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1.
以１０＾－６Ｍ和１０＾－５Ｍ的视黄酸体外处理草鱼（Ｃｔｅｎｏｐｈａｒｙｎｇｏｄｏｎ ｉｄｅｌｌｕｓ）早期胚胎,结果发现其影响了胚胎的形态发育,影响其中轴器官的形成和神经系统的分化,使胚胎前部结构全部或部分缺失,由此诱导的神经器官,如眼、听囊、嗅囊等缺失或不分化,胚胎的尾部缩短;同时也减少了色素细胞的形成。并且这种畸形程度随着处理浓度加大,时间加长而加剧。但是原肠中期以后处理的胚胎,神经系统发育基本正常,因此说明视黄酸并不抑制原肠作用和随后的神经诱导。它可能是通过抑制某些基因的表达而影响神经外胚层的区域性分化。 相似文献
2.
苏氏圆腹胚胎发育的初步观察 总被引：1，自引：0，他引：1
观察两批苏氏圆腹受精卵的胚胎发育,描述并记录胚胎发育各期的形态特征及发育时间。结果表明:苏氏圆腹成熟卵呈圆球形,淡黄色,富有光泽,卵黄分布均匀,相对密度略大于水,卵径0.93～1.11 mm,平均0.98±0.19 mm。受精卵吸水后呈微黏性,属黏性卵,卵膜略膨胀,卵径0.99～1.15 mm,平均1.08±0.27 mm。苏氏圆腹胚胎发育属于盘状卵裂,与其他淡水硬骨鱼类基本相似。其发育过程可分为:受精卵、卵裂期、囊胚期、原肠期、神经胚期、器官分化期、出膜期和初孵仔鱼。在水温26±1℃的条件下,苏氏圆腹胚胎孵化历时24 h 45 min,总积温640.90 h.℃。初孵仔鱼体全长3.20～3.60 mm。 相似文献
3.
用冷热休克诱导四倍体近江牡蛎 总被引：1，自引：0，他引：1
当近江牡蛎授精卵发育至第一次卵裂前3min或个别受精卵开始出现第一次卵裂时,分别用热体克(37℃,39℃,41℃)和冷休克(8℃,10℃,12℃)处理3min诱导四倍体。测定39℃热休克组胚胎早期的四倍体诱导率为28％,10℃冷休克组胚胎早期的四倍体诱导率为30%。温度过高(如42℃以上)可导致卵的高死亡率。 相似文献
4.
波纹龙虾胚胎的离体培养及发育观察 总被引：1，自引：1，他引：0
对波纹龙虾不同发育时期的胚胎进行离体培养和显微观察。结果表明,初始培育的离体胚胎愈接近孵化期,其孵化率愈高(最高达80.0%);波纹龙虾胚胎发育经历受精卵、卵裂期、囊胚期、原肠期、中眼色素形成期、复眼色素形成期、心跳期、破膜前期和出膜期;胚胎在发育过程中颜色变化:橙红→深橙红→砖红→灰白→接近透明。 相似文献
5.
【目的】研究弓背青鳉(Oryziascurvinotus)胚胎各阶段的发育特点,观察其自发荧光。【方法】使用正置荧光显微镜对弓背青鳉受精到孵化出膜过程进行连续观察。【结果】弓背青鳉胚胎发育历时10～12d,发育过程分为受精卵激活期、受精卵胚盘形成期、卵裂期、囊胚期、原肠胚期、神经胚期、器官形成期及孵化出膜期共8个时期;根据各时期胚盘形成、体节数量、器官发生、胚体大小和运动等特征的变化,进一步细分为35个阶段。其自发荧光主要开始出现于12肌节期,由虹彩细胞团内的物质在激发光下产生,主要分布于脑与脊索背面的皮肤表层。 相似文献
6.
黑斑蛙(Rana nigromaculata)早期发育过程中乳酸脱氢酶同工酶 总被引：3，自引：1，他引：2
用垂直平板聚丙烯酸胺凝胶电泳技术对黑斑蛙早期胚胎发育过程中乳酸脱氢酶（LDH）同工酶进行研究。结果表明,黑斑蛙胚胎各个不同发育时期LDH同工酶谱有很大差异：LDH1在整个胚胎发育过程中均处于活化状态,LDH2、LDH4在原肠中期开始出现,LDH3在尾芽期开始出现。从尾芽期到尾血循环期只出现LDH－1、－2、－3和-4四条酶带,但不同时期各种同工酶的表达活性不同。 相似文献
7.
