鼠尾藻有性繁殖和幼孢子体发育的形态学观察

野外跟踪观测烟台芦洋湾地区鼠尾藻的成熟繁殖状况,采集临近成熟的鼠尾藻至实验室培养,跟踪观测其卵子的排放、卵子和受精卵的发育、假根的生长以及幼孢子体的前期发育。试验结果表明,本地区鼠尾藻繁殖期集中在6—8月,鼠尾藻的卵子发育属8核1卵型,卵子受精后约20 h开始脱离生殖托,受精卵先连续进行2次的横分裂,而后再由一端的1个细胞发育成假根,另外2个发育成体细胞。幼孢子体在约2 mm时开始形成分枝突起。     

鼠尾藻的有性繁殖过程和幼苗培育技术研究

重点研究了鼠尾藻的有性繁殖特性和规律,系统观察了鼠尾藻的成熟季节,雌、雄生殖托的成熟、排卵、排精、受精卵的细胞分裂、假根的形成、幼孢子体的构建和生长特征。并在实验室进行采苗和苗种培育试验,获得理想结果,该培育技术可以应用到生产中。     

莫氏马尾藻繁殖生物学初步研究

观察了莫氏马尾藻在成熟季节雌、雄生殖托的繁殖特点、受精卵的形成、假根的发育、幼孢子体生长特征,并研究了不同附着基对采苗效果的影响。试验结果表明,莫氏马尾藻的繁殖盛期为4月中旬至5月中旬,其卵子发育属八核一卵型,假根是由基部一个细胞分化发育而来;瓷砖附苗的密度超过40株/cm2,在培育15d后,幼孢子体长度约1～2mm。     

光、温对鼠尾藻卵子排放和幼孢子体生长的影响

以成熟的鼠尾藻生殖托为材料,研究了不同温度(13～23℃)、光照度(3000～12000lx)和光照周期(15L∶9D,12L∶12D,9L∶16D)对鼠尾藻排卵及幼孢子体生长的影响。结果显示,温度在20～23℃范围,有利于鼠尾藻卵子的排放;在3000～12000lx范围内,光照度越高,越有利于鼠尾藻卵子的排放;光周期不是影响卵子排放的主要因素,光照度是鼠尾藻幼孢子体生长的重要因子;温度是制约鼠尾藻幼孢子体生长的关键因子,水温低于16℃时不利于幼孢子体的快速生长。     

鼠尾藻幼苗的室内培养及有性生殖同步化

为了优化鼠尾藻幼苗生长与同步生殖的室内培养条件,实验以长度为5 cm左右的鼠尾藻幼苗为材料,在培养箱中给予不同的温度、光照强度和营养盐配比［KNO₃(mg)∶KH₂PO₄(mg)］等生长条件,通过跟踪测量生长情况,观察记录幼苗形态变化、生殖器官形成及生殖特点,寻找有利于幼苗室内生长和繁殖的适宜组合条件,实现生殖托提前发育和受精作用的同步化。实验结果表明,培养条件对鼠尾藻幼苗长度增长率的影响为温度>营养盐配比>光照强度;对质量增长率的影响为温度>光照强度>营养盐配比。培养温度越低气囊出现时间越早。侧枝的生成与营养盐配比具有一定的关系,总体上营养盐中KH₂PO₄所占比例越高侧枝出现时间越晚。生殖托生成的时间受到温度的影响最为显著。实验中受精卵的形成与脱落也明显受到温度的调节,温度越高生殖托生长越缓慢,卵受精时间越晚。光照越强藻体色素含量越低。室内培养的鼠尾藻完成繁殖过程比自然生长的个体提前3～4个月,并且平均每克藻体可以采苗约300棵。     

温度对于长柄羽叶藻幼孢子体生长的影响

1.15℃为长柄羽叶藻幼孢子体最佳生长温度,10～20℃为适宜生长温度。长时间把温度控制在23℃以上,对幼孢子体生长有抑制作用。幼孢子体在26℃水温中8～10天后停止生长。 2.长柄羽叶藻幼孢子体假根在10～20℃水温中都能正常生长发育,以15℃组最佳。高温组(23、26℃组)假根生长发育不良,常呈球状,无明显分枝。 3.长柄羽叶藻可以在青岛海区度夏。     

