[Response of Topsoil Fungal Community Structure to Soil Improvement Measures in Degraded Forest of Red Soil Region].

Soil fungal community structure and diversity are highly sensitive to variations in the external environment, as well as soil improvement measures. In order to clarify the effects of soil improvement measures on topsoil fertility or quality, a field experiment was conducted in eroded forest of a red soil region. Organic fertilizer, biochar, and lime+microbial fertilizer were added to the topsoil, respectively. After four years, the chemistry properties and nutrients in the topsoil were measured, and the diversity and composition of fungi were analyzed. The results showed that the additions of organic fertilizer, biochar, and lime+microbial fertilizer reduced fungal richness in topsoil, compared to that with no fertilizer addition (CK). Among them, lime+microbial fertilizer had the most negative effect on fungal richness. The three soil improvement measures also affected the diversity of topsoil fungi, but the impacts were not significant. The dominant fungal phyla in the topsoil were Ascomycota (31.29%-46.55%) and Basidiomycota (30.07%-70.71%), and the dominant fungal genera were Amphinema and Archaeorhizomyces. The effects of soil improvement measures on fungal community structure in the topsoil were different; organic fertilizer increased the relative abundance of Ascomycetes and Archaeopteroides, and biochar enhanced the relative abundance of Basidiomycetes and Archaeopteroides, whereas lime+microbial fertilizer improved the relative abundance of Basidiomycetes and Archaeopteroides. Fungal diversity and community structure in the topsoil was affected by edaphic factors, and fungal richness was regulated by pH value, whereas fungal community structure was influenced by pH, total nitrogen, and organic carbon. This study provides scientific guidance for soil improvement and ecological restoration below the canopy in eroded forests of red soil regions.

[Rhesus monkey (Macaca mulatta) muller cells exhibit retinal stem/progenitor cell features in vitro].

Recent evidences indicate that retinal muller cells exhibit retinal progenitor characteristics under certain condition in chick, rat and human. However, there is no report on nonhuman primate, a close relative to human. In this study, we first established a muller cell line of rhesus monkey expressing GS, vimentin, CRALBP, EGFR, barely GFAP, which resemble the expression profile of human muller cells, differ from that of rodent. Expression of pax6, nestin, sox2, otx2, six6, and six3 was detected after one week culture in neural stem cell medium. Further culture with retinoic acid induced some cells differentiate toward neuron. These results suggest that primate muller cell is capable of dedifferentiating to retinal progenitors, which may serve as a potential cell source for cell therapy to treat retinal degenerative diseases.

Notch signaling dependent differentiation of cholangiocyte-like cells from rhesus monkey embryonic stem cells.

Rhesus monkey embryonic stem (rES) cells have similar characteristics to human ES cells, and might be useful as a substitute model for preclinical research. Notch signaling is involved in the formation of bile ducts, which are composed of cholangiocytes. However, little is known about the role of Notch signaling in cholangiocytic commitment of ES cells. We analyzed the effect of Notch signaling on the induction of cholangiocyte-like cells from rES cells. About 80% of definitive endoderm (DE) cells were generated from rES cells after treatment with activin A. After treatment with BMP4 and FGF1 on matrigel coated wells in serum-free medium, rES-derived DE gave rise to cholangiocyte-like cells by expression of cholangiocytic specific proteins (CK7, CK18, CK19, CK20, and OV-6) and genes (GSTPi, IB4, and HNF1ß). At the same time, expression of Notch 1 and Notch 2 mRNA were detected during cell differentiation, as well as their downstream target genes such as Hes 1 and Hes 5. Inhibition of the Notch signal pathway by L-685458 resulted in decreased expression of Notch and their downstream genes. In addition, the proportion of cholangiocyte-like cells declined from approximately 90% to approximately 20%. These results suggest that Notch signaling may play a critical role in cholangiocytic development from ES cells.

Temporal and spatial expression of integrins and their extracellular matrix ligands at the maternal-fetal interface in the rhesus monkey during pregnancy.

The integrin and extracellular matrix protein (ECM)-mediated adhesion and invasion of the receptive maternal uterine endometrium by trophoblasts is a critical event in the complex physiological process of pregnancy. Although the process has been largely characterized in mice, the relevant mechanism in primates remains unclear. We investigated the expression patterns and dynamic alterations of integrin subunits (alpha1, alpha5, alpha6, beta1, and beta4) and their ECM ligands, such as laminin (LN), type IV collagen (Col IV), and fibronectin (FN), at the maternal-fetal interface during Gestational Days 15, 25, 50, and 100 and at full term in 20 pregnant rhesus monkeys. Immunohistochemistry and in situ hybridization revealed that a relatively high expression of integrins occurred in trophoblast cells at Gestational Day 15, with the peak level occurring at Day 25. The expression level decreased from Day 50 to term. Along the invasive pathway, expression levels of integrin alpha1, alpha5, and beta1 subunits were gradually elevated from the proximal to distal column, reaching peak level in the trophoblast shell, but were reduced in those invasive extravillous cytotrophoblast (EVCT) cells in contact with the decidua. Integrin alpha1, alpha5, beta1, and beta4 subunits were also highly expressed in decidual stromal cells and moderately expressed in the maternal epithelium and endothelium. Immunoreactive FN, LN, and Col IV were distributed in EVCT and decidual stromal cells and part of the uterine epithelial and endothelial cells. These data suggest that the correlated expression of integrins and their ECM ligands at the maternal-fetal interface might be involved in regulation of cell proliferation and differentiation and the counterbalanced invasion-accelerating and invasion-restraining processes in trophoblast cells during the early stage of pregnancy.