The effect of Chinese wild blueberry fractions on the growth and membrane integrity of various foodborne pathogens.

The objective of this study was to evaluate the antibacterial effect of Chinese wild blueberry extract and its fractions against Listeria monocytogenes, Staphylococcus aureus, Salmonella Enteritidis, and Vibrio parahaemolyticus. Chinese wild blueberry (Vaccinium uliginosum) crude extract (BBE) was obtained using methanol extraction, and sugars plus organic acids (F1), phenolics fraction (F2), and anthocyanins plus proanthocyanidins (F3) fractions were separated using C-18 Sep-Pak columns. The minimal inhibitory concentration and minimal bactericidal concentration of each fractional component were determined using a two-fold-serial dilution method. Nucleic acid leakage (OD260 nm ) and protein release (Bradford protein assay) were determined by spectrophotometry, to evaluate the permeability of the cell membrane. F3 was found to exhibit the greatest antimicrobial activity against the four tested strains, followed by F2, F1, and BBE. V. parahaemolyticus was the most sensitive to the all fractions, followed by S. Enteritidis, L. monocytogenes, and S. aureus. Survival curve analysis showed that the number of bacteria decreased from six log colony-forming units (CFU) to less than 10 CFU after bacteria were treated with fractions for 12 hr, which demonstrated the bactericidal effect of blueberry fractions. Furthermore, when the pathogens were treated with fractions for 2 hr, the OD260 nm and OD595 nm values increased significantly (P < 0.01), which indicated the significant release of nucleic acid and protein. The results from this study indicated that blueberry fractions, especially F3, inhibited the growth of foodborne pathogens by damaging their cell membrane, and may be developed as a natural preservative to prevent and control foodborne pathogens. PRACTICAL APPLICATION: A blueberry crude extract and its sugars plus organic acids, phenolics, and anthocyanins plus proanthocyanidins fractions, inhibited the growth of foodborne pathogens by destroying their cell membrane. Therefore, Chinese wild blueberries have potential as a natural preservative to prevent and control foodborne pathogens.

Expression analysis of DIO2, EYA3, KISS1 and GPR54 genes in year-round estrous and seasonally estrous rams.

The expression characteristics of the hypothalamic-pituitary-gonadal (HPG) axis-related candidate genes, DIO2, EYA3, KISS1 and GPR54, were analyzed in year-round estrous rams (small-tail Han sheep, STH) and seasonally estrous rams (Sunite sheep, SNT) using qPCR. The results were as follows: DIO2 was mainly expressed in pituitary, and KISS1 was specifically expressed in hypothalamus in the two groups. However, EYA3 and GPR54 were widely expressed in the cerebrum, cerebellum, hypothalamus, pituitary, testis, epididymis, vas deferens and adrenal gland tissues in both breeds, with significant differences in the cerebellum, hypothalamus, pituitary, testis and vas deferens tissues. We speculated that DIO2 and KISS1 may have positive roles in different regions in ram year-round estrus. Moreover, the expression patterns of EYA3 and GPR54 suggested that they may regulate the estrous mode of ram via testis and vas deferens. This is the first study to systematically analyze the expression patterns of HPG axis-related genes in rams.

[Differential expression analysis of proteins in neutrophils between clinical mastitis and healthy dairy cows].

Neutrophils provide the first line of defense against invading pathogens and have been reported to play a key role in bovine mammary immune. To examine the differential expression of proteins in neutrophils between clinical mastitis and healthy dairy cows, a 2-dimensional electrophoresis gel map with high repeatability was constructed for bovine neutrophils. From this map, seven differentially expressed proteins were identified by MALDI-TOF MS which are believed to be involved in pathways such as cell metabolism, oxidative stress, and inflammatory reaction. The differentially expressed proteins identified in this study may provide the basis for bovine mastitis resistance breeding research.

[Animal gene pyramiding in cross populations].