褐藻羊栖菜繁殖生物学特征和生活史流程的补充研究

以温州市洞头区人工养殖羊栖菜和野生羊栖菜为研究样本,详细描述了羊栖菜成熟孢子体有性生殖,假根与侧生枝无性生殖的繁殖生物学特征和生活史流程。详细记录了羊栖菜卵、精子和受精卵的减数分裂和有丝分裂过程,假根、茎(主茎和侧生茎)、叶(气囊)和生殖托(雌托和雄托)等4类器官生长、发育和分化过程,胚、幼孢子体和成熟孢子体形态结构特征。在此基础上对现有羊栖菜繁殖生物学特征及生活史流程进行了补充和修正,增加了羊栖菜侧生枝无性生殖和羊栖菜幼孢子体期有性生殖的相关内容,并重新绘制了羊栖菜生活史流程图。该研究结果将为开展羊栖菜养殖生态学研究,深层次解析羊栖菜生殖节律、种群繁衍与环境关系奠定基础。     

鼠尾藻幼孢子体培育条件探究

为探究鼠尾藻Sargassum thunbergii幼孢子体早期生长发育适宜的培养条件,设置了光照度、温度、盐度3个影响因素3个水平的正交实验,以及氮磷营养盐水平实验。研究表明,温度对鼠尾藻幼孢子体的生长影响最显著（P〈0．05）,25℃时幼孢子体比生长速率（sGR）获得最大值,为10．78％,随着温度的降低sGR逐渐降低;盐度对幼孢子体的SGR影响显著（P〈0．05）,盐度30时幼孢子体生长较快,盐度降低SGR也降低;光照度2000～8000lx对幼孢子体的生长影响不显著,SOR极差接近误差水平。氮磷营养盐水平对鼠尾藻幼孢子体的生长影响较大,实验用自然海水中氮素基本可以满足幼孢子体的需求,而磷元素相对缺乏。氮素加富条件下,氮磷比大于15：1时不利于幼孢子体的生长,适宜的氮磷比为10：1～2：1。结果表明,温度25℃、盐度30、光照度20001x是鼠尾藻幼孢子体早期生长发育适宜的条件。培养液氮素含量保持在0．45～1mg/L,磷含量保持在0．3mg/L左右有利于幼孢子体快速生长。     

巨藻早期假根的形成与生态的研究

1.在巨藻生长发育过程中,依附着器的变化,可划分为卵囊附着期、假根毛附着期、吸附盘附着期和假根附着期四个时期。2.假根毛的各生长阶段形态不同,在生长后期的部分假根毛顶端产生叉状分枝。3.大于1毫米的幼藻,假根毛的数量随光强的提高而增加。有趣的是生长在尼龙丝上、位于弱光下的幼藻,它们的假根毛通常螺旋状缠绕在尼龙丝上。4.幼藻的早期假根与成藻假根一样,有明显的背光性。5.10～15℃的水温,是早期假根产生的最佳范围。6.在巨藻幼苗的生产中,除掌握适当的采孢子密度和适宜光照、温度外,选择适当的附着基,经常保持育苗器的清洁,让幼藻各阶段的附着器,都能直接接触育苗器,是避免脱苗保持苗全苗旺的有效措施之一。     

不同光照周期对羊栖菜有性繁殖过程的影响

对羊栖菜的生殖托在不同光照周期条件下进行离体培养,观察卵细胞的释放与受精情况,以及受精卵的发育情况,以探讨光照周期对其有性繁殖过程的影响.试验结果表明,长光照周期可以明显促进卵子的排放,延长卵子的存活时间,提高卵子的受精效率,有利于合子的发育与生长.在羊栖菜通过有性繁殖途径进行的苗种生产过程中,较长的光照周期有利于提高苗种生产效率.     

Movement of the fluvial form of masu salmon, <Emphasis Type="Italic">Oncorhynchus masou masou</Emphasis>, in a mountain stream in Kyushu,Japan

Using mark-recapture methods, the movements of the fluvial form of masu salmon (Oncorhynchus masou masou) in a mountain stream on the island of Kyushu, Japan, were studied. Most (78%) of the masu salmon were recaptured in the pool in which they had been originally caught and tagged. Of those that moved between pools, the proportion of individuals that moved during the breeding period was not significantly higher than the proportion that moved during the non-breeding period. However, during the breeding period, a higher proportion of larger salmon moved than did smaller fish. The proportion of mobile large males during breeding period was higher than that for small males. Also, it was found that a few individuals showed long-range movement in the autumn. As a long-term movement, 78 individual fish (65%) that were recaptured more than three times showed high sedentary tendencies. Sixteen individual mobile fish (13%) moved and returned to the original pool. Fluvial form of masu salmon in Kyushu show a high sedentary nature; however, large mature males seem to actively move in search of female during breeding period.     