《广东海洋大学学报》2020,(2)
【目的】研究JAK3抑制剂对珍珠囊发育及移植免疫反应的影响。【方法】以马氏珠母贝(Pinctada fucata martensii)为材料,植核前用JAK3抑制剂处理细胞小片和珠核,植核后18 d和30 d取珍珠囊,用石蜡切片技术和H.E.染色法(Hematoxylin-eosin Staining)观察JAK3抑制剂对珍珠囊发育的影响,利用荧光定量技术检测植核后不同时间(6、12、24 h和3、6、12、18、30 d)免疫相关基因NF-kappaB(Nuclear factor kappa B)、IkappaK(I-kappaB kinase)和炎性诱导因子IL-17(Interleukin 17)的表达变化。【结果】植核后18 d和30 d,与对照组相比,JAK3抑制剂对珍珠囊的发育没有显著影响(P> 0.05)。荧光定量结果显示,植核后6 h和12 h,JAK3抑制剂可以显著性抑制IL-17的表达,植核后6、3、6、12 d,JAK3抑制剂可以显著性抑制NF-kappaB的表达,植核后3、6 d,JAK3抑制剂可以显著性抑制IkappaK的表达(P <0.05)。【结论】JAK3抑制剂对马氏珠母贝免疫基因表达有明显的抑制作用,可以有效调控珍珠贝植核后的移植免疫,而对珍珠囊发育的影响不明显。 相似文献
8.
《广东海洋大学学报》2021,(4)
【目的】研究海带岩藻多糖(Fucoidan)对Aβ25-35(Amyloidβ)诱导原代皮层神经突起萎缩和神经元凋亡的抑制作用。【方法】以Aβ25-35诱导的人神经母细胞瘤细胞(SH-SY5Y)和原代小鼠皮层神经元损伤为模型,采用CCK8法测定细胞存活率,免疫细胞化学法测定岩藻多糖对神经突起再生和神经元的保护作用。【结果】CCK8结果表明,岩藻多糖在0.1～1 000μg/m L时对SH-SY5Y细胞无明显毒性作用(P 0.05),在10～1 000μg/m L时可显著降低Aβ25-35诱导的SH-SY5Y细胞凋亡(P0.05),且呈现浓度依赖性;对该结果在原代小鼠皮层神经元上进行验证,发现岩藻多糖在0.1～1.0 mg/m L浓度时显著降低Aβ25-35诱导的神经元凋亡(P 0.01),同时极显著抑制Aβ25-35造成的神经突起萎缩并促进突起再伸长(P 0.001)。【结论】海带岩藻多糖可显著抑制Aβ25-35诱导的神经突起萎缩和神经元凋亡,促进突起再生,提示其可作为阿尔茨海默病药物开发的先导化合物。 相似文献
9.
盐度对管角螺胚胎发育的影响 总被引：1，自引：1，他引：1
在水温25.5~29.2℃的条件下,设11个盐度梯度对管角螺[Hemifusus tuba(Gmelin)]的胚胎发育进行了观察和研究。结果显示:管角螺胚胎发育的适宜盐度范围为22~35,最适盐度范围为25~31;在适宜的盐度范围内,7~9 d发育的胚胎能完全消耗卵囊内的败育卵变为自身发育的营养物质,13~15 d形成稚螺雏形,31~34 d胚胎完成发育从卵囊内爬出;适宜盐度范围内各盐度对正常卵发育数量、孵化率无显著影响。低于其适宜盐度范围,胚胎发育在初始阶段便受抑制,盐度为16~19只有部分正常卵发育,需34~36 d才完成胚胎发育;高于适宜盐度范围的38、41两组,在6 d内对胚胎发育无影响,但6 d后影响显著。低盐度对胚胎发育影响较高盐度更为明显。 相似文献
10.
用垂直平板聚丙烯酰胺凝胶电泳技术对黑斑蛙早期胚胎发育过程中乳酸脱氢酶（ＬＤＨ）同工酶进行研究,结果表明,墨斑蛙胚胎各个不同发育时期ＬＤＨ同工酶谱有很大差异;ＬＤＨ１在整个胚胎发育过程中均处于活化状态,ＬＤＨ２、ＬＤＨ４在原肠中期开始ＬＤＨ３在尾芽期开始出现,从尾芽期到尾血循环期只出现ＬＤＨ－１、－２、－３和－４四条酶带,但不同时期各种同工酶的表达活性不同。 相似文献
11.
