Enhanced seed oil production in canola by conditional expression of Brassica napus LEAFY COTYLEDON1 and LEC1-LIKE in developing seeds

The seed oil content in oilseed crops is a major selection trait to breeders. In Arabidopsis (Arabidopsis thaliana), LEAFY COTYLEDON1 (LEC1) and LEC1-LIKE (L1L) are key regulators of fatty acid biosynthesis. Overexpression of AtLEC1 and its orthologs in canola (Brassica napus), BnLEC1 and BnL1L, causes an increased fatty acid level in transgenic Arabidopsis plants, which, however, also show severe developmental abnormalities. Here, we use truncated napin A promoters, which retain the seed-specific expression pattern but with a reduced expression level, to drive the expression of BnLEC1 and BnL1L in transgenic canola. Conditional expression of BnLEC1 and BnL1L increases the seed oil content by 2% to 20% and has no detrimental effects on major agronomic traits. In the transgenic canola, expression of a subset of genes involved in fatty acid biosynthesis and glycolysis is up-regulated in developing seeds. Moreover, the BnLEC1 transgene enhances the expression of several genes involved in Suc synthesis and transport in developing seeds and the silique wall. Consistently, the accumulation of Suc and Fru is increased in developing seeds of the transgenic rapeseed, suggesting the increased carbon flux to fatty acid biosynthesis. These results demonstrate that BnLEC1 and BnL1L are reliable targets for genetic improvement of rapeseed in seed oil production.     

分子标记技术及其在水稻基因定位上的应用

分子标记作为一种新兴的遗传标记手段,因其特有的优势而得到广泛的应用,带动了许多领域的快速发展.本文主要对分子标记的一般特点,基于全基因序列、简单重复序列、已知的特定序列、反转录转座子、单核苷酸的分子标记的类型及各类型代表性技术的基本原理和各自的优缺点进行详尽的综述,并进一步介绍了近年来分子标记在水稻基因定位上的相关应用,如水稻高产、优质、抗逆和抗病等重要农艺性状基因的分离克隆.最后还对分子标记技术在遗传图谱构建、基因定位和分子标记辅助育种等方面的应用前景予以展望,以期该技术能发挥更大的作用.     

Rapamycin ameliorates kidney fibrosis by inhibiting the activation of mTOR signaling in interstitial macrophages and myofibroblasts

Interstitial fibrosis is an inevitable outcome of all kinds of progressive chronic kidney disease (CKD). Emerging data indicate that rapamycin can ameliorate kidney fibrosis by reducing the interstitial infiltrates and accumulation of extra cellular matrix (ECM). However, the cellular mechanism that regulates those changes has not been well understood yet. In this study, we revealed the persistent activation of mammalian target of rapamycin (mTOR) signaling in the interstitial macrophages and myofibroblasts, but rarely in injured proximal epithelial cells, CD4+ T cells, neutrophils, or endothelial cells, during the development of kidney fibrosis. Administration of rapamycin to unilateral ureteral obstruction (UUO) mice significantly suppressed the immunoreactivity of mTOR signaling, which decreased the inflammatory responses and ECM accumulation in the obstructed kidneys. Isolated macrophages from rapamycin-treated obstructed kidneys presented less inflammatory activity than vehicle groups. In vitro study confirmed that rapamycin significantly inhibited the fibrogenic activation of cultured fibroblasts (NIH3T3 cells), which was induced by the stimulation of TGF-β(1). Further experiment revealed that rapamycin did not directly inhibit the fibrogenesis of HK2 cells with aristolochic acid treatment. Our findings clarified that rapamycin can ameliorate kidney fibrosis by blocking the mTOR signaling in interstitial macrophages and myofibroblasts.     

Cordycepin inhibits albumin-induced epithelial-mesenchymal transition of renal tubular epithelial cells by reducing reactive oxygen species production

Albumin induced epithelial-mesenchymal transition (EMT) of renal tubular cells through reactive oxygen species (ROS) pathway plays an important role in tubulointerstitial fibrosis. Cordycepin (3 -deoxyadenosine), a potential antioxidant, was demonstrated to have various pharmacological effects and could inhibit EMT of some cells. However, the role of cordycepin on albumin-induced EMT in renal tubular cells (HK2) is unclear. In this study, we investigated the effect of cordycepin on albumin-induced EMT of HK2 cells and its mechanisms. HK-2 cells were exposed to bovine serum albumin with or without pretreatment with cordycepin. Results showed that albumin significantly induced EMT formation of HK-2 which associated with NADPH oxidase activation and intracellular ROS overproduction through increased Rac1 activity and expression of NOX4, p22phox and p47phox, while these effects were abolished in that pretreated with cordycepin. In conclusion, cordycepin could ameliorate albumin-induced EMT of HK2 cells by decreasing NADPH oxidase activity and inhibiting ROS production.     

