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1.
中华乌塘鳢(Bostrichthys sinensis) 和大弹涂鱼( Boleophthalmus pectinirostris) 成熟产卵过程中17a-羟基孕酮和前列腺素水平的研究 总被引：5，自引：2，他引：5
以酶联免疫吸附分析法测定了中华乌塘鳢和大弹涂鱼成熟产卵过程中卵巢液、精巢液、贮精囊液、雌鱼尿液和雄鱼尿液中的17α-羟基孕酮(17α-P)、前列腺素E2(PGE2)和前列腺素R2α(PGF2α)的含量。结果表明，中华乌塘鳢卵巢液中的17α-P和PGE，含量随着卵巢发育成熟而升高。性成熟前后卵巢液中的PGE，含量高于PGF2α。性成熟雄鱼尿液和贮精囊液中的PGE2含量显著高于精巢液或雌鱼尿液。性成熟前后雌鱼尿液中的17α-P、PGE2和PGF2α含量均显著高于卵巢液。性成熟和退化期雌鱼尿液中的PGE2含量明显高于PGF2α。性未成熟大弹涂鱼(第Ⅳ期)卵巢液中PGE2和PGF2α，含量极低；性成熟时(第V期)卵巢液中的PGE2、PGF2α和17α-P含量显著上升，PGF2α含量显著高于PGE2。 相似文献
2.
采用酶联免疫吸附法测定了野生中华鸟塘鳢（Bostrichthyssinensis）不同季节血清E2和1l—KT含量的变化,并比较了生殖季节养殖雌雄同体与野生雌雄异体之间E,、11一KT和17仪,2013一P三种性类固醇激素含量的差异．结果表明,野生雌鱼和雄鱼血清E：和11一KT的含量均具有明显的季节变化,其高低均依次为5〉8〉2〉11月．在相同月份,雌鱼的E,含量显著高于雄鱼,而雄鱼的ll—KT含量显著高于雌鱼．生殖高峰期,雌雄同体E：含量高于雌雄异体雄鱼,但低于雌雄异体雌鱼;雌雄同体l1一KT和17仅,20]3一P含量均高于雌雄异体雌鱼和雄鱼;野生雌鱼和雄鱼血清170L,2013一P含量没有显著差异．性类固醇激素在中华鸟塘鳢的生殖过程中起着重要作用,E：是野生中华乌塘鳢雌鱼的主要雌激素,而11一KT则是野生雄鱼的主要雄激素． 相似文献
3.
红树林因其独特的生长环境,具有重要的生态、经济和社会意义。中华乌塘鳢(Bostrychus sinensis)是我国优良的养殖品种。为提高红树林的生态与经济效益,对红树林下中华乌塘鳢铁笼养殖技术进行研究探讨,并分析比较红树林下养殖鱼、光滩笼养鱼与野生鱼肌肉的营养成分。结果显示:以上各组鱼体的粗蛋白含量均较高(74.65%~83.08%),粗脂肪含量较低(0.89%~1.63%),其中红树林下养殖鱼的粗蛋白和粗脂肪含量分别高于光滩养殖鱼;各组实验鱼的氨基酸总量(71.72%~79.27%)、鲜味氨基酸总量(29.03%~30.92%)、必需氨基酸总量(27.47%~31.57%)、非必需氨基酸总量(44.25%~47.69%)均以野生鱼为最高,光滩投饵组最低,红树林下养殖组高于光滩养殖组;各组实验鱼肌肉必需氨基酸指数EAAI均较高(66.83~74.90),限制性氨基酸为缬氨酸、异亮氨酸和(蛋+胱)氨酸,支链氨基酸总量/芳香族氨基酸总量(F值)为2.17~2.22;红树林下养殖鱼肌肉中的n-3系列多不饱和脂肪酸含量和(EPA+DHA)含量均分别高于光滩养殖鱼,红树林下养殖的中华乌塘鳢肌肉脂肪酸组成比光滩养殖鱼具有更高的营养价值。 相似文献
4.
