共查询到20条相似文献，搜索用时 15 毫秒
1.
Wang Renxue Wu Xianhan Zhou Jing Zhang Shicui Ma Yingjie Wu Shangqin Shi Yingxian 《中国海洋湖沼学报》1991,9(1):88-93
Full maturation of goldfish oocyte was inducedin vitro by 17 α-hydroxy-20β-dihydroprogesterone. The oocyte maturation involves GV migration to the periphery of the oocyte and germinal
vesicle breakdown (GVBD). In the experiment, incubation duration for GVBD varied in different broods of oocytes. Generally,
if the duration for GVBD was shorter than 6 h, oocytes would have a better chance to survive after maturation and insemination.
The maturation of nucleus (GV) and cytoplasm are not synchronous. Cytoplasm maturation occurs several hs after GVBD. Oocytes
inseminated 8–9 h after GVBD have the highest fertilizing and hatching rate. Fertilized ova maturedin vitro can develop to sexually mature adults capable of reproduction.
Contribution No 1731 from the Institute of Oceanology, Academia Sinica. 相似文献
2.
The in vitro effects of steroids, human chorionic gonadotropin (HCG) and cyanoketone on germinal vesicle breakdown (GVBD)
of striped mullet (Mugil cephalus L.) oocytes were investigated. All concentrations of HCG (5,10,50 I.U./ml), progesterone and pregnenolone at the highest
concentrations(lug/ml) were moderately effective in inducing GVBD, whereas 17β-estrodiol, cortisol, testosterone, 11β-hydroxyandrostenedione
and 11-ketotestosterone did not stimulate GVBD. 17α, 20βdihydroxy-4-pregnen-3-one (17α, 20βdiOHprog) and deoxycorticosterone
(DOC) were the most potent steroids in stimulating final oocyte maturation. The results indicate that C21 hydroxylated steroids
are potent inducers of final maturation in mullet. Further, co-incubations with 17β-estradiol, cortisol and testosterone did
not alter the maturation-inducing effects of HCG or 17α,20βdiOHprog. Cyanoketone, a blocker of 3βHSD activity, was only partially
effective in blocking GVBD induced by HCG. This suggests that Δ5 (pregnenolone derived) and Δ4 steroids may be involved in
final oocyte maturation in this species. 相似文献
3.
WANG Qi IKEGAME Keita TAKAHASHI Koretaro XUE Changhu ZHANG Weinong WANG Hongxun HOU Wenfu WANG Yuming 《中国海洋大学学报(英文版)》2013,12(3):413-417
Lipids were extracted from organs of the starfish Asterias amurensis associated with different treatments(raw-control,boiling and heating),and then analyzed for lipid content,lipid oxidation index,lipid classes and fatty acid composition.Results showed that boiling softened the hard starfish shells,thus facilitating the collection of starfish organs.As compared with raw organs,the boiled organs had lower water content and higher lipid content,possibly due to the loss of water-holding capacity caused by protein denaturation.Both boiling and heating increased the peroxide value(PV),thiobarbituric acid(TBA) value and carbon value(CV) of lipids.Despite slight increases in the content of complex lipids,associated lipid composition had no substantial variations upon boiling and heating.For simple lipids,the content of 1,2-diglyceride decreased in boiled and heated organs,with free fatty acids observed on thin layer chromatography(TLC).However,neither boiling nor heating significantly changed the fatty acid compositions of simple or complex lipids in starfish organs,suggesting that these two treatments had no significant effects on complex lipids in starfish organs.Together,our results indicated that boiling of starfish soon after capture facilitated the handling and extraction of useful complex lipids consisting of abundant glucosylceramide and eicosapentaenoic acid(EPA)-bounded phospholipids. 相似文献
4.
