Gene Expression of Mouse Hippocampal Stem Cells Grown in a Galactose-Derived Molecular Gel Compared to In Vivo and Neurospheres

Background: N-heptyl-D-galactonamide (GalC7) is a small synthetic carbohydrate derivative that forms a biocompatible supramolecular hydrogel. In this study, the objective was to analyze more in-depth how neural cells differentiate in contact with GalC7. Method: Direct (ex vivo) cells of the fresh hippocampus and culture (In vitro) of the primary cells were investigated. In vitro, investigation performed under three conditions: on culture in neurospheres for 19 days, on culture in GalC7 gel for 7 days, and on culture in both neurospheres and GalC7 gel. Total RNA was isolated with TRIzol from each group, Sox8, Sox9, Sox10, Dcx, and Neurod1 expression levels were measured by qPCR. Result: Sox8 and Sox10, oligodendrocyte markers, and Sox9, an astrocyte marker, were expressed at a much higher level after 7 days of culture in GalC7 hydrogel compared to all other conditions. Dcx, a marker of neurogenesis, and Neurod1, a marker of neuronal differentiation, were expressed at better levels in the GalC7 gel culture compared to the neurosphere. Conclusions: These results show that the GalC7 hydrogel brings different and interesting conditions for inducing the differentiation and maturation of neural progenitor cells compared with polymer-based scaffolds or cell-only conditions. The differences observed open new perspectives in tissue engineering, induction, and transcript analysis.

Comparative physiological and transcriptomic analysis of pear leaves under distinct training systems

Canopy architecture is critical in determining the light interception and distribution, and subsequently the photosynthetic efficiency and productivity. However, the physiological responses and molecular mechanisms by which pear canopy architectural traits impact on photosynthesis remain poorly understood. Here, physiological investigations coupled with comparative transcriptomic analyses were performed in pear leaves under distinct training systems. Compared with traditional freestanding system, flat-type trellis system (DP) showed higher net photosynthetic rate (PN) levels at the most time points throughout the entire monitored period, especially for the interior of the canopy in sunny side. Gene ontology analysis revealed that photosynthesis, carbohydrate derivative catabolic process and fatty acid metabolic process were over-represented in leaves of DP system with open-canopy characteristics. Weighted gene co-expression network analysis uncovered a significant network module positive correlated with PN value. The hub genes (PpFKF1 and PpPRR5) of the module were enriched in circadian rhythm pathway, suggesting a functional role for circadian clock genes in mediating photosynthetic performance under distinct training systems. These results draw a link between pear photosynthetic response and specific canopy architectural traits, and highlight light harvesting and circadian clock network as potential targets for the input signals from the fluctuating light availability under distinct training systems.

Progress in the Synthesis of 2,3-unsaturated Glycosides

The substitution reaction of glycal (1,2-unsaturated cyclic carbohydrate derivative) at C1 by allyl rearrangement in the presence of a catalyst is called Ferrier type-I rearrangement. 2,3-Unsaturated glycosides are usually obtained from glycals through Ferrier type-I rearrangement, and their potential biological activities have gradually attracted widespread attention of researchers. This review summarizes recent advances (2009- present) in the application of various types of catalysts to Ferrier type-I rearrangement reactions, including their synthesis, mechanism, and application of 2, 3-unsaturated glycosides.

Aspects of determining biomass-based levoglucosenone by UHPLC–UV in aqueous samples

The depletion of fossil resources and concerns about the environment encourage the search for renewable biomass-based chemicals with broad applications. Levoglucosenone (LGO) is a carbohydrate derivative obtained by the pyrolysis of cellulose containing raw materials. Because of its two chiral centres LGO is particularly appealing to the organic synthesis industry, therefore improved ways of producing LGO are continuously investigated. This study deals with the quality control of the LGO containing pyrolysis products by modern UHPLC–UV methods. Acceptable chromatographic separation of LGO could be achieved in most samples of pyrolysis products obtained from birch (Betula pendula) wood. However, a significant degradation of LGO was observed in aqueous solutions, which needs to be taken into consideration both when performing analysis, as well as during the storage of the pyrolysis products which are generally recovered from the pyrolysis reactor as a water condensate. The degradation rate of LGO in a water/acetonitrile solution, which corresponds with the mobile phase of the UHPLC method, at 5°C was 1.8% a day. Even faster degradation occurred in samples without the addition of acetonitrile.