周口店第一地点西剖面2009-2010年发掘报告

周口店第一地点再次发掘的主要目的在于提升遗址西剖面的保护状态与水平,同时也为东亚直立人演化方面某些焦点问题的研究与解决提供机遇与可能。2009-2010年,在西剖面最顶部堆积(即第三层)的野外发掘中共计出土大中型动物化石材料约800件。埋藏学研究表明,西剖面第三层中葛氏斑鹿(Cervus(Sika)grayi)等动物属种的骨骼富集并非古人类生存行为的结果;石制品以及古人类化石材料的缺失也在一定程度上印证了这一结论。结合发掘过程中揭露出来的一系列洞穴坍塌事件的证据,我们初步认为,至少在第三层堆积形成时期,第一地点西剖面位置处的洞穴形态并不适合于古人类的栖居活动;葛氏斑鹿等骨骼材料则是当时在遗址附近活动的各种动物因意外因素陷落于其中而得以聚集的。     

非损伤采样提取DNA技术在猫科动物调查中的应用

<正>猫科动物广泛分布于世界各地(Johnson et al.,2006),全球现存37种猫科动物,其中25种已被国际自然保护联盟(IUCN)列为濒危和易危,86%以上的种群数量处于下降或未知状态(IUCN Red List,2011)。我国有13种猫科动物,占世界种类的35%(王应祥,2003),其中属于国家一级保护的有4种,二级保护的有8种,然而,对这些珍稀物种的生态学研究并不充分(高耀亭,     

Identification and Expression Pattern Analysis of Bacterial Blight Resistance Genes in Oryza officinalis Wall ex Watt Under Xanthomonas oryzae Pv. oryzae Stress

Plant Molecular Biology Reporter - Bacterial blight (BB) caused by Xanthomonas oryzae Pv. oryzae (Xoo) is one of the most serious diseases of rice worldwide. Oryza officinalis Wall ex Watt,...     

壳聚糖在组织工程中应用的研究进展

壳聚糖是由2-氨基-2-脱氧-β-D-葡萄糖通过β-1,4糖苷键聚合的一种天然聚阳离子生物多糖,结构类似硫酸软骨素、透明质酸等物质,体内移植或注射无炎症和变态反应,在动物体内可被降解为氨基葡萄糖,参与代谢,表现出良好的生物相容性和生物可降解性,是细胞培养的良好的脚手架,因而在组织工程中显示出较为广泛的应用前景。综述了壳聚糖在皮肤修复、神经修复、骨及软骨修复、肝脏修复等方面的研究进展 。     

石制品废片尺寸分布的实验研究:以泥河湾盆地大田洼区域燧石原料为例

石制品废片尺寸分布区间是旧石器时代遗址形成过程研究中常采用的一项衡量指标。20世纪70~80年代,美国印第安纳大学的学者Kathy Schick与Nicholas Toth针对东非肯尼亚Koobi Fora地区旧石器时代早期遗址中常见的石料与石器生产技术,开展了大量的废片尺寸分布实验研究,所产生的数据在国际学术界产生重要影响并得到广泛应用。本文在参考Kathy Schick等实验的基础上,对泥河湾盆地大田洼区域旧石器时代遗址中常见的周家山、东谷坨两类燧石原料进行了废片尺寸分布实验研究,以建立该区域燧石原料的废片尺寸分布模式,为该区域遗址形成过程的研究提供直接的参考数据。实验共计25组,获得废片标本10070件。结果显示,两类燧石原料的废片尺寸分布模式基本一致,整体呈随尺寸增加废片数量比例逐渐降低的单一递减分布特征,其中0.5~1cm的比例最高,1~2cm次之,其他尺寸的比例逐渐降低。本次实验验证了Kathy Schick等获得的实验数据中小于2cm废片占绝对优势的结论,但对小于1cm的废片产品比例存在偏差,原料物理性质可能是实验结果产生偏差的原因。本文实验数据更适合作为对比数据评估泥河湾盆地早、中更新世遗址中石制品组合的完整程度。