Effects of Different Light Qualities on Activity and Gene Expression of Caspase-like Proteases in Tobacco Leaves

[Objective] The study aimed to investigate the activity and gene expression of caspase-like proteases in tobacco leaves growing under different light qualities. [Method] By covering tobacco plants with white, red, yellow, blue and purple films to obtain different light quality, the changes of chlorophyll content, activity and gene expression of caspase-like proteases in the tobacco leaves were studied. [Results] Compared with treatments of white, red and yellow film, blue and purple films delayed the decrease of chlorophyll content and senescence of tobacco leaves at the late growth stage, and relatively lowered the activity and gene expression of caspase-like proteases during growth, development and senescence periods. [Conclusion] Different light qualities exhibited various effects on the growth, development and senescence of tobacco leaves, possibly by affecting the activity and gene expression of caspase-like proteases to some extent.

Kinetics of High Cell Density Fed-batch Culture of Recombinant Escherichia coli Producing Human-like Collagen

The kinetics of batch and fed-batch cultures of recombinant Escherichia coli producing human-like collagen was investigated. In the batch culture, a kinetic model of a simple growth-association system was concluded without consideration of cell endogeneous metabolism. The cell lag time, the maximum specific growth rate and Yx/s were determined as 1.75h, 0.65h^-1 and 0.51g·g^-1, respectively. In the fed-batch culture, different specific growth rates were set at （0.15, 0.2, 0.25h^-1） by the method of pseudo-exponential feeding, and the expressions for the specific rate of substrate consumption, the growth kinetics and the product formation kinetics of each phase were obtained. The result shows that the concentrations of cell and product can reach 77.5g·L^-1 and 10.2g·L^-1 respectively. The modal predictions are in good agreement with the experimental data.

Application of VP1 Protein to Develop Monoclonal Antibody against Foot-and-mouth Disease Virus Asia1 Type

In order to develop an anti-FMDV Asial type monoclonal antibody （mAb）, BABL/c mice were immunized with recombinant FMDV VP1 protein. Three mAbs, 1B8, 5El and 5E2, were then further optimized. The result indicated that prepared anti-FMDV Asial mAbs had no cross-reactivity with Swine vesicular disease （SVD） and FMDV O, A and C type antigen. Their titers in abdomen liquor were 1：5×10^6, 1：2×10^6 and 1：5×10^6, respectively. 1B8 was found to be of IgG1 subtype, 5El and 5E2 belonged to IgG2b subtype. In this study, the prepared mAbs are specific for detecting FMDV type Asia1, and is potentially useful for pen-side diagnosis.

Modulation of mitochondrial respiration underpins neuronal differentiation enhanced by lutein

Lutein is a dietary carotenoid of particular nutritional interest as it is preferentially taken up by neural tissues. Often linked with beneficial effects on vision, a broader role for lutein in neuronal differentiation has emerged recently, although the underlying mechanisms for these effects are not yet dear. The purpose of this study was to investigate the effect of lutein on neuronal differentiation and explore the associated underpinning mechanisms. We found that lutein treatment enhanced the differentiation of SH-SYSY cells, specifically increasing neuronal arborization and expression of the neuronal process filament protein microtubule-associated protein 2. This effect was mediated by the intracellular phosphoinositide-3-kinase （PI3K） signaling pathway. While PI3K activity is a known trigger of neuronal differentiation, more recently it has also been shown to modulate the metabolic state of cells. Our analysis of bioenergetics found that lutein treatment increased glucose consumption, rates of glycolysis and enhanced respiratory activity of mitochondrial complexes. Concomitantly, the generation of reactive oxygen species was increased （con- sistent with previous reports that reactive oxygen species promote neuronal differentiation）, as well as the production of the key metabolic intermediate acetyl-CoA, an essential determinant of epigenetic status in the cell. We suggest that lutein-stimulated neuronal differentiation is mediated by PI3K-dependent modulation of mitochondrial respiration and signaling, and that the consequential metabolic shifts initiate epigenetically dependent transcriptomic reprogramming in support of this morphogenesis. These obser- vations support the potential importance of micronutrients supplementation to neurogenesis, both during normal development and in regenerative repair.

Detection and Analysis of an Estrous－associated Oviductal Glycoprotein DNA Fragment from Primates by PCR

DNA was extracted from lymphocytes of primates and PCR was used to amplify the estrous-associated glycoprotein DNA fragment. 537 kb DNA fragments from crab eating macaque were detected. Sequences from chimpanzee, orangutan and human were also amplified, but they were shorter than predicted. We were unable to amplify sequences from spider monkey, salmon, several rodents, bandicoot, sheep and pig . Analysis of the restriction map revealed several conserved RE sites in the amplified sequences of the primates. The results support the view that monkey has more close relationship with human than any other species at molecular level.