10月份,大西洋蛙Salmo salar流精雄鱼血清中11-氧睾酮(11-OT)的含量升高到23.2±7.12ng/ml,明显地较睾酮水平4.7±1.42ng/ml为高,并含有一定量的17α20β-双羟孕酮(17α20βP),为7.6±2.45ng/ml;而9月份血清中17α20βP的含量低于0.1ng/ml。 用部分纯化的大麻哈鱼Oncorhynchus keta的促性腺激素(GTH)0.1μg/ml和1μg/ml进行大西洋鲑成熟精巢的离体培育,持续6天,定时间隔作培养液取样,进行测定。 GTH明显地促进11-OT释放,并达到相当高的水平。培养液中睾酮和雄烯二酮的浓度仅略为升高;孕酮和17α-羟孕酮的浓度水平都较低,与对照组相差不大。在离体培育两天后,GTH诱发17α20βP迅速升高。培养液中11-OT、17α20βP、睾酮和雄烯二酮浓度的升高与GTH剂量大小无明显的依赖关系。 相似文献
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利用室内装置模拟的刺参养殖池塘上覆水,在温度为25℃,光照为(4000±200)lx条件下静态培养刚毛藻48 h,定时测定上覆水中总氮(TN)、氨态氮(NH_4~+-N)、硝态氮(NO_3~–-N)、亚硝态氮(NO_2~–-N)、总磷(TP)、活性磷(PO_4~(3–)-P)等营养盐含量,分析了氮磷营养盐含量的动态变化规律,探讨了刚毛藻生物量对沉积物-水界面营养盐含量变化的影响。结果表明,刚毛藻生物量对各营养盐含量的影响存在显著性差异(P0.05)。随着培养时间延长,上覆水中营养盐含量均呈现先增大后减小的趋势。上覆水中各营养盐含量在培养6～24 h时分别达到最大值,其中当刚毛藻生物量为0.5～4.5 g/L时,TN、NO_3~–-N、NO_2~–-N、NH_4~+-N、TP、PO_4~(3–)-P含量达到最大值。继续培养,上覆水中各营养盐的含量逐渐减小,其中生物量为8.5 g/L时刚毛藻对NO_3~–-N、NO_2~–-N的吸收效果最好;生物量为0.5 g/L时刚毛藻对NH_4~+-N、PO_4~(3–)-P吸收效果最好。因此,高生物量(8.5 g/L)刚毛藻可降低上覆水中NO_3~–-N、NO_2~–-N含量,但低生物量(0.5 g/L)刚毛藻能有效吸收上覆水中的NH_4~+-N、PO_4~(3–)-P。 相似文献
6.
为研究孕激素在大菱鲆(Scophthalmus maximus)精原细胞增殖到减数分裂过程中的作用,以6~22月龄的大菱鲆精巢为材料,通过组织学方法和定量amh、sycp3基因确定精原细胞增殖期和减数分裂期的大菱鲆精巢发育过程。通过酶联免疫吸附技术(ELISA)检测6~22月龄雄性大菱鲆血清中的孕酮(P4)和17α,20β,双羟孕酮(DHP)含量变化,利用q RT-PCR技术和原位杂交技术检测孕酮核受体(pgr)和膜受体(m PRα)在不同组织和不同发育时期的表达情况。结果表明孕激素在精原细胞增殖期高表达,开始出现初级精母细胞时降低,在精子细胞数量增加时表达量再次升高,在精子细胞变态形成精子时降低。pgr在减数分裂初期定位于精巢中的sertoli细胞,在精原细胞增殖至减数分裂期表达量逐渐增加,出现精子后显著降低;m PRα在精原细胞增殖和初级精母细胞增加时表达量都很低,在精子细胞不断增加时显著增加。推测在精原细胞增殖和减数分裂阶段孕激素可能主要通过调节pgr的表达量来促进精巢发育,而在减数分裂II期pgr和m PRα都发挥作用,在精子细胞变态成熟时,主要是m PRα发挥作用。 相似文献
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1α,2 5-双羟维生素 D3 [1 α,2 5(OH) 2 D3 ]作用于靶细胞后产生 2种不同的信号传导系统 :基因效应和非基因效应。前者是指 1α,2 5(OH) 2 D3 与维生素 D核受体 (n VDR)结合 ,n VDR再与视黄酸 X受体 (RXR)发生异二聚化反应 ,在转录因子 (TF)的作用下 ,促使靶基因转录。后者是指 1 α,2 5(OH) 2 D3 与维生素 D膜受体 (m VDR)结合 ,随之引发一系列信号传导 ,促使细胞膜上的 Ca2 -通道迅速打开。探讨 1α,2 5(OH) 2 D3 的作用机制有利于开发治疗维生素 D内分泌系统疾病的新药。本文就目前有关 1 α,2 5(OH) 2 D3 作用于靶细胞的机制的研究成果进行综述。 相似文献
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本文建立了半透膜渗透装置(semi-permeable membrane device,SPMD)富集-超声萃取-凝胶渗透色谱净化-气相色谱法测定沉积物间隙水中多氯联苯(PCBs)的方法。比较了有机溶剂透析法与超声萃取法从膜袋内提取PCBs的回收率,发现超声萃取法在节省时间和溶剂方面有明显优势。应用凝胶渗透色谱分离与净化SPMD提取物,收集11—17min的流出液能达到最佳分离效果。基于此方法测定了大连湾沉积物间隙水中自由溶解态PCBs的含量(C_(W-SPMD)),同时又分析了沉积物中PCBs的总量(C_(SED))、间隙水中PCBs的含量(有机碳含量校正法,C_(W-SED))和间隙水中PCBs的总含量(离心法,C_(PW))。结果表明,C_(PW)值显著高于C_(W-SED)和C_(W-SPMD)值。因此,考虑到生物可利用性,无论采用沉积物中或者间隙水中的PCBs总量进行污染物生态风险评价均会造成风险被高估,建议采用间隙水中可溶解态含量。 相似文献
