南麂海区养殖贝类的附着生物及其防除研究

2004年7～11月,对南麂马祖岙海区养殖的太平洋牡蛎、海湾扇贝和厚壳贻贝的附着生物进行采样调查,分析了附着生物的种类组成、垂直分布、栖息密度、生物量及波动特征。结果表明,附着生物共有41种,隶属于9个生物门,其中节肢动物有10种,为最多;锯额豆瓷蟹、三角藤壶垂直分布最广;主要优势种为三角藤壶、牡蛎等,不同养殖贝类有不同的优势种;养殖贝类的外部形态与附着生物的附着效果有较大的关系,附着生物对附着体有一定的选择性,台风对附着生物的附着有较大的影响。同时,对在养殖生产中可利用改变吊挂水层、错开附着时间、使用药物等防除措施进行了探讨。     

松辽盆地长岭断陷烃源岩特征与油源对比

长岭断陷层烃源岩和原油样品的地球化学特征分析表明,火石岭—营城组是主要烃源岩,丰度较低、成熟度较高,以Ⅲ型干酪根为主。饱和烃参数、芳烃三芴系列组成特点均表明烃源岩主要形成于微咸－半咸水湖泊的弱氧化－还原环境中,物源以陆源高等植物输入为主,其次为低等水生生物。烃源岩及原油族组分、碳同位素特征、三环萜烷和四环萜烷系列、藿烷系列、芳烃系列分布特征与对比均表明,油源与营城组烃源岩具有较好的亲缘关系。     

大肠杆菌基因编码区碱基分布非均匀性的研究

基于大肠杆菌 １２９２ 个基因编码区．１）统计出了氨基酸丰度分布,与一般生物氨基酸丰度比较发现,构成大肠杆菌蛋白质的氨基酸中疏水氨基酸相对较多,小氨基酸相对较少,二硫键相对较少;２）发现编码区碱基分布的非均匀性与氨基酸丰度的分布和同义密码子的非均匀使用紧密相关;３）分析了编码开始区域、编码终止区域碱基分布和氨基酸丰度分布的差别,得到了一些有意义的结论．     

湘中晚泥盆世Yunnanella-Yunnanellina群落分析

利用生态地层工作方法分析了湘中晚泥盆世锡矿山阶Yunnanella-Yunnanellina群落的生物组成、分异度、相对丰富度、空间分布及基底物质性质。据一些种群的大小频率直方图和生存曲线讨论了部分生物的生存特征、空间分布及其与环境的关系。文章还对该群落中生物的生态、营养结构及生境特征进行了分析。     

湘中晚泥盆世早期的两个古群落分析

利用生态地层工作方法对湘中晚泥盆世早期的化石群落进行了研究,并划分出两个古群落,较详细地分析了各群落的生物组成、分异度、相对丰富度、生物的生活方式、基底物质性质等。群落总是与其生存的特定空间环境相联系,每个群落有其自身的生物组成和发展过程。     

SAR11 clade dominates ocean surface bacterioplankton communities

The most abundant class of bacterial ribosomal RNA genes detected in seawater DNA by gene cloning belongs to SAR11-an alpha-proteobacterial clade. Other than indications of their prevalence in seawater, little is known about these organisms. Here we report quantitative measurements of the cellular abundance of the SAR11 clade in northwestern Sargasso Sea waters to 3,000 m and in Oregon coastal surface waters. On average, the SAR11 clade accounts for a third of the cells present in surface waters and nearly a fifth of the cells present in the mesopelagic zone. In some regions, members of the SAR11 clade represent as much as 50% of the total surface microbial community and 25% of the subeuphotic microbial community. By extrapolation, we estimate that globally there are 2.4 x 10(28) SAR11 cells in the oceans, half of which are located in the euphotic zone. Although the biogeochemical role of the SAR11 clade remains uncertain, these data support the conclusion that this microbial group is among the most successful organisms on Earth.     

石花菜筏式栽培敌害生物及其防治

主要通过苍南县沿浦湾石花菜栽培期间的常见敌害生物种类、分布和丰度情况的调查,了解其生物学特征,借鉴大型海藻栽培敌害防治的经验,进行石花菜栽培敌害生物防治技术研究,以期对石花菜栽培业可持续健康发展有所助益。     

Origin and evolution of new exons in the rodent zinc finger protein 39 gene

The origin of new structures and functions is an important process in evolution. In the past decades, we have obtained some preliminary knowledge of the origin and evolution of new genes. However, as the basic unit of genes, the origin and evolution of exons remain unclear. Because young exons retain the footprints of origination, they can be good materials for studying origin and evolution of new exons. In this paper, we report two young exons in a zinc finger protein gene of rodents. Since they are unique sequences in mouse and rat genome and no homologous sequences were found in the orthologous genes of human and pig, the young exons might originate after the divergence of primates and rodents through exonization of intronic sequences. Strong positive selection was detected in the new exons between mouse and rat, suggesting that these exons have undergone significant functional divergence after the separation of the two species. On the other hand, population genetics data of mouse demonstrate that the new exons have been subject to functional constraint, indicating an important function of the new exons in mouse. Functional analyses suggest that these new exons encode a nuclear localization signal peptide, which may mediate new ways of nuclear protein transport. To our knowledge, this is the first example of the origin and evolution of young exons.     

