The Effects of Di-(2-ethylhexyl)-phthalate Exposure on Fertilization and Embryonic Development In Vitro and Testicular Genomic Mutation In Vivo

The present study was undertaken to determine the reproductive hazards of Di-(2-ethylhexyl)-phthalate (DEHP) on mouse spermatozoa and embryos in vitro and genomic changes in vivo. Direct low-level DEHP exposure (1 μg/ml) on spermatozoa and embryos was investigated by in vitro fertilization (IVF) process, culture of preimplanted embryos in DEHP-supplemented medium and embryo transfer to achieve full term development. Big Blue® transgenic mouse model was employed to evaluate the mutagenesis of testicular genome with in vivo exposure concentration of DEHP (500 mg/kg/day). Generally, DEHP-treated spermatozoa (1 μg/ml, 30 min) presented reduced fertilization ability (P<0.05) and the resultant embryos had decreased developmental potential compared to DMSO controls (P<0.05). Meanwhile, the transferred 2-cell stage embryos derived from treated spermatozoa also exhibited decreased birth rate than that of control (P<0.05). When fertilized oocytes or 2-cell stage embryos were recovered by in vivo fertilization (without treatment) and then exposed to DEHP, the subsequent development proceed to blastocysts was different, fertilized oocytes were significantly affected (P<0.05) whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05). Testes of the Big Blue® transgenic mice treated with DEHP for 4 weeks indicated an approximately 3-fold increase in genomic DNA mutation frequency compared with controls (P<0.05). These findings unveiled the hazardous effects of direct low-level exposure of DEHP on spermatozoa''s fertilization ability as well as embryonic development, and proved that in vivo DEHP exposure posed mutagenic risks in the reproductive organ – at least in testes, are of great concern to human male reproductive health.     

Efficient Gene Transfer into Neonatal Mouse Brain Using Electroporation

In vivo electroporation works as an effective method to transfer exogenous genes into postnatal rodent forebrain. Nevertheless, two deficiencies were found in the reported methods. First, surgical operation brings unnecessary trauma to newborn pups. Second, the procedure was complicated and the transfection efficiency was relatively low. Here we improved the previous electroporation method and make it more simple and efficient. The pulse voltage was decreased to 90 v. DNA injection into one pup's forebrain could be completed within 30 s without any surgical operation. More than 94% of injected neonates survived. Almost 100% of the survivors expressed the introduced gene and the expression persists as long as 20 days after injection. Thus, this method offers a powerful new way for gene function study in postnatal neurogenesis and neural development.     

Allopolyploidization-accommodated genomic sequence changes in triticale

Background: Allopolyploidization is one of the major evolutionary modesof plant speciation. Recent interest in studying allopolyploidshas provided significant novel insights into the mechanismsof allopolyploid formation. Compelling evidence indicates thatgenetic and/or epigenetic changes have played significant rolesin shaping allopolyploids, but rates and modes of the changescan be very different among various species. Triticale (x Triticosecale)is an artificial species that has been used to study the evolutionarycourse of complex allopolyploids due to its recent origin andavailability of a highly diversified germplasm pool. Scope: This review summarizes recent genomics studies implemented inhexaploid and octoploid triticales and discusses the mechanismsof the changes and compares the major differences between genomicchanges in triticale and other allopolyploid species. Conclusions: Molecular studies have indicated extensive non-additive sequencechanges or modifications in triticale, and the degree of variationappears to be higher than in other allopolyploid species. Thedata indicate that at least some sequence changes are non-random,and appear to be a function of genome relations, ploidy levelsand sequence types. Specifically, the rye parental genome demonstrateda higher level of changes than the wheat genome. The frequencyof lost parental bands was much higher than the frequency ofgained novel bands, suggesting that sequence modification and/orelimination might be a major force causing genome variationin triticale. It was also shown that 68 % of the total changesoccurred immediately following wide hybridization, but beforechromosome doubling. Genome evolution following chromosome doublingoccurred more slowly at a very low rate and the changes weremainly observed in the first five or so generations. The datasuggest that cytoplasm and relationships between parental genomesare key factors in determining the direction, amount, timingand rate of genomic sequence variation that occurred duringinter-generic allopolyploidization in this system.     

