VdERG2 was involved in ergosterol biosynthesis, nutritional differentiation and virulence of Verticillium dahliae.

The ergosterol biosynthesis pathway plays an important role in model pathogenic bacteria Saccharomyces cerevisiae, but little is known about the biosynthesis of ergosterol in the pathogenic fungus Verticillium dahliae. In this study, we identified the VdERG2 gene encoding sterol C-8 isomerase from V. dahliae and investigated its function in virulence by generating gene deletion mutants (ΔVdERG2) and complemented mutants (C-ΔVdERG2). Knockout of VdERG2 reduced ergosterol content. The conidial germination rate and conidial yield of ΔVdERG2 significantly decreased and abnormal conidia were produced. In spite of VdERG2 did not affect the utilization of carbon sources by V. dahliae, but the melanin production of ΔVdERG2 was decreased in cellulose and pectin were used as the sole carbon sources. Furthermore, the ΔVdERG2 mutants produced less microsclerotia and melanin with a significant decrease in the expression of microsclerotia and melanin-related genes VaflM, Vayg1, VDH1, VdLAC, VdSCD and VT4HR. In addition, mutants ΔVdERG2 were very sensitive to congo red (CR), sodium dodecyl sulfate (SDS) and hydrogen peroxide (H2O2) stresses, indicating that VdERG2 was involved in the cell wall and oxidative stress response. The absence of VdERG2 weakened the penetration ability of mycelium on cellophane and affected the growth of mycelium. Although ΔVdERG2 could infect cotton, its pathogenicity was significantly impaired. These phenotypic defects in ΔVdERG2 could be complemented by the reintroduction of a full-length VdERG2 gene. In summary, as a single conservative secretory protein, VdERG2 played a crucial role in ergosterol biosynthesis, nutritional differentiation and virulence in V. dahliae.

Isolation, culture, and induced multiple differentiation of Mongolian sheep adipose-derived mesenchymal stem cells.

Adipose-derived mesenchymal stem cells (ADSC) are adult pluripotent cells and important resources for cell-based therapies of animals. There are presently different kinds of somatic cells used as donor cells for clone successfully. However, studies on somatic cell nuclear transplantation (SCNT) using ADSC as donor cells from Mongolian sheep have not been reported up to now. This study tested optimal methods of isolating, purifying, and proliferating Mongolian sheep ADSC, and determine their multiple differentiation potentiality. Adipose tissue was removed from approximately 2-year-old sheep and ADSC were harvested by pancreatic enzyme decomposition and adherent culture method. The growth curves of the Passages 1, 5, and 10 cultures were plotted and the exponential growth was determined as a population doubling time of 34.1 h. The expression of OCT4, SOX2, and NANOG genes were increased at Passage 3 (P3) as seen by reverse transcription polymerase chain reaction (RT-PCR) analysis. ADSC from Passage 3 were induced to undergo neurogenesis and form cardiomyocytes and pancreatic islet-like cells under inductive environments in vitro. The differentiation properties of cardiomyocytes and islet-like cells were confirmed by histological staining with toluidine blue, periodic acid-Schiff, and dithizone. The expression of specific genes in these cells were also detected by RT-PCR. Our study results confirm that isolated cells were indeed ADSC and may provide valuable materials for somatic cell clone and transgenic research.

New Cyclic Diarylheptanoids from Platycarya strobilacea.

Five new cyclic diarylheptanoids (platycary A-E, compounds 1-5) and three previously identified analogues (i.e., phttyearynol (compound 6), myricatomentogenin (compound 7), and juglanin D (compound 8)) were isolated from the stem bark of Platycarya strobilacea. The structures of these compounds were determined using NMR, HRESIMS, and electronic circular dichroism (ECD) data. The cytotoxicity of compounds 1-5 and their ability to inhibit nitric oxide (NO) production, as well as protect against the corticosterone-induced apoptosis of Pheochromocytoma (PC12) cells, were evaluated in vitro using the appropriate bioassays. Compounds 1 and 2 significantly inhibited the corticosterone-induced apoptosis of PC12 cells at a concentration of 20 µΜ.