Characteristics of the marine environment and algal blooms in Gamak Bay

This study was conducted to gain insight into the characteristics of algal blooms in relation to the marine environment of Gamak Bay. From the first known occurrence of algal blooms in 1984 until 2006, 23 causal species have been identified, the most common ones being Prorocentrum sp., Cochlodinium polykrikoides, Chaetoceros sp., Skeletonema costatum, and Heterosigma akashiwo. A principal component analysis indicated that blooms of these species develop under different conditions in terms of water temperature, salinity, precipitation, and insolation. Field data showed Cochlodinium polykrikoides to be favored by high temperatures and to be euryhaline, whereas Skeletonema costatum appeared to be eurythermal and euryhaline. Prorocentrum sp. and Chaetoceros sp. appeared to be stenothermal and stenohaline. Finally, Heterosigma akashiwo appeared at the lowest temperature and highest salinity of the five species and was classified here as stenothermal and stenohaline.     

Antifreeze proteins in the urine of marine fish

Several species of marine teleosts have evolved blood plasma antifreeze polypeptides which enable them to survive in ice-laden seawater. Four distinct antifreeze protein classes differing in carbohydrate content, amino acid composition, protein sequence and secondary structure are currently known. Although all of these antifreezes are relatively small (2.6–33 kd) it was generally thought that they were excluded from the urine by a variety of glomerular mechanisms. In the present study antifreeze polypeptides were found in the bladder urine of winter flounder (Pseudopleuronectes americanus), sea raven (Hemitripterus americanus), ocean pout (Macrozoarces americanus) and Atlantic cod (Gadus morhua). Since the plasma of each of these fish contains a different antifreeze class it would appear that all four classes of antifreeze can enter the urine. The major antifreeze components in the urine of winter flounder were found to be identical to the major plasma components in terms of high performance liquid chromatography retention times and amino acid composition. It is concluded that plasma antifreeze peptides need not be chemically modified before they can enter the urine.     

四种鲍45S rDNA在染色体上的比较定位

为了研究皱纹盘鲍、西氏鲍、绿鲍和杂色鲍等4种鲍的核型特征,实验利用荧光原位杂交(fluorescence in situ hybridization, FISH)技术比较定位了上述4种鲍的45S rDNA位点。皱纹盘鲍中约83%的中期细胞均检出2对45S rDNA位点,分别位于13号和16号染色体的长臂端部。西氏鲍中约75%的中期细胞均检出3对45S rDNA位点,分别位于6号染色体短臂端部、14号和17号染色体长臂端部。绿鲍中约85%的中期细胞均检出3对45S rDNA位点,分别位于4号、6号和8号染色体长臂的端部。杂色鲍中约65%的中期细胞均检出3对45S r DNA,位点,分别位于3号、4号和12号染色体短臂的端部。此外,4种鲍均有少数中期相的45S rDNA位点数高于众数,这提示,除了明确的45S rDNA位点外,4种鲍可能均有若干个不稳定的45S rDNA位点。实验结果丰富了鲍细胞遗传学研究资料,同时为鲍的遗传育种研究提供了基础数据。     

Bioaugmentation in the growth and water quality of livebearing ornamental fishes

Bacillus subtilis isolated from the intestine of Cirrhinus mrigala (Hamilton) was incorporated into the rearing water of Poecilia reticulata (Peters), Poecilia sphenops (Valenciennes), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Gunther) at four different concentrations (5 × 10⁸ cells ml⁻¹, 5 × 10⁷ cells ml⁻¹, 5 × 10⁶ cells ml⁻¹ and 5 × 10⁵ cells ml⁻¹) and its effect on fish growth performance and survival, water quality parameters and bacterial population of water were assessed. The results showed that the addition of bacterial cells in the rearing water resulted in greater survival and a faster growth rate and, hence, greater length and weight increments of the livebearers. The use of a bioaugmentor in the rearing water of the livebearing fishes resulted in significantly lower (P < 0.05) concentrations of dissolved organic matter and total ammonium nitrogen. The counts of motile aeromonads and total coliforms recorded in the water of bioaugmented tanks were also lower than that in the control tank. Bioaugmentation between 10⁶ and 10⁸ cells ml⁻¹ in the rearing water is sufficient in establishing a bioaugmentor and the use of a higher concentration of bacterial cells did not always lead to significantly better results.     

