Study on relationship between pollen exine ornamentation pattern and germplasm evolution in flowering crabapple.

Pollen ornamentation patterns are important in the study of plant genetic evolution and systematic taxonomy. However, they are normally difficult to quantify. Based on observations of pollen exine ornamentation characteristics of 128 flowering crabapple germplasms (44 natural species and 84 varieties), three qualitative variables with binary properties (Xi: regularity of pollen exine ornamentation; Yi: scope of ornamentation arrangement regularity; Zi: ornamentation arrangement patterns) were extracted to establish a binary three-dimensional data matrix (Xi Yi Zi) and the matrix data were converted to decimal data through weight assignment, which facilitated the unification of qualitative analysis and quantitative analysis. The result indicates that from species population to variety population and from parent population to variety population, the exine ornamentation of all three dimensions present the evolutionary trend of regular → irregular, wholly regular → partially regular, and single pattern → multiple patterns. Regarding the evolutionary degree, the regularity of ornamentation was significantly lower in both the variety population and progeny population, with a degree of decrease 0.82-1.27 times that of the regularity range of R-type ornamentation. In addition, the evolutionary degree significantly increased along Xi → Yi → Zi. The result also has certain reference values for defining the taxonomic status of Malus species.

Establishment of a pancreatic ß cell proliferation model in vitro and a platform for diabetes drug screening.

Diabetes, a disease resulting from loss of functional ß cells, is globally an increasingly important condition. Based on the islet-differentiation ability of ductal epithelial cells and stimulating ß cell proliferation ability of the Reg Iα gene, we aimed to establish an in vitro pancreatic ß cell proliferation model for screening therapeutic drugs of diabetes in the future. Pancreatic ductal epithelial cells were isolated from male Wistar rats, and induced to differentiate into pancreatic ß cells. Immunofluorescence staining assay, western blot, RT-PCR analysis, and dithizone staining were used to characterize the cells. Rat Reg Iα protein was transiently expressed in vitro by transfection of HEK 293 cells with the PCMV6-entry-REG Ia plasmid, and expression was verified by RT-PCR analysis, proliferation assay, and apoptosis assay. The pancreatic ß cell proliferation model was further validated by a proliferation assay using differentiated pancreatic ß cells treated with transfection supernatant. Finally, we have successfully established an in vitro pancreatic ß cells proliferation model using transiently expressed rat Reg Iα protein and differentiated pancreatic ß cells from pancreatic ductal epithelial cells. This model could be used as a platform to screen new drugs for islet neogenesis to cure diabetes, especially Chinese herbal drugs in the future.