Comparative analysis of the Accelerated Aged seed transcriptome profiles of maize CSSLs (I178 and X178)

Seed longevity is one of the most essential characters of seed quality. Two Chromosome segment substitution lines (CSSL) I178 and X178 with significant difference on seed longevity were subjected to transcriptome sequencing before (0d-AA) and after five days of accelerated ageing (5d-AA) treatments. Compared to the non-accelerated ageing treatment (0d-AA), 286 and 220 differential expressed genes (DEGs) were identified in I178 and X178, respectively Among those, 98 DEGs were detected in both I178 and X178 after 5d-AA, Enriched GO terms included cellular components of cell part, intracellular part, organelle and membrane etc., including carbohydrate derivative catabolic process, carbohydrate synthesis, sugar isomerase (SIS) family protein etc. Transcriptome analysis of I178 and X178 showed that Alternative splicing (AS) occurs in 63.6% of the expressed genes in all samples. Only 381 genes specifically occurred AS in I178 and X178 after 5d-AA, mostly enriched in nucleotide and nucleoside binding. Combined with the reported QTL mapping result, the DEG and the AS information, 13 DEGs in the mapping intervals and 7 AS-DEGs were potential candidates may directly or indirectly associated to seed ageing.

Working in the Dark

Three turns of the Calvin cycle (Figure 11.1), allow the conversion of three (3) equivalents of carbon dioxide (CO2) (i.e., 3 C1 units) along with three (3) equivalents of the five-carbon carbohydrate derivative, ribulose-1,5-bisphosphate (i.e., 3 C5 units) to yield three (3) not yet isolated six-carbon adducts, 2-carboxy-3-ketoribitol-1,5-bisphosphate (3 C1 + 3 C5 = 3 C6) to form. The three (3) C6 species then undergo fragmentation to yield six (6) equivalents of the three (3) carbon dihydroxy monocarboxylate, 3-phosphoglycerate (i.e., 3 C6 = 6 C3). A cartoon representation of this process is shown in Scheme 11.1 for one of the three CO2 units. Of the six (6) three-carbon unit equivalents, five (5) are used to regenerate three (3) equiv¬alents of ribulose-1,5-bisphosphate (i.e., 5 C3 = 3 C5), while the sixth three- carbon fragment is now available to combine with another to make a six (6) carbon sugar (2 C3 = 1 C6) such as glucose (C6H12O6) (Figure 11.2). Additionally, as shown in Figure 11.3, 3-phosphoglycerate can be used to make other small compound building blocks such as glyceric acid, lactic acid, pyruvic acid and even acetic acid (after decarboxylation). Ribulose- 1,5-bisphosphate (often abbreviated as RuBP), using the enzyme ribulose- 1,5- bisphosphate carboxylase (EC 4.1.1.39, carboxydismutase, rubisco), catalyzes the Mg2+- dependent conversion of the 1,5- bisphosphate ester of the carbohydrate ribulose with carbon dioxide (CO2) to produce two (2) equivalents of 3- phosphoglycerate (PGA). As shown in the Schemes 11.1 and 11.2. A hypothetical the six carbon intermediate, 2- carboxy- 3- ketoribitol- 1,5- bisphosphate, is often written. It is important to keep in mind that we want the 3- phosphoglycerate for purposes of construction of other important compounds. But, as noted above, three turns of the cycle are necessary to produce six (6) equivalents of 3- phosphoglycerate, and five (5) of them are reused in making the three (3) ribulose- 1,5- bisphosphates necessary to turn the cycle three (3) times.