中国3种青鳉鱼类初孵仔鱼发育与形态比较

对中国珠江流域及邻近区域主要的青鳉鱼类中华青鳉(Oryzias sinensis)、鳍斑青鳉(Oryzias pectoralis)和弓背青鳉(Oryzias curvinotus)初孵仔鱼形态特征进行了观察。研究结果显示,在水温(27.0±1.0)℃水浴孵化条件下, 3 种青鳉鱼类初孵仔鱼形态存在差别。鳍斑青鳉初孵仔鱼体长为(4.64±0.18) mm,显著大于中华青鳉[体长(4.04±0.19) mm]及弓背青鳉[体长(3.88±0.17) mm]的初孵仔鱼。单因素方差分析显示,三者在 22 个形态测量及可数性状指标中 20个指标(占 90.9%)存在显著差异(P<0.05)。主成分分析显示,体全长、头长、头长/体高、体长/体高、肛后长、口宽及卵长径等指标是影响三者形态差异的主要因素。判别分析进一步表明三者形态差异明显,且易于区分。单因素相似性分析(ANOSIM)更进一步证实三种青鳉初孵仔鱼形态差异具有统计学意义。聚类分析显示,鳍斑青鳉与弓背青鳉初孵仔鱼形态更为接近,中华青鳉初孵仔鱼独立成一类,该结果与 3 个物种间地理分布格局远近情况相同。更为浓密的背部及腹部色素特征可以将中华青鳉初孵仔鱼与其余两个物种初孵仔鱼区别,胸鳍上点状色素花特征则可进一步将鳍斑青鳉与弓背青鳉初孵仔鱼区分。另外,众多形态测量指标也可以将鳍斑青鳉及弓背青鳉初孵仔鱼区分。     

泥蚶34个EST-SSR标记的开发及在格粗饰蚶中的通用性检测

利用泥蚶转录组高通量测序、拼接获得的大量EST序列开发SSR标记,在1123条EST序列里筛查到73条含有SSR位点的EST序列,其中54个位点适合设计引物,在位点两侧设计引物并进行PCR扩增.结果显示,46对引物获得稳定扩增的位点,引物在泥蚶奉化群体的多态性检测中发现,有34对引物表现出多态性,共扩增出122个等位基因,各位点的等位基因数Na为2～7个,平均每个位点产生3.59个等位基因,观测杂合度Ho、期望杂合度He、多态信息含量PIC范围分别为0.000 ～ 0.600、0.078 ～0.771、0.106～0.718;Hardy-Weinberg平衡检测显示,13个位点偏离了平衡状态;用Nr和Swiss-Prot蛋白质数据库对含有多态性SSR的EST进行了基因注释,25个SSR位点来自注释基因序列.将34对泥蚶多态性SSR引物在格粗饰蚶中进行了通用性检测,结果有1 1对成功扩增,8对表现为多态,通用率为23.53％,这些通用引物可用于两种蚶的遗传多样性评价、系统进化分析、比较作图和基因发掘等研究.     

Identification of Stress Sensitive Genes in Hyperthermic Atlantic Salmon (Salmo salar) Embryos by RAP-PCR

Deformities of skeletal structures, the heart, and other organs are a recurrent problem in species used in intensive aquaculture. Elevated egg incubation temperature appears to be a high risk factor in the development of these malformations, but the causal relation has not been established. Our aim was to identify candidate genes involved in the development of heat induced deformities in Atlantic salmon (Salmo salar). Temperature sensitive genes were isolated by RNA Arbitrarily Primed (RAP)-PCR. A total of 33 RAP-PCR products were successfully sequenced, and the expression of eight identified genes was further examined by RT-PCR from pooled samples of heat exposed embryos. Five of these genes were demonstrated to be temperature sensitive, of which four were shown to be up-regulated and one was down-regulated at elevated water temperatures. The atrial natriuretic peptide (ANP) gene, which is a promising candidate for heart deformities, showed the highest level of heat induction. Three additional RAP-PCR products identified as heterogeneous nuclear ribonucleprotein (hnRNP) A0, acyl CoA binding protein (ACBP) and mitochondrial (mt)-HSP70 showed up-regulated mRNA expression in response to elevated water temperature. The single down-regulated gene was identified as an Atlantic salmon (Salmo salar) homolog of the cysteine and tyrosine-rich 1 (CYYR1) gene. This study demonstrated that a temperature elevation of only 4 °C during the early stages of the organogenesis in Atlantic salmon induce altered expression of a number of genes, which are candidates for the development of heat induced deformities.     