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氨基脲(semicarbazide,SEM)作为新型环境污染物已在海洋、食品和人体尿液中检出,其对环境和生物体可能带来的影响越来越受到人们的关注。研究采用1、10、100、1 000μg/L的SEM急性暴露96h的成年雄性斑马鱼,对性腺指数、17β-雌二醇(E2)和睾酮(T)的含量、性激素合成酶以及HPG轴相关的基因相对表达量进行测定,探究SEM急性暴露对雄性斑马鱼的内分泌干扰效应。结果表明,低剂量1μg/LSEM急性暴露通过抑制下丘脑中HPG轴起始因子s型促性腺激素释放激素(sGnRH)sGnRHmRNA相对表达量,进一步抑制促卵泡激素(FSH)FSHβ、促黄体激素(LH)LHβ、细胞色素P450 19B (CYP19B) CYP19B基因相对表达量,中高剂量10、100、1 000μg/L的SEM急性暴露下调下丘脑sGnRHmRNA的表达却上调c型促性腺激素释放激素(cGnRH)cGnRH、CYP19B的表达;而不同浓度的SEM暴露均会下调精巢内3β-羟类固醇脱氢酶(3β-HSD) 3β-HSD、细胞色素P450 17(CYP17) CYP17、细胞色素P450 11A (CYP1... 相似文献
10.
贝藻混养生态系统模拟实验研究 总被引：2，自引：0，他引：2
2013年4~6月,在室内采用实验生态学的方法进行了海湾扇贝(Argopecten irradias)和孔石莼(Ulva pertusavar)4种配比模式的混养实验。各实验组扇贝密度均为48只/m3,孔石莼密度分别为55、121、255和338g/m3。每周采样测定水体中营养盐(NH4-N、NO3-N、NO2-N、PO4-P)的含量及养殖生物的生长情况。扇贝与孔石莼的混养实验结果表明,在养殖系统中引入孔石莼可以改善养殖环境,扇贝和孔石莼的适宜混合比例为1︰1(贝肉湿质量:藻类湿质量)能取得较好的生态效应。 相似文献
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The sex ratio in the catches of megrim (Lepidorhombus whiffiagonis, Walbaum) varied systematically with depth on three independent trawl survey series off the west coast of Ireland. Female megrim dominated the shallow catches, while males were more common in catches from deeper waters. The size difference between the sexes alone cannot explain this pattern because it remained evident when fish length was taken into account. Therefore size-specific habitat preferences or size-selective fishing mortality cannot fully explain the observed trend in the sex ratio of megrim. Female megrim grow to a larger size, at a faster rate than males and it is likely that their differences in habitat preferences are related to this. Shallower waters are warmer during the growing season and are likely to provide better conditions for fast growth. An understanding of the mechanisms behind these patterns is an important consideration in the management and conservation of this fish stock, which might be particularly vulnerable because the commercial landings are to a large extent dominated by female megrim. 相似文献
13.