湿地植物香蒲光合特性及其影响因素分析 总被引：1，自引：0，他引：1
李林锋 《广东海洋大学学报》2009,29(1)
以湿地植物香蒲为材料,在水平潜流人工湿地处理单元中,采用便携式LI-6400光合作用测定仪测定其成熟叶片净光合速率(Pn)日变化,研究其光合生理生态特性。结果表明:香蒲叶片净光合速率(Pn)日变化呈双峰曲线,主峰(22.0μmol.m-2.s-1)出现在9:00左右,次峰(16.9μmol.m-2.s-1)出现在15:00,光合"午休"现象明显,且非气孔限制是产生光合"午休"的主要原因。用逐步多元回归方法得到净光合速率日变化与主要生理生态因子的回归方程为:yPn=0.7692+29.7059 xGs-0.7689xTr+0.014 2 xPAR(复相关系数0.9563,显著水平P=0.0001;叶片净光合速率Pn,μmol.m-2.s-1;气孔导度Gs,mol.m-2.s-1;蒸腾速率Tr,mmol.m-2.s-1;光合有效辐射PAR,μmol.m-2.s-1)。偏相关分析和通径分析的结果表明Gs、Tr和PAR与Pn的日变化显著相关,是影响香蒲Pn的主要因子,影响大小的顺序为:Gs>PAR>Tr。香蒲叶片Pn-PAR的响应曲线方程为yPn=-5×10-6 xPAR 2+0.0207 xPAR-1.3728(相关系数0.9935,显著水平p=0.000 1),光补偿点、光饱和点和表观量子效率分别为32.9μmol.m-2.s-1、147 6μmol.m-2.s-1、0.023 3 mol.mol-1;Pn-CO2的响应曲线方程为yPn=-2×10-5 w(CO2)2+0.054 9 w(CO2)-1.44 4(相关系数0.9694,显著水平p=0.000 1;w(CO2)单位为μmol.mol-1),CO2补偿点、CO2饱和点和羧化效率分别为23.7μmol.mol-1、621.4μmol.mol-1和0.0768 mol.m-2.s-1。 相似文献
12.
改进重铬酸钾法快速测定水样CODcr 总被引：7，自引：0，他引：7
研究了用硫酸锰代替贵金属硫酸银作催化剂,在H2SO4-H3PO4介质中,重铬酸钾回流法测定水样中CODcr的新方法.通过实验,确定了最佳测定条件:MnSO4浓度为1×10-1mol.L-1;混酸溶液(H2SO4:H3PO4)=5:1(体积比);回流时间10min.并与标准方法进行了对比,准确度和精密度同标准法相近,大大节约了分析时间. 相似文献
13.
The DF1-1 submarine pipeline was investigated using a dual-frequency side-scan sonar and a swath sounder system. More than
a hundred scour pits under the pipeline were found, most of which have caused the span of the pipeline to increase and threatened
its safety. The maximum allowable free span length (MAFSL) of the pipeline was determined through the limitations regarding
maximum allowable stress under static or quasi-static loads and the onset of Vortex Induced Vibrations (VIV) under different
hydrodynamic actions. The results show that the MAFSL under static conditions is 56 m. However, the MAFSLs are 30 m and 20
m under ordinary weather conditions and hurricane-induced currents for the 100-year return period, respectively, to avoid
VIV as calculated by using the highest safety class factor. It is suggested that spanning pipelines longer than 20 m should
be supported. Additionally, eight successive spans which may also threaten the pipeline were proposed. The most hazardous
scour pits are along the pipeline section from KP42 to KP51. 相似文献
14.
