Long‐term demographic and reproductive trends in Ciona intestinalis sp. A

Ciona intestinalis sp. A (Tunicata, Ascidiacea) is a marine invertebrate with a widespread distribution and high invasive potential, yet little is known about its ecology. Here, the macrodynamics of demographic and reproductive trends were first determined using archive data covering 2002–2012. Species abundance in the central Tyrrhenian Sea (Campania, Italy ‐ NW Mediterranean) displayed Poisson distribution across 2002–2008, massive die‐off in 2009/2010 and population recovery in 2011/2012. We defined the seasonal ranges of sea surface temperature in which sampling size, animal size and reproductive status reached their highest values. In 2003/2004, self and non‐self fertilization appeared to follow reverse trends across the year. The long‐term recording run here on Ciona intestinalis sp. A provides novel insights into its population biology and ecology, and represents a valuable tool for sampling management and research planning.     

三种不同生境的桐花树种群的遗传多样性和遗传分化

采用垂直板型聚丙烯酰胺凝胶电泳测定了三种不同生境的桐花树（Ａｅｇｉｃｅｒａｓ ｃｏｒ ｎｉｃｕｌａｔｕｍ）种群的遗传多样性和遗传分化。桐花树和种群水平都维持有较高的遗传变异性,观察杂合度分别为０．２５２和０．２４４。期望杂合度分别为０．２６６、０．２４０。种群间遗传分化系数为０．１２７,表明总的遗传变异中有１２．７％来自种群间,种群间遗传距离和遗传一致度均值分别为０．０６０和０．９６４,基因流畅,Ｎｍ＝２．１８７。     

Unravelling population structure of black musselcracker Cymatoceps nasutus: evidence for multiple populations in South African coastal waters

Genetic studies on South African marine fishes have shown that many species exist as single, well-mixed stocks throughout their core distribution. The black musselcracker or poenskop Cymatoceps nasutus is a slow-growing, late-maturing and long-lived sparid (Perciformes: Sparidae) that is endemic to South African coastal waters. Conventional tagging studies suggest that it is resident, with limited connectivity between different regions along the coast. Mitochondrial and nuclear DNA were used to investigate the genetic structure of C. nasutus along the South African coastline and showed evidence of at least two populations. Samples collected from the Tsitsikamma Marine Protected Area on the South Coast to KwaZulu-Natal on the East Coast showed no significant population structure over much of the distribution. Gene flow for C. nasutus within this region is not limited by geographic distance and appears to be unaffected by various oceanographic barriers and biogeographical boundaries. Samples from the Western Cape to the west of Tsitsikamma, however, showed moderate to substantial differentiation for both markers, which may be influenced by a temperature barrier – a coldwater ridge – along the South Coast. These data provide the first genetic assessment of this South African sparid, and suggest that a two-stock management strategy would be appropriate for the species.     

基于AFLP技术的海南三亚野生和养殖牡蛎遗传多样性研究

2008年夏季,从海南三亚分别采集26份养殖牡蛎和32份野生牡蛎样品(1份样品代表1个体),开展扩增片断长度多态性(AFLP)和数量性状分析,采用POPGENE 32软件计算多态性位点百分率、遗传多样性指数、Hardy-Weinberg遗传偏离指数、群体遗传相似度和遗传距离。基于AFLP分析获得的遗传距离和线粒体细胞色素氧化酶I亚基(CO I)基因序列,采用邻接法构建养殖和野生牡蛎的系统发育树。结果表明,选择性引物对牡蛎品种具有较好的鉴别效率;相比养殖牡蛎,野生牡蛎多样性丰富、品种间同源性较低、亲缘关系相差较远、遗传基础较宽;通过CO I基因序列分析可知,养殖牡蛎均为香港巨牡蛎Crassostrea hongkongensis,而野生牡蛎属于囊牡蛎属Saccostrea,主要为僧帽牡蛎Saccostrea cucullata。目前海南三亚牡蛎种质资源多样性相对丰富,引种还未对三亚自然环境的牡蛎资源造成明显影响。     

磷、铁营养盐的交互作用对隐藻(Cryptomonas sp.)生长影响的初步研究

利用正交实验设计方法,初步研究和探讨了磷、铁营养盐交互作用对隐藻生长的影响。结果表明,磷、铁营养盐的交互作用(P×Fe)的影响是极其显著的,得出隐藻合适生长铁浓度范围为50 nmol/L~1μmol/L,隐藻生长的培养液最优组合为10μmol/L磷浓度和100 nmol/L铁浓度。     