摄食水平和性别对稀有鮈鲫生长和能量收支的影响 总被引：7，自引：0，他引：7
于1995年10月采集本所自繁有ju鲫（约1.03g/ind)，在30℃水温下进行摄食－生长实验，研究了从饥饿到饱食5个摄食水平对不同性别稀有ju鲫的生长和能量收支的影响，结果表明，鱼体干物和能量含量不受摄食率和性别的影响，随着摄食率的增加，雌鱼的湿重，干重和能量特定生长率均呈双对数增加，雄鱼湿重特定生长率呈双对数增加，而干物质和能量特定生长率呈指增加，雄鱼生长速度及摄食率低于雌鱼，随着摄食率的增加，食物能损失于粪便中的比例均呈上升趋势，损失于排泄物中的比例变化不大，呈下降趋势，用于代谢的比例呈下降趋势，用于生长的比例呈上升趋势，除饥饿组外，在各个摄食水平，雌鱼食物能用于代谢的比例较雄鱼低，而用于生长的比例较雄鱼高。 相似文献
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部分水生经济动物具有性别二态性，这种特性与养殖品质、商业价值相关。与哺乳动物不同，水生动物不具有明显的性征，在育种时难以识别亲本性别，会造成额外的劳动力和培育成本。该文主要围绕水生经济动物性别遗传基础及其鉴定方式，综述了水生经济动物的性别二态现象、常见的性别鉴定方式以及决定基因，以期为种质资源保护和良种选育提供理论参考。 相似文献
15.
Imposex was measured in the rock shell, Thais clavigera, from the coast of the Korean peninsula. Frequency of imposex was 0% at two reference sites, but at 47 out of 61 sites, frequency of imposex was recorded as 100%. The degree of imposex was relatively high at the sites near a harbor and a shipyard. Tributyltin (TBT) and triphenyltin (TPT) concentrations in T. clavigera ranged from 5 to 508 ng/g and from 3 to 2460 ng/g, respectively. A significant positive relationship was found between degree of imposex and organotin concentration, whereas a significant negative relationship was obtained between female-to-male sex ratio and the degree of imposex. During a field transplantation of T. clavigera from a pristine area to a port, TBT and TPT were accumulated in T. clavigera, and imposex was induced. T. clavigera shows considerable potential as a bioindicator species of the adverse effects of TBT and TPT contamination. 相似文献
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施氏獭蛤(Lutraria sieboldii)性腺发育和生殖周期的研究 总被引：1，自引：0，他引：1
采用组织学方法对湛江市遂溪县草潭镇施氏獭蛤的性腺发育和繁殖规律进行了研究。结果表明,施氏獭蛤的性腺发育以1年为1个周期,可分为增殖期、生长期、成熟期、排放期和休止期。雄性生殖细胞发生经历精原细胞、初级精母细胞、次级精母细胞、精子细胞和精子等时期,精原细胞具有A型和B型两种类型。施氏獭蛤卵子的发生可分为卵原细胞期、生长初期、生长中期、生长后期和成熟期。较晚期的卵母细胞和成熟卵子的核仁变成双质核仁。流沙港海区施氏獭蛤性腺指数峰值出现在1月,为3.47%;该贝的繁殖期为10月—次年4月,繁殖期水温为16.2—26.5℃。雌、雄性腺发育基本同步,雄性发育略快,雌雄比为2:1。 相似文献
17.
