Identification of genes involved in regulating the development of feathered feet in chicken embryo.

The genetic and developmental factors driving the diverse distribution and morphogenesis of feathers and scales on bird feet are yet unclear. Within a single species, Guangxi domestic chickens exhibit dramatic variety in feathered feet, making them an accessible model for research into the molecular basis of variations in skin appendages. In this study, we used H&E staining to observe the morphogenesis of feathered feet, scaled feet and wings skin at different embryonic stages in Longsheng-Feng chickens and Guangxi Partridge chickens. We selected 4 periods (E6, E7, E8, and E12) that play an important role in feather development and performed transcriptome sequencing to screen for candidate genes associated with feathered feet. Through comparison and analysis of transcriptome data, we identified a set of differently expressed genes (DGEs), which were enriched in appendage organ development, hindlimb morphogenesis, activation of transcription factor binding, and binding of sequence-specific DNA in the cis-regulatory region. In addition, we identified some feathered feet-related genes by analyzing the classical signaling pathways that regulate feather development. Finally, we identified candidate genes that regulate feathered feet formation, which include TBX5, PITX1, ZIC1, FGF20, WNT11, WNT7A, WNT16, and SHH. Interestingly, we found that TBX5 was significantly overexpressed in the skin of the feathered feet and had the highest expression at E7 (P < 0.01), whereas PITX1 expression was significantly reduced at E7(P < 0.01). It is hypothesized that TBX5 and PITX1 regulate the development of hair follicles through the Wnt/ß-catenin signaling pathway at E7. Our results provide a theoretical basis for investigating the molecular regulatory mechanisms underlying the formation of chicken feathered feet.

Sulfonylurea and fracture risk in patients with type 2 diabetes mellitus: A meta-analysis.

AIMS: This meta-analysis was conducted to investigate the fracture risk among patients with T2DM treated with sulfonylurea. METHODS: The PubMed and other databases were searched for eligible studies. Both randomized controlled trials and observational studies that compared the fracture risk of sulfonylurea to other hypoglycemic agents were included. Pooled risk ratios and 95% confidence intervals were calculated. Subgroup analysis and meta-regression analyses were conducted to explore the source of heterogeneity. RESULTS: A total of 11 studies involving 255,644 individuals were included in our meta-analysis. In comparing sulfonylurea users with patients who had not taken sulfonylurea, the pooled risk ratio for developing fracture was 1.14 (95% confifidence interval, 1.08-1.19). In subgroup analyses, the pooled risk ratio of bone fracture in patients receiving sulfonylurea versus thiazolidinedione, metformin and insulin was 0.90 (95% CI, 0.76-1.06), 1.25 (95% CI, 1.18-1.32) and 0.81 (95% CI, 0.74-0.89) respectively. Meta regression showed that age and gender were not related to the effect of sulfonylurea on fracture. CONCLUSIONS: Sulfonylurea use was associated with 14% increase in the risk of developing fracture in T2DM. The risk of fracture caused by sulfonylurea was similar to thiazolidinedione, higher than metformin and lower than insulin.