西施舌3个群体H2A基因和nad6-nad1片段序列比较研究

西施舌(Coelomactra antiquata)浮游幼虫EST序列拼接获得组蛋白H2A ORF及其两翼的非编码区,在ORF两翼设计引物Can-H2AF和Can-H2AR,扩增H2A基因片段;从nad6 3′端和nad1 5′端设计引物,扩增两基因区域DNA序列,测序并进行核苷酸序列差异分析,研究漳州西施舌分化水平。结果:共获得西施舌3个群体H2A基因606bp或616bp基因区DNA片段23条,检测到9种基因型(Gen)。西施舌漳州群体H2A基因AT含量(51.51%)高于日照、北海群体AT含量(50.58%);序列比对分析显示,简约信息位点占4.05%。基于H2A基因的漳州群体与日照/北海混合群体间遗传距离平均为0.044,漳州群体,混合群体内遗传距离分别为0.003和0.004,群体间与群体内遗传距离之比为11~14.7;AMOVA分析结果显示,漳州群体和混合群体间发生了极显著遗传分化(FST=0.937,P0.01)。从nad6~nad1片段中共检出7种单倍型(Hap),漳州群体与日照群体无共享单倍型,基于nad6~nad1的漳州群体与日照群体间遗传距离为0.199~0.202,群体间与群体内遗传距离之比50~66,两个群体间nad1多肽链一级结构存在极大差异,有9个位点的氨基酸不同,日照西施舌缺失6个氨基酸。线粒体DNA显示西施舌漳州与日照群体发生了明显的遗传分化。     

Gene cloning and sequence analysis of the cold-adapted chaperones DnaK and DnaJ from deep-sea psychrotrophic bacterium Pseudoalteromonas sp.SM9913

Pseudoalteromonas sp.SM9913 is a phychrotrophic bacterium isolated from the deep-sea sediment.The genes encoding chaperones DnaJ and DnaK of P.sp.SM9913 were cloned by normal PCR and TAIL-PCR(GenBank accession Nos DQ640312,DQ504163).The chaperones DnaJ and DnaK from the strain SM9913 contain such conserved domains as those of many other bacteria,and show some cold-adapted characteristics in their structures when compared with those from psychro-,meso-and themophilic bacteria.It is indicated that chaperones DnaJ and DnaK of P.sp.SM9913 may be adapted to low temperature in deep-sea and function well in assisting folding,assembling and translocation of proteins at low temperature.This research lays a foundation for the further study on the cold-adapted mechanism of chaperones DnaJ and DnaK of cold-adapted microorganisms.     

基于COI和ITS-1基因对魁蚶野生群体和人工繁育子代的遗传分析

采用线粒体 COI 基因和核糖体第一内转录间隔区 ITS-1基因,对荣成(RC)和即墨(JM)2个魁蚶(Scapharca broughtonii Schrenck)野生地理群体及一个人工繁育的即墨子代(JZ)群体,进行遗传多样性和遗传结构分析,探讨即墨人工繁育的子代作为荣成魁蚶底播增殖苗种的可行性。分子方差分析(AMOVA)结果表明,3个群体的遗传差异主要存在群体内。荣成野生群体和即墨野生群体间的Fst值,基于COI基因和ITS-1基因分别为0.1678和0.1193,表明荣成野生群体与即墨野生群体之间存在中等程度的遗传分化。单倍型多样性和核苷酸多样性分析结果表明,人工繁育的即墨子代群体的遗传多样性明显降低。荣成野生群体与即墨子代群体之间的遗传差异,较之与即墨野生群体间的遗传差异更大。如果采用即墨子代在荣成底播,可能会对荣成野生魁蚶野生群体的遗传结构产生一定影响,因此,采用即墨人工繁育子代作为荣成魁蚶底播增殖的苗种来源时必须十分慎重,并在苗种繁育时尽量采用大群体有效亲本。     

High gene flow promotes the genetic homogeneity of the fish goby Pomatoschistus marmoratus (Risso, 1810) from Mar Menor coastal lagoon and adjacent marine waters (Spain)

The extreme environmental variability of coastal lagoons suggests that physical and ecological factors could contribute to the genetic divergence among populations occurring in lagoon and open‐coast environments. In this study we analysed the genetic variability of lagoon and marine samples of the sand goby, Pomatoschistus marmoratus (Risso, 1810) (Pisces: Gobiidae), on the SW Spain coast. A fragment of mitochondrial DNA control region (570 bp) was sequenced for 196 individuals collected in five localities: Lo Pagan, Los Urrutias and Playa Honda (Mar Menor coastal lagoon), and Veneziola and Mazarrón (Mediterranean Sea). The total haplotype diversity was h = 0.9424 ± 0.0229, and the total nucleotide diversity was π = 0.0108 ± 0.0058. Among‐sample genetic differentiation was not significant and small‐scale patterns in the distribution of haplotypes were not apparent. Gene flow and dispersal‐related life history traits may account for low genetic structure at a small spatial scale. The high genetic diversity found in P. marmoratus increases its potential to adapt to changing conditions of the Mar Menor coastal lagoon.     

