Subchronic Toxicity of GmDREB3 Gene Modified Wheat in the Third Generation Wistar Rats.

The aim of the current study was to evaluate the subchronic toxicity of GmDREB3 gene modified wheat in the third generation rats. SPF Wistar rats were fed with transgenic wheat diet (Gm), parental wheat diet (Jimai22) and AIN-93 rodent diet (Control), respectively, for two generations, to produce the third generation rats which were used for this study. The selected fresh weaned offspring rats (20/sex/group) were given the same diet as their parents for 13 weeks. No toxicity-related changes were observed in rats fed with Gm diet in the following respects: clinical signs, body weights, body weight gains, food consumption, food utilization rate, urinalysis, hematology, serum biochemistry and histopathology. The results from the present study demonstrated that 13 weeks consumption of Gm wheat did not cause any adverse effects in the third generation rats when compared with the corresponding Jimai22 wheat.

Biological evaluation of a novel copper-containing composite for contraception.

OBJECTIVE: To investigate the biocompatibility of a novel copper-containing composite to provide preclinical data for clinical application of intrauterine device (IUD) or intra-vas device (IVD). DESIGN: Prospective experimental study. SETTING: Good laboratory practices laboratories. ANIMALS: Twenty healthy adult mice (SPF grade Kunming white mice, animal code SCXK 2003-0005). INTERVENTION(S): Cytotoxicity tests in vitro were conducted to evaluate the influence of the materials on the morphology, growth, and proliferation of cultured L929 mouse fibroblasts. Acute systemic toxicity tests were conducted to investigate the acute systemic toxic reaction with mice, and then the materials were implanted into the spinal muscle of rabbits (n = 15). The rabbits were sacrificed for pathologic examination at 1, 4, and 12 weeks after surgery. MAIN OUTCOME MEASURE(S): Evaluation of cytotoxicity by MTT assay, cytotoxicity test by direct contact assay, acute systemic toxicity test, and material implantation test. RESULT(S): The cytotoxicity grade of the copper-containing composite was 0-1, suggesting that the material was free of cytotoxicity; no acute systemic toxicity was found in any mice; mild inflammatory reaction was observed in the surrounding tissues of the implanted material in the early implantation stage, which was similar to that of the sham-operated sides. Twelve weeks after implantation, the inflammatory reaction was completely disappeared in the implanted tissue, similarly to the sham-operated sides. The fibrosis membrane surrounding the material became stable gradually over time. CONCLUSION: The copper-containing composite has excellent biocompatibility, which is feasible and safe for the clinical application as a novel contraceptive material.

[Analysis of methylation-sensitive amplified polymorphism in wheat genome under the wheat leaf rust stress].

Intrinsic DNA methylation pattern is an integral component of the epigenetic network in many eukaryotes. DNA methylation plays an important role in regulating gene expression in eukaryotes. Biological stress in plant provides an inherent epigenetic driving force of evolution. Study of DNA methylation patterns arising from biological stress will help us fully understand the epigenetic regulation of gene expression and DNA methylation of biological functions. The wheat near-isogenic lines TcLr19 and TcLr41 were resistant to races THTT and TKTJ, respectively, and Thatcher is compatible in the interaction with Puccinia triticina THTT and TKTJ, respectively. By means of methylation-sensitive amplified polymorphism (MSAP) analysis, the patterns of cytosine methylation in TcLr19, TcLr41, and Thatcher inoculated with P. triticina THTT and TKTJ were compared with those of the untreated samples. All the DNA fragments, each representing a recognition site cleaved by each or both of isoschizomers, were amplified using 60 pairs of selective primers. The results indicated that there was no significant difference between the challenged and unchallenged plants at DNA methylation level. However, epigenetic difference between the near-isogenic line for wheat leaf rust resistance gene Lr41 and Thatcher was present.