《山地科学学报》2021,(6)
Strong wind events frequently result in creating large areas of windthrow, which causes abrupt environmental changes. Bare soil surfaces within pits and root plates potentially expose soil to erosion. Absence of forest may alter the dynamics of water circulation. In this study we attempt to answer the question of whether extensive windthrows influence the magnitude of geomorphic processes in 6 small second-to third-order catchments with area ranging from 0.09 km2 to 0.8 km2. Three of the catchments were significantly affected by a windthrow which occurred in December 2013 in the Polish part of the Tatra Mountains, and the other three catchments were mostly forested and served as control catchments. We mapped the pits created by the windthrow and the linear scars created by salvage logging operations in search of any signs of erosion within them. We also mapped all post-windthrow landslides created in the windthrow-affected catchments. The impact of the windthrow on the fluvial system was investigated by measuring a set of channel characteristics and determining bedload transport intensity using painted tracers in all the windthrow-affected and control catchments. Both pits and linear scars created by harvesting tend to become overgrown by vegetation in the first several years after the windthrow. The only signs of erosion were observed in 10% of the pits located on convergent slopes. During the period from the windthrow event in 2013 until 2019, 5 very small(total area 100 m2) shallow landslides were created. The mean distance of bedload transport was similar(t-test, p=0.05) in most of the windthrow-affected and control catchments. The mapping of channels revealed many cases of root plates fallen into a channel and pits created near a channel. A significant amount of woody debris delivered into the channels influenced the activity of fluvial processes by creating alternating zones of erosion and accumulation. 相似文献
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16.
The developmental fate of the pronuclei in recombined embryos obtained by transplanting the donor nuclei into the non-enucleated eggs remains controversial in the case of fish.In the present study,the nuclei from the loach blastulae were transplanted into non-enucleated zebrafish eggs,the resulting 9 inter-family nuclear transplant embryos developed to larval stages,Although the development timing of the nuclear transplants resembled that of zebrafish,chromosome examination revealed that most of the recombined embryos were diploids with karyotype characteristic of loach,which was also proved by RAPD analysis.Moreover,3 out of the 9 larval fish formed barb rudiments specific to loach.It was therefore concluded that the nuclear transplant larval fish were inter-family nucleo-cytoplasmic hybrids;and that only the donor nuclei were involved in the development of the nuclear transplant embryos,while the pronuclei in the non-enucleated eggs were likely automatically eliminated during the development. 相似文献
17.
Fertilized goldfish eggs were dechorionated with a pair of forceps and were cut off along or a little above the equator into
animal and vegetative parts at desired stages with a glass needle or ligated into two connected fragments before cleavage
with baby hair loop. Some of the ligated eggs were detached by further fastening soon after ligation, and some released later
at different stages (2-cell, 16-cell, 128-cell, 512-cell, mid-blastula) to let the organ-forming substance (OFS) enter the
blastoderm. The cholinesterase (ChE) in the resulting embryos was assayed. The results are as follows. 1. All the 142 embryos
developed from the animal hemispheres cut off or ligated off before cleavage gave rise to hyperblastula in which no ChE activity
was observed. 2. All 50 embryos obtained from animal halves isolated at the 8-cell stage produced ChE. 3. Embryos developed
from the eggs released before the 512-cell stage formed ChE, but the later the releasing of the hair knots, the smaller the
number of ChE-producing embryos. 4. After the 512-cell stage (excluding this stage), neither ChE nor tissue differentiation
occurred in the embryos developed from the unfastened eggs though their OFS flow was set free. Since ChE is thought to be
a muscle-specific enzyme in the early developmental stage, it is concluded that the OFS in goldfish egg appears to be indispensable
for the establishment of the mesoderm.
Contribution No. 1507 from the Institute of Oceanology, Academia Sinica 相似文献
18.
As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP),diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP,DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of 1-1. diversicolor supertexta can be used to indicate toxicity of the PAEs. 相似文献
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20.
Effects of base analogues 5-bromouracil and 6-aminopurine on development of zebrafish Danio Rerio 总被引：1，自引：0，他引：1
Zebrafish （Danio rerio） genetic screens allow isolation of a wide array of problems in vertebrate biology. The effects of base analogues 5-bromouracil and 6-aminopurine on the development of zebrafish embryos are reported for the first time in this study. The early development of the zebrafish embryos was little affected by 5-bromouracil and 6-aminopurine, while the late development （organogenesis） was significantly impaired. Embryos exposed to 5-bromouracil mainly showed curled tail, wavy body, golden pigmentation and the mouth with protruding lower jaw. 6-aminopurine-treated embryos had defective anterior structures, curled tails and wavy body. RAPD analysis showed that the majority of 5-bromouracil-and 6-aminopurine-treated larvae and fish shared banding patterns in common with the control, suggesting that most mutagenesis induced by these agents are point mutations. However, some fish derived from 5-bromouracil-treated embryos had golden（gol） pigmentation; and RAPD analysis revealed that their band patterns differed from those of the control.Possibly, 5-bromouracil can occasionally cause relatively extensive changes in the fish genome. The results of this study may provide valuable help for detailed studies of mutagenesis. 相似文献