温州海区长蛇鲻寄生线虫幼虫的分布模式

作者对温州海区常见30多种经济鱼类作为中间宿主感染寄生虫的情况进行了调查,结果表明15．2％的被检鱼类寄生单殖吸虫,而63．6％的被检鱼类有线虫寄生,文中着重对不同体长组长蛇鲻体内寄生线虫的状况进行研究,随着宿主体长的增长,其感染强度和平均密度有逐渐增加的趋势,宿主体内寄生率及密度占绝对优势的Anisakis simplex幼虫和Contracaecumsp,幼虫在宿主体内的频率分布,表明多数宿主不感染或只感染少量的线虫幼虫,少数宿主感染线虫幼虫数量较大,线虫幼虫在宿主种群的分布格局类型均为聚集分布。     

鄂尔多斯盆地南部烃源岩沉积环境研究

目的探讨鄂尔多斯盆地南部烃源岩沉积环境与地球化学特征的关系。方法以井下剖面烃源岩的地球化学分析资料为主，依据有机碳含量分布、有机质类型及饱和烃气相色谱等特征对烃源岩的沉积环境进行了研究，分析了沉积环境对有机质丰度和类型的影响因素，探讨了鄂尔多斯盆地南部烃源岩沉积水体的主量元素、古气候及古盐度条件。结果鄂尔多斯盆地南部烃源岩层系沉积时气候潮湿，沉积水体的古盐度较淡；半深湖-深湖相带沉积的还原程度强、有机质能被及时埋藏的灰黑色泥岩,大多有机质丰度高、有机质类型好；河流-沼泽相带沉积的灰色-绿灰色泥岩类烃源岩有机质丰度较低、有机质类型偏差。结论还原程度强、具一定深度水体的沉积相带是原始有机质沉积的良好场所，有机质能及时沉积、保存下来，烃源岩有机质丰度大多高；气候条件相对干燥、大气降水少、陆源碎屑物补充不足或较长时间处于氧化程度较高条件下沉积的碳酸盐岩类岩石．有机质丰度明显偏低。     

Dynamic response of Permian brachiopod communities to long-term environmental change

The fossil record preserves numerous natural experiments that can shed light on the response of ecological communities to environmental change. However, directly observing the community dynamics of extinct organisms is not possible. As an alternative, neutral ecological models suggest that species abundance distributions reflect dynamical processes like migration, competition, recruitment, and extinction. Live-dead comparisons suggest that such distributions can be faithfully preserved in the rock record. Here we use a maximum-likelihood approach to show that brachiopod (lamp shell) abundance distributions from four temporally distinct ecological landscapes from the Glass Mountains, Texas (of the Permian period), exhibit significant differences. Further, all four are better fitted by zero-sum multinomial distributions, characteristic of Hubbell's neutral model, than by log-normal distributions, as predicted by the traditional ecological null hypothesis. Using the neutral model as a guide, we suggest that sea level fluctuations spanning about 10 Myr altered the degrees of isolation and exchange among local communities within these ecological landscapes. Neither these long-term environmental changes nor higher-frequency sea level fluctuations resulted in wholesale extinction or major innovation within evolutionary lineages.     

生殖域中特异表达的新基因Rcet2的克隆

利用NCBI中的数字差异显示数据库首先电子克隆了Rcet2基因,然后从成年小鼠睾丸组织中克隆出Rcet2全长基因,序列分析显示：Rcet2基因全长cDNA为454 bp,含3个外显子,编码88个氨基酸残基,该蛋白含1个不完整的半胱氨酸蛋白酶抑制剂结构域,但缺少半胱氨酸蛋白酶抑制剂关键的作用位点,而这些位点对半胱氨酸蛋白水解酶的抑制作用是重要的.小鼠多组织RT-PCR结果显示,Rcet2在成年老鼠大脑、睾丸和附睾生殖域中特异表达,睾丸中的表达高于附睾和大脑,Rcet2与半胱氨酸蛋白酶抑制家族2的Cres亚家族具有相似的特征,结果显示Rcet2可能是Cres亚家族中的一个新成员.     

风化校正作用在烃源岩有机地化研究中的应用

通过对哈密拗陷下二叠统野外剖面观察和样品采集,运用岩石热解、有机碳测试、干酪根分析及饱和烃气相色谱等技术进行室内样品测试,在与前人分析数据相结合的基础上,利用风化校正作用对哈密拗陷下二叠统露头烃源岩有机质丰度、有机质类型进行评价,同时探讨了有机质成熟度、原始沉积环境和生源特征.结果表明,哈密拗陷下二叠统烃源岩属于好—很...     