The occurrence of intersexuality in populations of the marine amphipod Echinogammarus marinus has been related to several causes, including anthropogenic contamination, microsporidian parasites and environmental sex determination (ESD). At the individual-level, the costs of intersexuality in E. marinus are reflected in reduced reproductive output of intersexes compared to normal specimens. The impacts of intersexuality and other reproductive disorders in nature will only be fully understood when individual-level effects are upscale to the population-level, which can be achieved through ecological models. The aim of the present work is to simulate the density variation of real populations of E. marinus with different intersexuality incidence, proportions of phenotypes and intersex female reproductive rates. To achieve that, we have incorporated empirical data obtained at the individual-level from three intersexed populations of E. marinus into a population dynamic model. The original model was calibrated and validated for a long-term stable population without intersexuality and sex ratio 1. In the present version, the model includes an extra population group, intersex females, but the total sum of flow rates from juveniles to adults was kept the same as in the original model to respect the previous validation. In these circumstances, results indicate that the male-biased population is very sensitive to intersexuality, even at low incidence levels, and exhibits significant density decrease if conditions do not change. On the contrary, the two populations with a preponderance of female-biased sex ratios, low or moderate intersexuality incidence (up to an average value of 9% of the population) and with intersex reproductive rates corresponding to 80% the value of normal specimens, exhibit long-term persistence.The model is highly sensitive to adult female parameters (e.g. mortality), indicating that small variations on its values can significantly change population responses.Overall the present results suggest that, in spite the costs of intersexuality in E. marinus, the temporal variation of intersexed populations depend on intersex incidence level, sex ratio fluctuations and reproductive output of intersexes. Simulations also suggest that other processes (e.g. mortality rates of normal females) may play important roles in the maintenance of populations with intersexuality. In the future, it will be crucial to improve and validate this type of models with long-term observations and monitoring of intersexed populations. 相似文献
18.
Knut-Erik Tollefsen Joris F. A. Meys Jorid Frydenlund Jrgen Stenersen 《Marine environmental research》2002,54(3-5)
Environmental chemicals may modulate the endocrine system through interaction with plasma sex steroid-binding proteins (SBP) and SBP-regulated processes. Some of these chemicals, which are known to interact with the estrogen receptor (ER), were found to bind competitively to the Atlantic salmon (Salmo salar) SBP and potentially disrupt the endocrine function of these proteins. Furthermore, both weakly acting (di-n-butyl phthalate) and potent estrogen mimics (ethynylestradiol), were able to induce a substantial up-regulation of circulating levels of SBP in vivo. Interestingly, modulation of SBP-levels was found to be a more sensitive endpoint than chemically induced interference with classical ER-mediated mechanisms for weakly acting estrogen mimics like di-(n-butyl) phthalate. Interference with the endocrine function of SBPs may thus introduce a novel mechanism for endocrine disruption, and give additional answers to the question why some weakly acting xenoestrogens are causing “estrogen-like” reproductive disturbances in developing males. 相似文献
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The impact of overfishing and El Niño on the condition factor and reproductive success of Peruvian hake, Merluccius gayi peruanus 总被引：1，自引：1，他引：0
Michael Balln Claudia Wosnitza-Mendo Renato Guevara-Carrasco Arnaud Bertrand 《Progress in Oceanography》2008,79(2-4):300
In this study we examine physiological responses of Peruvian hake (Merluccius gayi peruanus) to changes in their population structure and physical environment during the period 1971–2004. In particular, we assess the relative investment of energy in growth and/or reproduction of small (20–35 cm) and large (35–50 cm) hake. We calculated the (i) condition (Fulton’s K), (ii) gonad and (iii) gut fullness indices for 42,761 female hakes sampled from commercial landings; these indices indicate fish somatic, reproductive and feeding condition, respectively. Using Generalized Additive Models we then examined potential relationships between these indices and sea surface temperature anomalies and date. Drastic energy exhaustion and a decrease in female hake fecundity were observed during El Niño events. The long-term trend showed a general increase in condition factor and a decrease in gonad index for large hake between 1971 and 2004. Small hake exhibited a different trend with an increase in reproductive activity, which was accompanied by an earlier maturation. We hypothesise that the observed low investment of energy in reproduction by large female hake might be related to the lack of large males, due to a sex-selective fishery and the impact of El Niño. We suggest that fishing diminished hake reproductive capacity, modified the sex ratio in favour of females and increased population vulnerability to environmental stress, in particular to the El Niño. The impact of multidecadal variability and predators like the squid, Dosidicus gigas, remain unresolved until longer time series become available. 相似文献