Starfish oocytes with intact germinal vesicles (GVs) were cut along desired planes with glass needles or ligated using silk
thread loops into two parts and allowed to mature in vitro, and inseminated. The experimental results showed that (1) only
the parts with GVs or partial GV contents (PGVCs) cleaved, those without any GV materials did not; but nucleated and non-nucleated
fragments cut from mature eggs were able to divide; (2) the development of animal parts of oocytes containing GVs or PGVCs
was like that of animal fragments of matured oocytes with female pronuclei; most of them gave rise to permanent blastulae,
and just a few formed ectodermal vesicles with a little primary mesenchyme; (3) a large part of vegetal fragments with GVs
or PGVCs, and the vegetal parts of mature eggs without female pronuclei developed into small but normal embryos; (4) the fragments
containing GVs or PGVCs obtained from the oocytes along a plane parallel to the animal-vegetal (A-V) axis developed as normally
as the halves (with or without female pronuclei) severed from mature eggs along the same axis. Based on the data above, it
was concluded that (1) the non-chromatin materials in the oocyte GVs are indispensable for successful fertilization and cleavage
of starfish eggs; (2) some factor (s) located asymmetrically in the vegetal hemispheres of starfish oocytes is (are) responsible
for formation of the archenteron and primary mesenchyme. It is evident from the above findings that the oocyte cytoplasm of
the starfish had already regionalized before the GV break-down.
Contribution No. 1722 from the Institute of Oceanology, Academia Sinica 相似文献
5.
Tingjun Fan Xianyuan Fan Yutang Du Wenjie Sun Shaofeng Zhang Jiaxin Li 《中国海洋大学学报(英文版)》2011,10(3):255-262
To understand the mechanisms of starfish regeneration, the arms of adult starfish Asterias rollestoni Bell were amputated and their regeneration patterns and cellular mechanisms were studied. It was found that cells in the outer epidermis and inner parietal peritoneum near the end of the stump began to dedifferentiate 4 d after amputation. The dedifferentiated cells in the outer epidermis proliferated,migrated to the wound site and formed a thickened pre-epidermis which would then re-differentiate gradually... 相似文献
6.
Serotonin (5-HT) has been found to stimulate meiotic maturation of oocytes in many molluscs. During maturation, several signaling pathways are involved, especially the phosphatidylinositol and cAMP pathways. In order to examine the possible role of the phosphatidylinositol signaling pathway in regulating oocyte maturation in Mercenaria mercenaria, the effects of the activator/inhibitor of phospholipase (PLC) and protein kinase C (PKC) on serotonin-induced maturation were studied. Results show that high-concentrations of neomycin (inhibitor of PLC) blocked oocyte maturation, while 9, 10-dimethyl-1, 2-benzanthracene (DMBA, activator of PLC) promoted oocyte maturation in the presence of serotonin. It was also found that in the presence of serotonin, phorbol 12-myristate 13-acetate (PMA, activator of PKC) inhibited oocyte maturation, while sphingosine (inhibitor of PKC) stimulated oocyte maturation. These results indicate that serotonin-induced oocyte maturation requires the activation of the phosphatidylinositol pathway. Decrease of PLC inhibited serotonin-induced oocyte maturation, whereas a decrease of PKC stimulated the maturation. Thus, our study indicates that serotonin promotes maturation of M. mercenaria oocytes through PLC stimulated increase in calcium ion concentration via inositol-1, 4, 5-trisphosphate (IP3) but not PKC. 相似文献
7.
8.
《中国海洋大学学报(英文版)》2015,(5)
Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail(Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Fishing induces evolutionary effects on the fish's biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection usually affect the fish's life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the changes in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size exhibited similar evolutionary trend tendency under long-term fishing. The time-dependent probability of significance trend showed a gradual growth and tended to be stable. Therefore, the direction of fishing-induced evolution and successful management of fish species require considerable attention to contribute to sustainable fisheries in China. 相似文献
9.
KONG Lingfeng WANG Zhaoping YU Ruihai LI Qi WANG Rucai 《中国海洋大学学报(英文版)》2007,6(4):383-386
The glycogen content and the activities of two key enzymes in glycogen metabolism, glycogen phosphorylase and gly- cogen synthetase, in the gonad of diploid and triploid Pacific oysters (Crassostrea gigas) were compared during maturation. The glycogen content in the gonad of diploids decreased with gametogenesis (by 85.7%), but the glycogen content in the gonad of trip- loids did not vary significantly. Activity of glycogen phosphorylase (GP) in the gonad of diploids decreased with gametogenesis (by 55.5%), while GP activity of triploids did not vary significantly during maturation. Activity of glycogen synthetase (GS) in the gonad of diploids increased slightly with gametogenesis, reaching a peak in June. Activity of GS declined sharply from June to July, which might be due to gonad spawning. GS activity of triploid oysters in spawning time (July and August) was significantly higher than that in other months, which might be explained with a ‘compensating’ mechanism for the higher glycogen content in triploids. 相似文献
10.
