Studies on Agricultural Scientific and Technical Information Core Metadata Register System

To construct the Agricultural Scientific and Technical Information Core Metadata （ASTICM） standard and its expanding principles, and to develop a register system based on ASTICM, the policy and methods of DC （Dublin Core） and SDBCM （Scientific Database Core Metadata） were studied. The construction of ASTICM has started from the proposed elements of the DCMI （Dublin Core Metadata Initiative）, and has expanded the DC and SDBCM with related expanding principles. ASTICM finally includes 75 metadata elements, five expanded principles, and seven application profile creation methods. According to the requirement analysis of a large number of users of agricultural information, a register system based on ASTICM was developed. The ASTICM standard framework and its register system supported the search, sharing, integration exchange and other applications, effectively.

Efficient generation of transgenic chickens using the spermatogonial stem cells in vivo and ex vivo transfection

The highly efficient novel methods to produce transgenic chickens were established by directly in-jecting the recombinant plasmid containing green fluorescent protein (GFP) gene into the cock's testis termed as testis-medianted gene transfer (TMGT), and transplanting transfected spermatogonial stem cells (TTSSCs). For the TMGT approach,four dosages of pEGFP-N1 DNA/cationic polymer complex were injected intratesticularly. The results showed: (1) 48 h after the injection,the percentages of testis cells expressing GFP were 4.0%, 8.7%, 10.2% and 13.6% in the 50, 100, 150 and 200 μg/mL group, re-spectively. The difference from the four dosage groups was significant (P<0.05). On day 25 after the injection, a dosage-dependent and time-dependent increase in the number of transgenic sperm was observed. The percentages of gene expression reached the summit and became stable from day 70 to 160, being 12.7%, 12.8%, 15.9% and 19.1%, respectively. The difference from the four dosage groups was also significant (P<0.05). (2) 70 d after the injection, strong green fluorescent could be observed in the seminiferous tubules by whole-mount in-situ hybridization. (3) 70 d after the injection, the semen was collected and used to artificially inseminate wild-type females. The blastoderms of F1 and F2 transgenic chicken expressed GFP were 56.2% (254/452) and 53.2% (275/517), respectively. The detec-tion of polymerase chain reaction (PCR) of F1 and F2 transgenic chicken blood genomic DNA showed that 56.5% (3/23) of F1 and 52.9% (9/17) of F2 were positive. Southern blot showed GFP DNA was in-serted in their genomic DNAs. (4) Frozen whole mount tissue sections of F1 and F2 transgenic chicken liver, heart, kidney and muscle showed that the rates of green fluorescent positive were between 50.0% and 66.7%. (5) With the TTSSCs method, SSCs ex vivo transfected with GFP were transplanted into recipient roosters whose endogenic SSCs had been resoluted. The donor SSCs settled and GFP ex-pression became readily detectable in the frozen whole mount tissue sections of recepient testes. Moreover, sperms carrying GFP could be produced normally. The results of artificially inseminating wild-type females with these sperms showed 12.5% (8/64) of offspring embryo expressed GFP and 11.1% (2/18) hatched chicks were tested transgenic. Our data therefore suggest TMGT and TTSSCs are the feasible methods for the generation of transgenic chickens.

Antibiotic growth promoter olaquindox increases pathogen susceptibility in fish by inducing gut microbiota dysbiosis

Low dose antibiotics have been used as growth promoters in livestock and fish. The use of antibiotics has been associated with reduced pathogen infections in livestock. In contrast, antibiotic growth promoter has been suspected of leading to disease outbreaks in aquaculture. However, this phenomenon is circumstantial and has not been confirmed in experimental conditions. In this study,we showed that antibiotic olaquindox increased the susceptibility of zebrafish to A. hydrophila infection. Olaquindox led to profound alterations in the intestinal microbiota of zebrafish, with a drastic bloom of Enterobacter and diminishing of Cetobacterium. Moreover, the innate immune responses of zebrafish were compromised by olaquindox(P<0.05). Transfer of microbiota to GF zebrafish indicated that while the immuo-suppression effect of olaquindox is a combined effect mediated by both OLA-altered micro biota and direct action of the antibiotic(P<0.05), the increased pathogen susceptibility was driven by the OLA-altered microbiota and was not dependent on direct antibiotic effect. Taken together, these data indicate that low level of OLA induced gut microbiota dysbiosis in zebrafish, which led to increased pathogen susceptibility.

Watering techniques and zero-valent iron biochar pH effects on As and Cd concentrations in rice rhizosphere soils,tissues and yield

Zero-valent iron amended biochar(ZVIB)has been proposed as a promising material in immobilizing heavy metals in paddy fields.In this study,the impacts of p H of ZVIB(p H 6.3 and p H 9.7)and watering management techniques(watering amount in the order of CON(control,5/72)>3/72>1-3/72>3/100>1/72,with 5/72,for example,representing irrigation given to 5 cm above soil surface in 72 hr regular interval)on As and Cd bioavailability for rice and its grain yield(Yield BR)were investigated in a pot experiment.Brown rice As(As BR)content was irrelative to the watering treatments,while significantly decreased(>50%)with the addition of both ZVIB materials.The diminutions of brown rice Cd(Cd BR)content as well as the Yield BR were highly dependent on both the soil amendment materials’p H and watering amount.Among all the watering treatments,3/72 treatment(15%less irrigation water than the CON)with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of As BR(50%)and Cd BR contents(19%)as well as for significant increment(12%)of the Yield BR.Although high pH(9.7)ZVIB application could also efficiently decrease As and Cd contents in brown rice,it might risk grain yield lost if appropriate(e.g.3/72 in our study)watering management technique was not chosen.Therefore,ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.