Thymoquinone induces cytotoxicity and reprogramming of EMT in gastric cancer cells by targeting PI3K/Akt/mTOR pathway

Gastric cancer is one of the lethal causes of cancer-related deaths worldwide. The incidence and mortality rates of this disease is comparatively higher in China. In the current study, we evaluated the anticancer effects of Thymoquinone (TQ) against gastric cancer cells (MGC80-3 and SGC-7901) and normal noncancerous GES-1 cells and attempted to investigate the underlying mechanism. Our results indicated that TQ exhibited significant growth inhibitory effects on gastric cancer cells (MGC80-3 and SGC-7901). However, lower cytotoxicity was observed against normal GES-1 cells. Moreover, TQ could inhibit the colony formation potential of MGC80-3 and SGC-7901 cells in a dose-dependent manner. TQ also inhibited cell migration ability of the gastric cancer cells and down-regulated the expression of the mesenchymal genes such as N-cadherin, Vimentin, and TWIST. However, the epithelial markers such as E-cadherin and cytokeratin-19 were distinctly up-regulated in TQ-treated gastric cancer cells. Since PI3K/Akt/ mTOR plays an important role in progression and tumorigenesis, we also investigated the effect of TQ on PI3K/Akt/mTOR signalling pathway in gastric cancer cells. It was observed that TQ down-regulated the expression of some of the key proteins of this pathway. Taken together, we conclude that TQ may prove lead molecule for the treatment of gastric cancer.     

Historical introduction,geographical distribution,and biological characteristics of alien plants in China

Using the published literature and records, this study investigated the historical introduction, geographical distribution, and biological characteristics of 404 alien plants in 32 provinces (including municipalities) in China. The results showed that three fifths of the alien plants was introduced for intentional purposes, and the introduction of alien plants increased with time from 139 BC to the current time, especially during historical events that played an important part in the process of introduction. The geographical distribution of alien plant species tended to decrease from the south and the east to the north and the west. Annual average precipitation (Y = 7.51X + 7.05, R² = 0.67) and temperature (Y = 0.07X + 41.54, R² = 0.67) had a linear relationship with alien plant introduction throughout China. Furthermore, population density and economic conditions also affected and promoted plant invasions in China. The life forms were well adapted to regional precipitation and temperature, but different life forms of alien plants were not consistent with the distribution tendency based on the quantity of alien plants. There was a higher percentage of annual and biennial plants in the northern provinces (e.g. 66.7 and 15.7% in Inner Mongolia), whereas there were more perennial and woody plant species in the southern provinces (e.g. 37.0 and 21.2% in Hainan). Family characteristics could not accurately predict plant invasions; however, predictions based on genera were acceptable. In addition, the origin of alien plants can also predict the distribution and potential risk of invasions. Thus, our study investigated the factors affecting plant invasions in order to provide information on the prevention and control of alien plants.     

人肾素转基因小鼠的建立

为研究人肾素基因在体内的功能和建立其药物干预实验的动物模型,采用显微注射法,将纯化的人肾素基因导入小鼠受精卵,再培育成转基因小鼠.通过DIG DNA印迹和PCR分析,进行转基因整合检测.在出生的13只子代鼠中,得到一只转基因阳性鼠.整合率为7.7%,有效率0.3%,转基因已稳定传代.RT-PCR显示转基因阳性鼠的肾、心和肺组织中有肾素基因表达,而在肝脏与骨骼肌中则未检测到.阳性鼠血浆肾素活性较对照鼠明显升高,而肾与心脏组织的肾素活性则无明显变化.人肾素转基因小鼠可用于研究循环或组织的RAS中肾素基因的功能及有关其药物抑制实验.     

转铜伴侣的功能与结构特性

铜是生物体不可缺少的一种元素,在细胞内把铜转运到含铜的蛋白质是细胞正常代谢的基本要求,转铜伴铝在体内执行重要的生理功能,它们不但保护细胞免受游离铜离子的有害作用。而且也确保铜被运输到其特异的靶蛋白。作者综述了转铜伴铝的功能、结构特性,以及可能的金属转移机制。     

蓝尾石龙子孵化期卵内物质和能量的利用

研究了安徽滁州蓝尾石龙子卵在温、湿度分别为 3 0℃、-1 2kPa的孵化条件下 ,胚胎对卵内物质和能量的利用。本研究蓝尾石龙子卵孵化期为 2 1 1d ,卵孵化时从基质中吸水导致重量增加。卵孵化过程中 ,干重、非极性脂肪和能量转化到孵出幼体的比率分别为 5 7 1 %、3 8 8%和 5 2 3 %。新生卵卵壳中5 0 %的灰分、5 9%的钙转移至孵出幼体中 ,胚胎发育所需要的无机物来自卵黄和卵壳。