Microbialite resurgence after the Late Ordovician extinction

Microbialites, including biogenic stromatolites, thrombolites and dendrolites, were formed by various microbial mats that trapped and bound sediments or formed the locus of mineral precipitation. Microbialites were common and diverse during the Proterozoic, but declined in abundance and morphological diversity when multicellular life diversified during the Cambrian Radiation. A second decline occurred during the Ordovician Radiation of marine animals, and from then until the present microbialites have been confined largely to high-stress environments where multicellular organisms are rare. The microbialite declines in the Phanerozoic are attributed to disruption of the mats by animals. A resurgence of stromatolite abundance and size during reduced animal diversity after the Permian extinction has been documented anecdotally. Here we show, with statistical support, that a microbialite resurgence also occurred after the Late Ordovician extinction event in western North America. The resurgences were associated with loss of mat-inhibiting animals, providing insights into shallow-water community structures after extinction events.     

荒漠地区土壤表层固碳作用研究进展

 干旱、半干旱地区的生态环境条件脆弱,光能自养生物在荒漠地区地表的物质循环和能量流动中起着重要作用。藻类和苔藓是荒漠地区地表普遍存在的固碳生物,不仅能够改善土壤的物理性质,起到保护土壤的作用,同时能够通过特定蓝藻的固氮作用增加土壤的氮含量,最重要的是这些固碳生物能够通过光合作用固定空气中的CO₂,是荒漠地区土壤表层固碳的主要贡献者。荒漠地区生态系统固碳量的研究也是研究全球气候变化的重要组成部分,固碳量的大小不仅受自然条件的约束,也与土壤表层固碳生物（主要是藻类和苔藓）的组成密切相关。当土壤中仅有丝状蓝藻存在时固碳速率较低,随着绿藻等高等藻类和苔藓的出现,固碳速率快速增加。本文综述了荒漠地区土壤表层固碳生物组成和影响地表固碳的因素,回顾和展望了地表固碳的研究方法。     

双歧杆菌与嗜热链球菌混菌培养研究

研究了短双歧杆菌（Ｂｉｆｉｄｏｂａｃｔｅｒｉｕｍｂｒｅｖｅ）和嗜热链球菌（Ｓｔｒｅｐｔｏｃｏｃｃｕｓｔｈｅｒｍｏｐｈｉｈｕｓ）的选择性培养条件,探讨了两菌在单一菌种培养和混菌培养状况下的菌体生长和产酸特点,发现该两菌种之间的生长及产酸存在着明显的互相促进作用,在牛乳培养基中混菌培养状况下两菌的生长及产酸代谢均优于单菌种培养．在两菌的接种量体积分数各为１％的条件下,不但能获得较高的活菌数,而且凝乳状态及风味都比较好．     

油菜对Cd污染土壤的修复潜力分析

以甘蓝型油菜为研究材料,利用盆栽试验研究了不同浓度Cd(0,1,2mg/kg)胁迫下油菜的吸收特性,以及土壤微生物群落结构变化.结果表明:随着Cd浓度的升高,油菜植株对Cd的吸收显著增加,而且油菜地上部分的吸收量显著高于地下部分,其中茎的Cd浓度最高,籽粒最低;油菜将Cd从地下转移到地上部分的转运系数随外源Cd浓度的升高而呈现先升高后下降的趋势;且低浓度Cd处理下,油菜对Cd的转运系数较高,修复效率可以达到6.841%~7.752%.土壤微生物多样性分析发现,Cd改变了土壤微生物群落的结构,降低了部分优势菌群的相对丰度,而油菜可以增加这些菌群的相对丰度,提高土壤微生物多样性.因此,种植油菜有利于土壤生态系统的稳定性,可以用于修复中等程度Cd污染土壤.     

Comparison between phylogeny of introns and exons in primates

Introns and exons of 7 genes ( epsilon globin, gamma-1 globin, gamma-2 globin, delta globin, beta globin, Immunoglobulin and prepro-insulin) in primates have been separated out and used to infer phylogeny respectively. For each gene, results based on these two parts have been compared and showed that: ( i ) the topology of introns is almost consistent with that of exons in each gene, while the branch length of them varies, because of the different mutation rate; ( ii ) there is evidence that the substitution rate of exons would decrease in hominoids, but that of introns would not; (iii) divergence time of orangutan deduced from different genes based on exons is various, while that based on introns is much similar, and consistent with fossil records; (iv) there is a relationship between the G + C content and the substitution rate. When the substitution rate of introns is higher than exons in a gene, the G + C content of introns is less. The above results suggest that introns could provide useful evolutionary information among closely related species.