日本鳗鲡TRAF3基因的克隆及功能研究

为探究鱼类TRAF3在鱼类抗病毒免疫应答中的功能及作用机制,实验利用逆转录PCR克隆获得了日本鳗鲡TRAF3转录本 (AjTRAF3),利用生物信息学软件分析了AjTRAF3的结构特征,利用实时荧光定量 PCR(qPCR)、双荧光素酶报告系统以及免疫共沉淀等方法对其表达规律、功能及作用机理进行了初步分析。AjTRAF3的开放阅读框长度为1 707 bp,编码568个氨基酸。序列结构分析结果显示,AjTRAF3由N端的环结构域2个锌指结构域以及1个螺旋结构域和C端高度保守的TRAF-C (MATH)结构域组成。qPCR结果显示,AjTRAF3在日本鳗鲡各组织中均有表达,脑组织中表达量最高,其次为头肾,心脏中的表达量最低。Poly I:C刺激6 h后,日本鳗鲡脾脏组织中AjTRAF3上调倍数最高,为对照组的15.83倍。迟缓爱德华氏菌感染24 h后,日本鳗鲡脾脏组织中AjTRAF3上调倍数最高,为对照组的31.47倍。此外,本研究构建了AjTRAF3真核表达质粒,发现过表达AjTRAF3能显著上调炎症及抗病毒相关基因的表达,可显著增强AjIFN2、AjIFN4和NF-κB启动子荧光素酶活性。并能显著上调由AjRIG-IN、AjMAVS、AjIRF3诱导的AjIFN2、AjIFN4和NF-κB启动子活性。免疫荧光结果显示,AjTRAF3主要定位于细胞质中,且与AjMAVS存在共定位。免疫共沉淀结果显示,AjTRAF3通过MATH结构域与AjMAVS相互结合,缺失该结构域后,其与AjMAVS的相互作用消失,推测AjTRAF3可通过介导RIG-I/MAVS信号转导途径调控鱼类的抗病毒免疫应答。本研究结果为进一步揭示鱼类TRAF3的生物学功能奠定了基础。     

二氧化锗对共培养萱藻丝状体和硅藻生长的影响

为抑制萱藻丝状体保存和扩增过程中出现的小伪菱形藻与碎片菱形藻的生长,本实验应用实验生态学方法,分别建立了丝状体与小伪菱形藻、丝状体与碎片菱形藻、丝状体与小伪菱形藻和碎片菱形藻的共培养体系,研究了1.00～4.00μg/mL二氧化锗(GeO_2)对共培养条件下丝状体生长发育及附生硅藻生长的影响。结果显示:(1)处理萱藻丝状体和硅藻共培养体系的适宜GeO_2浓度为1.00～2.50μg/mL,各实验组14 d的硅藻抑制率均高于67.33%±5.18%,且丝状体生长发育良好,2.00μg/mL为最适浓度,此浓度下丝状体日均增长率最高,在各培养体系中均大于11.00%,且诱导后孢子囊枝比例和孢子囊直径分别为57.47%±5.31%和(24.55±1.01)μm,与对照组差异不显著;(2) 3.50和4.00μg/mL GeO_2虽对硅藻抑制效果更佳,但同时也会抑制丝状体生长和后期孢子囊的形成与发育,其中4.00μg/mL GeO_2可导致丝状体死亡;(3)碎片菱形藻较小伪菱形藻对GeO_2更敏感。实验14 d,各浓度GeO_2对碎片菱形藻的抑制率为(82.10%±2.40%)～(96.35%±0.79%),均高于同浓度GeO_2对小伪菱形藻的抑制率;同时在丝状体与小伪菱形藻和碎片菱形藻的共培养体系中,碎片菱形藻占硅藻比例随GeO_2浓度升高而相应下降。