Pen a 1 is a major shrimp allergen that induces an allergy. The aim of this study is to assess the effect of simulated gastrointestinal
fluids on the allergenicity of Pen a 1. Purified Pen a 1 from shrimp (Penaeus vannamei) was subjected to digestion in SGF (simulated gastric fluid) and SIF (simulated intestinal fluid) for a set time. The allergenicity
of digestive Pen a 1 was analyzed by immunoblotting and Ci-ELISA, using pool sera from patients with shrimp specific IgE.
The results showed that Pen a 1 exhibited a decrease in allergenicity with increasing digestion time in the SGF and SIF. However,
Pen a l exhibited strong resistance to digestive fluids, and all yielded fragments (33 kD, 23 kD, and 14 kD) showed allergic
activity. Therefore, anti-digestion may be an important factor for Pen a 1 to induce an allergy. 相似文献
11.
对应用单边眼柄切除术促进斑节对虾雌虾卵巢成熟的技术和由此产生的某些现象,提出单边眼柄切除术、催熟的环境条件、蜕壳、再交配、人工精荚移植、早产和无节幼体质量及其影响因素等七个方面的问题进行讨论。 相似文献
12.
Localization of a putative epiboly-determining factor in oocytes of the goldfish (Carassius auratus)
It is unknown whether cytoplasmic determinants in goldfish eggs are asymetrically localized before maturation. In this study
fully grown goldfish oocytes with intact germinal vesiles (GVs) were ligated with baby hair loops along desired planes into
two parts, matured in vitro, and inseminated. Embryos developed from the animal halves with GV of oocytes ligated along the
equator were unable to undergo epiboly, while those developed from the GV-containing parts of oocytes ligated along the animal-vegetal
axis were able to. Also, embryos developed from the animal halves obtained from fertilized eggs could undergo epiboly. From
these results, it was postulated that the goldfish's premature oocyte possessed a putative factor in the vegetal hemisphere
which was responsible for epiboly of the embryonic cells.
This work was supported by the NSFC and the “Climb Plan B” (PD-B6-1-1) of the Chinese Commission of Science and Technology.
Contribution No. 2915 from the Institute of Oceanology, Chinese Academy of Sciences. 相似文献
13.
1 INTRODUCTION Ovarian development of female crustaceans is under the direct regulations of two neurohormones: gonad-inhibiting hormone (GIH) secreted by optic ganglia and gonad-stimulating hormone (GSH) se- creted by brain and thoracic ganglia (Fingerman… 相似文献
14.
“夜间经济”蕴含巨大的消费潜能和市场空间,夜间经济集聚区作为其载体,其准确识别、合理分类和科学布局是发展夜间经济的切入点和主要抓手,更是夜间经济可持续发展的保障。本文在“点轴发育、定量识别”的认知框架下,在定量表达夜间经济活力测度的基础上,利用焦点统计和ISO聚类分析方法提取和识别夜间经济集聚中心和集聚区,并根据区位熵及其变异系数对识别结果进行类型划分,克服了目前夜间经济实践中存在的集聚区范围划定主观随意、类型标准不一的问题,为夜间经济定量化研究开辟了新的思路。研究表明：① 相较于DMPS/OLS及NPP-VIIRS等夜光遥感数据,Luojia1-01数据的空间分辨率高,溢出效应低,更适合于“夜间经济区”这种小尺度的精细化研究。② 夜间灯光和兴趣点数据是夜间社会活力和功能活力的良好表征,其综合影响可通过夜间经济活力测度来定量表达;③ 上海推出的12个地标性夜生活集聚区中,有11个被识别,识别率达91.7%;④ 根据集聚区的功能结构差异,可将其划分为非平衡发展-起步型、平衡发展-起步型、非平衡发展-成熟型、平衡发展-成熟型4种类型,该分类方式具有普适性;⑤ 在起步阶段,上海中心城区夜间经济集聚区主导功能为购物、餐饮;在成熟阶段,其特色发展方向为住宿、科教文化和体育休闲功能。四大集聚区类型在空间分布上形成明显的圈层结构。 相似文献
15.
