海洋富油微拟球藻Nannochloropsis gaditana CCAP849/5的转化及外源基因整合方式

微拟球藻Nannochloropsis被认为是具有作为生物柴油原料开发潜力的微藻。为了能够实现工业化生产,有效地利用基因工程或遗传操作手段改造微藻,提高产量,建立稳定有效的遗传转移方法十分必要。本研究以微拟球藻本源β-tublin基因启动子和三角褐指藻Phaeodactylum tricornutm fcpA终止子驱动和终止来源于细菌的sh ble抗性选择基因,构建了一个转化载体pHB4857。将pHB4857以电转移的方法转化海洋富油微拟球藻Nannochloropsis gaditana CCAP849/5。结果显示,转化子可以在3μg·mL-1 zeocin的抗性培养基中生长,PCR检测sh ble基因为100%插入率,转化效率为1.25×10-6。DNA印迹杂交结果表明,外源基因是以随机整合的方式一个或多个拷贝插入到宿主核基因组中的,大多数转化子中的外源基因的整合是完整的。转化子在抗性培养基中每10天传一代,连续传代7个月以上,未检测到抗性基因丢失现象,外源抗性基因可以在宿主细胞中稳定存在。     

Vitreoscilla hemoglobin gene (vgb) improves lutein production in Chlorella vulgaris

Vitreoscilla hemoglobin is an oxygen-binding protein that promotes oxygen delivery and reduces oxygen consumption under low oxygen conditions to increase the efficiency of cell respiration and metabolism. In this study, we introduced a Vitreoscilla hemoglobin gene （vgb） into Chlorella vulgaris by Agrobacterium tumefaciens-mediated transformation （ATMT）. PCR analysis confirmed that the vgb gene was successfully integrated into the Chlorella vulgaris genome. Analysis of biomass obtained in shake flasks revealed transformant biomass concentrations as high as 3.28 g/L, which was 38.81% higher than that of the wild-type strain. Lutein content of transformants also increased slightly. Further experiments recovered a maximum lutein yield of 2.91 mg/L from the transformants, which was 36.77% higher than that of the wild-type strain. The above results suggest that integrated expression of the vgb gene may improve cell growth and lutein yield in Chlorella vulgaris, with applications to lutein production from Chlorella during fermentation.     

Cloning and expression patterns of two Smad genes during embryonic development and shell formation of the Pacific oyster Crassostrea gigas

Increasing evidence indicates that transforming growth factor β(TGF-P) signaling pathways play many important roles in the early development of mollusks.However,limited information is known concerning their detailed mechanisms.Here,we describe the identification,cloning and characterization of two Smad genes,the key components of TGF-P signaling pathways,from the Pacific oyster Crassostrea gigas.Sequence analysis of the two genes,designated as cgi-smad1/5/8 and cgi-smad4,revealed conserved functional characteristics.The two genes were widely expressed in embryos and larvae,suggesting multiple roles in the early development of C.gigas.The mRNA of the two genes aggregated in the D quadrant and cgi-smad4 was highly expressed on the dorsal side of the gastrula,indicating that TGF-P signaling pathways may be involved in dorsoventral patterning in C.gigas.Furthermore,high expression levels of the two genes in the shell fields of embryos at different stages suggested important roles for TGF-P signaling pathways in particular phases of shell development,including the formation of the initial shell field and the biomineralization of larval shells.The results of this study provide fundamental support for elucidating how TGF-P signaling pathways participate in the early development of bivalve mollusks,and suggest that further work is warranted to this end.     

本刊声明

<正>为适应我国信息化建设,扩大本刊及作者知识信息交流渠道,本刊数据已被《中国核心期刊(遴选)数据库》《CNKI中国期刊全文数据库》和《中文科技期刊数据库     

国土资源部党组中心组深入学习交流《决定》精神提出要把三中全会赋予的任务落到实处

11月15日下午,国土资源部党组召开党组中心组学习会议,学习、交流党的十八届三中全会通过的《中共中央关于全面深化改革若干重大问题的决定》（以下简称《决定》）。国土资源部部长、党组书记姜大明主持会议,党组副书记徐德明,党组成员汪民、张少农、王世元、王寿祥、胡存智、张德霖出席会议,部总工程师钟自然列席会议。     

深化合作交流 加快制度建设把我国不动产登记工作推向一个新高度——在不动产登记研讨会上的演讲

尊敬的尼古拉斯秘书长,各位来宾、女士们,先生们：时值初夏之际,国土资源部法律中心和国际登记法中心联合举办的“不动产登记研讨会”在北京如期召开。受姜大明部长的委托,我首先代表国土资源部,向来自西班牙的国际登记法中心尼古拉斯秘书长一行,以及全体与会代表的到来,表示热烈的欢迎,并对本次研讨会的成功举办表示衷心的祝贺!     

课堂教学中“过渡”的艺术

正一般而言,完整的教学过程是由一个个具体的教学活动环节组成的,这些环节是教学任务的实施过程,是一个个教学层次,能够反映教学思路的清晰和递进程度。环节之间若缺失了有机的联系,整堂课就会给人拼凑之感,生硬且不连贯,既不利于引导学生循序渐进地建构新知,又难以形成合理的教学节奏,不易赋予课     

中美地理教育的差异

正在美国加州Temple City(天普市)为期两个月的培训期间,与Temple City High School(天普高中)校长如影相随,故称"影子校长"。但作为一名地理教师,除了学习他们的管理,我更感兴趣的还有他们的地理课。通过深入课堂听课,与学校老师学生交流后,我发觉上海和加州两地的地理教育存在比较明显的差异。一、课程名称和课程内容不同美国加州有一门《Earth Science(地球科学)》,属