including the cleavage of the P–C phosphonate bond and the C–O bond) were the preferred metabolic reactions of TCF in this TCF-degrading bacterium. 相似文献
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To understand the circadian rhythms of the glucose metabolism and related hormones in desert reptiles, we studied the daily changes in plasma leptin, insulin, and glucose in the toad-headed lizard, Phrynocephalus versicolor, in the semi-desert of the Alashan Plateau. Blood samples were obtained from groups of 20 lizards (about equal sex ratio for each group) at 4-h intervals throughout a 24-h period. Leptin, insulin, and glucose levels were determined using ELISA, RIA, and the glucose oxidase method, respectively. Ambient temperature and humidity were also measured when the blood samples were taken. We found that: (1) there was a significant difference in plasma leptin concentrations at different times of day; (2) no significant circadian rhythm could be measured for plasma insulin and glucose; (3) ambient temperature, humidity, and body condition had no significant effect on plasma leptin, insulin, and glucose levels; and (4) there were significant correlations between plasma glucose concentrations and leptin concentrations 8 h later, and between insulin concentrations and leptin concentration 8–12 h later. These results suggested that the secretions of leptin and insulin played an important role in glucose metabolism in reptiles in an arid environment. 相似文献
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Effect of host plants on the infectivity of nucleopolyhedrovirus to Spodoptera exigua larvae 下载免费PDF全文
Previous studies have shown that the infectivity of baculovirus to herbivores is affected by phytochemicals ingested during the acquisition of viral inoculum on the foliage of host plants. Here, we measured the effects of 14 host plant species on the infectivity of Spodoptera exigua nucleopolyhedrovirus (SeNPV) to its larvae. The order of the LD50 values of SeNPV among the host plants was Ipomoea aquatica > Brassica oleracea > Raphanus sativus > Amaranthus tricolor > Spinacia oleracea > Vigna unguiculata > Solanum melongena > Capsicum annuum > Apium graveolens > Allium fistulosum > Lactuca sativa > Brassica chinensis > Zea mays > Glycine max, with 940.1 ± 2.26, 424.0 ± 0.60, 295.2 ± 1.13, 147.3 ± 0.63, 138.6 ± 0.22, 119.9 ± 0.07, 119.8 ± 0.02, 109.2 ± 0.18, 104.8 ± 0.62, 102.1 ± 0.66, 97.9 ± 0.22, 89.9 ± 0.32, 79.0 ± 0.13 and 64.0 ± 0.38 OBs per larva, respectively, and the values of mean time to death of virus‐infected larvae were 6.21 ± 0.11, 7.12 ± 0.10, 7.33 ± 0.21, 6.97 ± 0.02, 7.06 ± 0.01, 7.29 ± 0.03, 7.32 ± 0.05, 7.07 ± 0.08, 7.24 ± 0.11, 7.09 ± 0.13, 7.50 ± 0.06, 7.23 ± 0.01, 7.30 ± 0.02 and 7.19 ± 0.07 days, respectively. The mean time to death of larvae decreased with increasing viral dose, and corrected mortality decreased as the larval mean time to death increased. These findings have significance for understanding the effects of host plants on the infectivity of baculovirus to noctuids. 相似文献