天然橡胶(Natural rubber)是一种生物高分子聚合物,由于具有独特的理化性质而成为重要的工业原料及不可替代的战略物资。巴西橡胶树(Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg.)是目前商业化天然橡胶的唯一来源,主要生长在东南亚热带及亚热带地区的种植园中。然而,目前巴西橡胶树的产量难以满足急剧增长的全球工业对天然橡胶的迫切需求。以石油为加工原料的合成橡胶(Synthetic rubber)部分补充天然橡胶产量的不足,但其工业性能无法比拟天然橡胶。因此,亟需开发具有更广泛环境适应性的天然橡胶新作物。本文综述了园艺植物-橡胶草(Taraxacum kok-saghyz Rodin)和莴苣(Lactuca L. species),木本植物-银胶菊(Parthenium argentatum A. Gray)和杜仲(Eucommia ulmoides Oliv.)以及其它有生产天然橡胶潜力的植物的研究进展。本综述以基因组学、转录组学、蛋白质组学和代谢组学等多维组学研究,以及天然橡胶生物合成分子机制为重点,讨论了基于现代生物技术的多维整合策略在解析天然橡胶生物合成机制方面的广阔前景,为加速天然橡胶新作物的培育提供借鉴。
Marek’s disease (MD), a highly cell-associated and contagious disease of chickens caused by Marek’s disease virus (MDV) can result in neural lesions, immunosuppression and neoplasia in chicken. The Meq gene is an important oncogene in the MDV genome, and it is expressed highly in MD tumor tissues and MD T-lymphoblastoid cell lines. An experiment was conducted to elucidate the role of Meq in MD tumor transformation. RNA interference technology was used to block its expression, and then analyzed the biological effects of Meq knockdown on the MD tumor cell line MSB1. A small interfering RNA with an interference efficiency of 70% (P<0.01) was transfected into MSB1 cells to knock down the expression of Meq gene. The cell proliferation, cycle and apoptosis were detected post-Meq knockdown. The results showed that MSB1 cell proliferation was downregulated remarkably at 48 h (P<0.01), 60 h (P<0.05) and 72 h (P<0.01) post-Meq knockdown. The cell cycle was unaffected (P>0.05). B-cell lymphoma 2 gene (BCL2) was anti-apoptotic and caspase-6 was the effector in the apoptosis pathway. The activity of caspase-6 was upregulated (P<0.05) significantly and BCL2 gene expression was downregulated (P<0.05) significantly post-Meq knockdown, suggesting cell apoptosis might be induced. MSB1 cell migration did not exhibit any obvious change (P>0.05) post-Meq knockdown, but the expression of two genes (matrix metalloproteinase 2 (MMP2) and MMP9) that are correlated closely to cell invasion was downregulated (P<0.05) remarkably post-Meq knockdown. The Meq knockdown might affect the main features of tumorous cells, including proliferation, apoptosis, and invasion, suggesting that the Meq gene might play a crucial role in interfering with lymphomatous cell transformation.