Son Jin-Dam 《世界地质(英文版)》2000,3(2)
The Yuchon Group in the Late Cretaceous of Haenam and Mokpo area on the southwest coast of Korea peninsula can be divided into two Formations: (1) the intermediate volcanic Formation (Hwawon Formation), about 500m thick, (2)the acidic volcanic Formation (Hwangsan Formation), about 400m thick in ascending order.The former comprises intermediate volcaniclastics interlayered with volcanic rocks, and red mudrock and tuffaceous sandstone indicating fluvial deposits. The latter is subdivided into the upper part (Hwangsan Tuff Member) consisting of subaerial pyroclastics and intercalated rhyolites, and the lower part (Byeongonri Member) including subaqueous volcaniclastics, lake deltaic sandstone and gravelstone, lacustrine black shale and limestone and chert, and lake turbidite sandstone.The Late Cretaceous basin including Haenam subbasin in southwest Korea was largely formed of extensional nonmarine depressions (volcano- tectonic) bounded by NE- SW sinistral fault system.The thermal maturation based on geochemical and mineralogical studies for the black shales and tuffaceous sandstones reached the late stage of oil generation zone or gas generation stage. It seems that black shales and limestones are fairly good as source rock. The porosity of potential reservoir sandstone and tuff ranges from 5 % to 11%, but their permeability except the fractured rocks is very low ( ＜1md) because of fine pore throats reduced by diagenetic cementation of tuffaceous sandstones. Numerous potential traps might have been formed by the later folding and faulting along with lateral facies change and abundant mudrocks and volcaniclastics should make excellent seals. 相似文献
16.
The limited knowledge about the relationships between environmental factors and the maturation and reproductive seasonality of nemerteans is mostly obtained from field studies, and in many cases is conjectural. Few species have been studied under well-controlled laboratory conditions. In this work, the effects of temperature and photoperiod on gonad development and spawning of Cephalothrix hongkongiensis were observed by rearing worms under different temperatures and photoperiods. Worms reared at 4℃ and 6℃ showed no growth or gonadal development, and all died within 109 days. At 8℃ and 12℃, gonads could be seen from 90 days to the termination of the 360-day experiment, but no spawning was observed. Worms maintained at 16, 24, and 28℃ showed both gonadal development and spawning, and matured faster at higher temperatures. Under a fixed temperature(16℃), photoperiod did not have any significant impact on maturation and spawning. It is likely that temperature plays a major role in regulating the maturation and reproductive cycle of C. hongkongiensis. 相似文献
17.
珠母贝、亲贝人工促熟培育与催产的研究 总被引：2，自引：0，他引：2
从23 ~24℃开始,每4~5d升高水温1℃,终至26~27℃,并用亚心形扁藻(Platymonassubcordiformis)、三角褐指藻(Phaeodactylartriconrutum)及辅助饲料投喂培育,促进珠母贝[Pinctadamargaritifera(Linne) ]亲贝性腺发育成熟。用阴干刺激、异性产物刺激及浓扁藻液结合诱导,催产率达100%。 相似文献
18.
Son Jin - Dam 《东北亚地学研究》2000,(2)
IntroductionThe Haenam Depression filled with the LateCretaceous sediments and volcanics lies to the southwestern coast of Korea peninsula. The Cretaceousstrata (Yucheon Group) cover an area of ca. 200km2in the Haenam and Mokpo area. Regional geologicalsu… 相似文献
19.
We conducted a phenological evaluation of Sargassum thunbergii, a common algal species, along the coast of Lidao Bay, Rongcheng, China. The local S. thunbergii population entered a maturation period from early June to mid-August, when seawater temperature was 14.4 to 25.1°C. Our results suggest an increase in temperature and day length during this period initiated thalli maturation. Inhabitants of the low tidal zone had higher thalli length and biomass compared with those from the mid-and high tidal zones. We observed a switch in the length frequency distribution and contribution of length classes to biomass between the small (<20 cm) and long (20–79.9 cm) length classes at the time of thallus maturity. This suggests there is a trade-offbetween sexual reproduction and vegetative regeneration. 相似文献
20.
应用因子分析法研究密鲴繁殖力与诸因素的关系。六个变量是体长、体重、成熟系数、绝对怀卵量和相对怀卵量。29个样本、经正交变换得到3个因子:绝对繁殖因子、相对繁殖因子和成熟因子。 相似文献