Gene pyramiding aims at producing individuals with one superior economic trait according to the optimal breeding scheme involving selection of favorable target alleles or linked markers after crossing basal populations and pyramiding them into a single individual. In consideration of animal traditional cross program along with the features of animal segregating population, four types of cross programs and two types of selection strategies for gene pyramiding are performed from practice perspective of view, two population cross for pyramiding two genes (denoted II), three populations cascading cross for pyramiding three genes (denoted III), four population symmetrical (denoted IV-S) and cascading cross for pyramiding four genes (denoted IV-C), and various schemes (denoted cross program-A-E) were designed for each cross program with different levels of initial favorable allele frequencies, basal population sizes, and trait heritabilities. The process of gene pyramiding for various schemes were simulated and compared based on the population hamming distance, average superior genotype frequencies, and average phenotypic values. By simulation, the results showed that larger base population size and higher initial favorite allele frequency resulted in higher efficiency of gene pyramiding. The order of parent crossing was shown to be the most important factor in cascading cross, but had no significant influence on the symmetric cross. The results also showed that genotypic selection strategy was superior to phenotypic selection in accelerating gene pyramiding. The method and corresponding software would be used to compare different cross schemes and selection strategies. Moreover, our study would help to build the optimal gene pyramiding simulation platform.

[Inhibitory effect of toll-like receptor 7 agonist on K562 cells].

The aim of this study was to investigate the inhibitory effect of Toll-like receptor 7 (TLR7) agonist gardiquimod on K562 cells. Human γδT cells from peripheral blood cells were amplified by isopentenyl pyrophosphate. The proliferation capacity of γδT cells and K562 cells were measured with MTT assay after treatment with different concentrations of gardiquimod. Cytotoxicity of γδT cells on K562 cells was detected by CCK-8 kit, and the intracellular expression of TLR7, cell cycle and apoptosis of K562 cells before and after treatment with gardiquimod were measured by flow cytometry. The results demonstrated that gardiquimod could significantly stimulate the proliferation of γδT cells, and inhibit proliferation of K562 cells under the concentration of 11.0 µg/ml for 48 h. The expression of TLR7 increased after treatment with gardiquimod. No apoptosis was observed, but there were significant changes in cell cycle, moreover the K562 cells treated with gardiquimod were more killed by γδT cells. It is concluded that the gardiquimod can inhibit the proliferation of K562 cells and enhance their sensitivity to killing activity of human γδT cells.

[Cloning and characterization of CAST transcript 2 and 4 in sheep].

As an endogenous inhibitor of the calpain system activated by Ca2+, calpastatin (CAST) plays a regulatory role in muscle proteolysis. Based on the bovine mRNA sequences, part of cDNA fragments of sheep CAST transcript 2 and 4 were obtained by RT-PCR. Bioinformatic analysis showed that sheep CAST transcript 2 was 4 358 bp in length with an open reading frame (ORF) 2 361 bp long and encoded 786 amino acids, while sheep CAST transcript 4 was 1 467 bp in length with 1 317 bp ORF encoding 438 amino acids. It was predicted that CAST type II contained four conserved domains and CAST type IV contained three conserved domains, and their secondary structures were rich in both hydrophobic regions and helical regions, with certain conserved phosphorylation sites and phosphorylation sites of protein kinase C (PKC). RT-PCR was conducted to analyze the expression patterns of CAST transcript 2 and transcript 4. CAST transcript 2 was ex-pressed in ten tissues detected while CAST transcript 4 only in testis.

[Influence of infusion of Duroc blood on characteristics of chromosomes in Gansu black pig].

The variation of chromosomes of Gansu Black pig was caused by infusion of Duroc blood. The chromosome length ratios of No.1,6,7,13 chromosomes in the line I of Gansu Black pig were higher than those in the line II. It showed that the homogeneity in line I was higher than in line II. The number of Ag-staining nucleolus organizers (Ag-NOR) was between 1-4 in the line I and II, the average No. of Ag-NOR was different obviously between the line I and the line II. This indicated that the activity of translation in rRNA in the line I was different in the line II.