转录组学分析B-3胞外多糖对巨噬细胞RAW264.7基因表达的影响

B-3胞外多糖是从一株南极嗜冷菌Psychrobacter sp.B-3发酵液中提取的胞外多糖,前期研究发现该多糖能够激活巨噬细胞并影响其免疫调控活动。为探明其免疫调控途径,采用转录组学分析对经B-3多糖刺激的RAW264.7巨噬细胞系进行了差异表达基因分析。研究结果表明B-3多糖的刺激引起了420个基因的差异表达,其中上调178个、下调242个。差异表达基因与细胞功能存在诸多关联,但主要集中在代谢和免疫两个通路上：其中在多个免疫相关通路上,富集最显著的是抗原处理和表达途径;另一个明显富集的则是代谢通路,B-3多糖处理引起了大量参与代谢的酶类的表达变化,包括氨基酸,碳水化合物,脂质和核苷酸代谢相关基因均发生了一定程度的改变。因此,B-3胞外多糖作为一种免疫激活剂直接影响了RAW264.7巨噬细胞系的免疫功能,同时也对其胞内的代谢途径产生了影响。本论文首次开展了南极嗜冷细菌胞外多糖对RAW264.7巨噬细胞系的影响,该研究为不同来源的活性多糖对巨噬细胞免疫激活研究提供了科学依据。     

不同氮源下南极冰藻Chlamydomonas sp.ICE-L的生物量、氮吸收与脂肪酸组成研究

微藻培养过程中氮缺失有利于油脂和生物量的积累,然而不同氮源条件下微藻生长与生物量的研究有限,限制了生物油脂的相关研究。本文研究通过研究南极冰藻Chlamydomonas sp.ICE-L在不同氮源条件下的细胞生长与油脂积累,进一步探究其作为富集油脂微藻的潜力。研究发现：在含有NH₄CL的培养基中,Chlamydomonas sp.ICE-L生长速率最大;在含有NH₄NO₃的条件下,获得了最大干重量0.28 g/L。最高油脂含量0.21 g/g是在缺氮条件下获得,同时得到干重0.24 g/L。在多不饱和脂肪酸的产出方面,NH₄NO₃和NH₄Cl为氮源培养基时要好于缺氮和KNO₃培养基,在NH₄NO₃和NH₄Cl为氮源的培养条件下ICE-L胞内C18：3和C20：5的含量高。比较而言,缺氮和KNO₃培养基时C16：0、C18：1和C18：2的含量要高。     

Accretion of a New England (U.S.A.) Salt Marsh in Response to Inlet Migration, Storms, and Sea-level Rise

Sediment accumulation rates were determined at several sites throughout Nauset Marsh (Massachusetts, U.S.A.), a back-barrier lagoonal system, using feldspar marker horizons to evaluate short-term rates (1 to 2 year scales) and radiometric techniques to estimate rates over longer time scales (¹³⁷Cs,²¹⁰Pb,¹⁴C). The barrier spit fronting theSpartina-dominated study site has a complex geomorphic history of inlet migration and overwash events. This study evaluates sediment accumulation rates in relation to inlet migration, storm events and sea-level rise. The marker horizon technique displayed strong temporal and spatial variability in response to storm events and proximity to the inlet. Sediment accumulation rates of up to 24 mm year⁻¹were recorded in the immediate vicinity of the inlet during a period that included several major coastal storms, while feldspar sites remote from the inlet had substantially lower rates (trace accumulation to 2·2 mm year⁻¹). During storm-free periods, accumulation rates did not exceed 6·7 mm year⁻¹, but remained quite variable among sites. Based on¹³⁷Cs (3·8 to 4·5 mm year⁻¹) and²¹⁰Pb (2·6 to 4·2 mm year⁻¹) radiometric techniques, integrating sediment accumulation over decadal time scales, the marsh appeared to be keeping pace with the relative rate of sea-level rise from 1921 to 1993 of 2·4 mm year⁻¹. At one site, the²¹⁰Pb-based sedimentation rate and rate of relative sea-level rise were nearly similar and peat rhizome analysis revealed thatDistichlis spicatarecently replaced this onceS. patenssite, suggesting that this portion of Nauset Marsh may be getting wetter, thus representing an initial response to wetland submergence. Horizon markers are useful in evaluating the role of short-term events, such as storms or inlet migration, influencing marsh sedimentation processes. However, sampling methods that integrate marsh sedimentation over decadal time scales are preferable when evaluating a systems response to sea-level rise.