The Effect of Inhibiting the Wingless/Integrated (WNT) Signaling Pathway on the Early Embryonic Disc Cell Culture in Chickens.

The utilization of chicken embryonic-derived pluripotent stem cell (PSC) lines is crucial in various fields, including growth and development, vaccine and protein production, and germplasm resource protection. However, the research foundation for chicken PSCs is relatively weak, and there are still challenges in establishing a stable and efficient PSC culture system. Therefore, this study aims to investigate the effects of the FGF2/ERK and WNT/ß-catenin signaling pathways, as well as different feeder layers, on the derivation and maintenance of chicken embryonic-derived PSCs. The results of this study demonstrate that the use of STO cells as feeder layers, along with the addition of FGF2, IWR-1, and XAV-939 (FIX), allows for the efficient derivation of chicken PSC-like cells. Under the FIX culture conditions, chicken PSCs express key pluripotency genes, such as POUV, SOX2, and NANOG, as well as specific proteins SSEA-1, C-KIT, and SOX2, indicating their pluripotent nature. Additionally, the embryoid body experiment confirms that these PSC-like cells can differentiate into cells of three germ layers in vitro, highlighting their potential for multilineage differentiation. Furthermore, this study reveals that chicken Eyal-Giladi and Kochav stage X blastodermal cells express genes related to the primed state of PSCs, and the FIX culture system established in this research maintains the expression of these genes in vitro. These findings contribute significantly to the understanding and optimization of chicken PSC culture conditions and provide a foundation for further exploration of the biomedical research and biotechnological applications of chicken PSCs.

Clonally derived chicken primordial germ cell lines maintain biological characteristics and proliferative potential in long-term culture.

Chicken primordial germ cells (PGCs) are important cells with significant implications in preserving genetic resources, chicken breeding and production, and basic research on genetics and development. Currently, chicken PGCs can be cultured long-term in vitro to produce single-cell clones. However, systematic exploration of the cellular characteristics of these single-cell clonal lines has yet to be conducted. In this study, single-cell clonal lines were established from male and female PGCs of Rugao Yellow Chicken and Shouguang Black Chicken, respectively, using a micropipette-based method for single-cell isolation and culture. Analysis of glycogen granule staining, mRNA expression of pluripotency marker genes (POUV, SOX2, NANOG), germ cell marker genes (DAZL, CVH), and SSEA-1, EMA-1, SOX2, C-KIT, and CVH protein expression showed positive results, indicating that PGCs maintain normal cellular properties after single-cell cloning. Furthermore, tests on proliferation ability and gene expression levels in PGC single-cell clonal lines showed high expression of the pluripotency-related genes and TERT compared to control PGCs, and PGC single-cell clonal lines demonstrated higher proliferation ability. Finally, green fluorescent protein (GFP)-PGC single-cell clonal lines were established, and it was found that these single-cell clonal lines could still migrate into the gonads of recipients, suggesting their potential for germ-line transmission. This study systematically validated the normal cellular characteristics of PGC single-cell clonal lines, indicating that they could be applied in genetic modification research on chickens.

Effects of growth irradiance on photosynthesis and photorespiration of Phoebe bournei leaves.

Light intensity is a major environmental factor affecting the growth and survival of trees in a forest. The effect of light reduction on photosynthesis and photorespiration of an evergreen broad-leaved tree, Phoebe bournei (Hemsley) Yang was examined with three levels of full light, 50.5% light, and 21.8% light. The results showed that shading led to significant increase in plant height and crown diameter. Light-saturated leaf photosynthetic rate (Amax), maximal carboxylation activity (Vcmax), maximum electron transfer rate (Jmax), stomatal conductance (gs), mesophyll conductance (gm) and chloroplast CO2 concentration (Cc) significantly increased in response to shade. Photorespiratory CO2 release rate (PR) was higher in plants grown under shade conditions than under full light. The relative limitations of gm (lm) was higher than the relative limitations of gs (ls) and the relative limitations of biochemical factors (lb) in leaves of P. bournei grown under full light, whereas lm was lower than ls and lb under shade. Our results suggest that increase of photosynthesis in P. bournei leaves grown under shade is associated with enhanced CO2 diffusion and biochemistry. And we propose that enhancement of the photorespiratory is essential for shade leaves to improve photosynthesis.

Seed mucilage improves seedling emergence of a sand desert shrub.

The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged) were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 mm) and irrigation regimes (low, medium and high, which simulated the precipitation amount and frequency in May, June and July in the natural habitat, respectively). Seedling emergence increased with increasing irrigation. It was highest at 5 mm sand burial depth and ceased at burial depths greater than 20 mm in all irrigation regimes. Mucilage significantly enhanced seedling emergence at 0, 5 and 10 mm burial depths in low irrigation, at 0 and 5 mm burial depths in medium irrigation and at 0 and 10 mm burial depths in high irrigation. Seed mucilage also reduced seedling mortality at the shallow sand burial depths. Moreover, mucilage significantly affected seedling emergence time and quiescence and dormancy percentages. Our findings suggest that seed mucilage plays an ecologically important role in successful seedling establishment of A. sphaerocephala by improving seedling emergence and reducing seedling mortality in stressful habitats of the sandy desert environment.

A wearable respiratory biofeedback system based on body sensor networks.

Technology advantages of body sensor networks (BSN) have shown great deal of promises in medical applications. In this paper we introduced a wearable device for biofeedback application based on the BSN platform we had developed. The biofeedback device we have developed includes the heart rate monitoring belt with conductive fabric and the biofeedback device with respiration belt. A wearable respiratory biofeedback system was preliminarily explored based on the BSN platform. In-situ experiments showed that the BSN platform and the biofeedback device worked as intended.