共查询到20条相似文献，搜索用时 46 毫秒
2.
锯缘青蟹蜕皮抑制激素cDNA的分子克隆及其表达分析 总被引：5，自引：1，他引：5
根据近缘种类同源序列设计简并引物,采用逆转录聚合酶链式反应(RT—PCR)技术,首次扩增获得锯缘青蟹(Scylla serrata)眼柄组织中编码蜕皮抑制激素(MIH)成熟肽全长cDNA序列及部分信号肽序列。将该序列克隆到pUCm—T载体上进行序列测定。结果表明,编码锯缘青蟹MIH成熟肽的cDNA由234个碱基组成,由此推测MIH成熟肽含78个氨基酸残基。该序列不仅与其它短尾类甲壳动物的MIH氨基酸序列具有高度的同源性(79％～9l％),还与该激素同一家族的性腺抑制激素、大颚器抑制激素的氨基酸序列具有较高的相似性。RNA斑点杂交结果显示,MIH基因在眼柄神经节及脑组织中均有表达,而在肌肉、中肠腺中不表达。 相似文献
3.
应用抑制性差减杂交技术构建了黄鳝(Monopterus albus)Ⅳ期卵巢和间期性腺的差减cDNA文库.正向差减杂交以间期性腺为试验方,Ⅳ期卵巢为驱动方;反向差减杂交以Ⅳ期卵巢为试验方,间期性腺为驱动方.将获得的差减cDNA片段连接质粒载体,然后转化大肠杆菌DH5α,最后获得的正、反向差减文库分别含461、678个重组子.经PCR扩增鉴定插入片段范嗣为200～2000 bp.随机选取正、反文库共100个阳性克隆测序分析,得到90个有效基因片段,与GenBank进行BLASTx和BLASTn同源比对.进一步从文库中选取2个基因用于半定量RT-PCR,对文库质量进行验证.结果表明,所建文库能够达到富集这两期性腺差异表达基因的目的.黄鳝性腺差减文库的构建,为进一步分离、鉴定黄鳝性腺发育和性逆转的相关基因奠定了基础. 相似文献
4.
锯缘青蟹(俗称黄格蟹)是畅销国内外市场的高档水产品之一.自2002年起,上虞市渔民在海涂九六丘北塘外陆基围塘养殖锯缘青蟹,至今养殖面积已达4000余亩.2006年市近海特种水产养殖基地在陆基围塘锯缘青蟹养殖中采用生态养殖技术,当年养殖的锯缘青蟹平均规格达265克以上,其中300克以上的锯缘青蟹占30%,该锯缘青蟹品质好,肉质鲜美,深受广大消费者所喜爱. 相似文献
5.
6.
7.
锯缘青蟹、Scylla serrata(Forskal)是我国近几年开发新的增养殖品种。近几年,浙江省温岭市水产技术推广站周友富工程师主持“锯缘青蟹生产性育苗技术研究”课题,经过8年的科学探索性攻关试验,终于突破青蟹生产性育苗关。今年通过省级专家鉴 相似文献
9.
近几年来,锯缘青蟹人工育苗技术虽然得以逐步推广,但提高锯缘青蟹人工育苗的成活率和出苗率,仍是目前苗种生产中探索的主要问题.就此笔者认为在锯缘青蟹人工育苗中应注意掌握以下几个方面的技术关键. 相似文献
10.
锯缘青蟹蚤状幼体的饵料试验 总被引：1，自引：0，他引：1
锯缘青蟹（Scylla serrata）人工育苗技术上的低成活率一直制约着青蟹养殖业的发展。吴琴瑟、李少菁、朱小明等都曾对锯缘青蟹的人工育苗技术、幼体营养需求、摄食等方面作了不同程度的研究。学者们一致认为,饵料的选用、搭配和投饵密度的控制是提高青蟹育苗存活率的关键。而幼体前期营养的积累对其后期的变态发育及成活率起着至关重要的作用。有鉴于此,笔者在进行批量生产的同时,选用几种动植物饵料和人工配合饵料对青蟹蚤状幼体进行饵料效果试验,以探讨和比较不同饵料搭配的饲喂方式对幼体发育变态及成活率的影响,以期为锯缘青蟹人工育苗提供一些实践依据。 相似文献
11.
水硬度对七彩神仙鱼幼鱼发育的影响 总被引：4，自引：0，他引：4
采用不同硬度的水对七彩神仙鱼幼鱼进行饲养。6周龄幼鱼在硬度为7.94°dH±0.30°dH时饲养84d后,比在硬度为14.71°dH±0.23°dH水中的幼鱼个体大,生长速度快。表明较高硬度的水有利于七彩神仙鱼幼鱼的生长发育。 相似文献
12.
The variation of virulence of Renibacterium salmoninarum , the causative agent of bacterial kidney disease (BKD) in salmonid fish, was studied by infecting rainbow trout, Oncorhynchus mykiss (Walbaum), with two isolates (strains 325 and 932) from diseased Atlantic salmon, Salmo salar L., and one isolate (strain 4366) from an apparently healthy Atlantic salmon. Coho salmon, Oncorhynchus kisutch (Walbaum), were injected with the strain 932 to estimate difference in fish species resistance. Fish were removed by random sampling for other study purposes, a study design possible with analysis of lifetime distributions incorporating both sampling-, death- and survival-times. At the end of the experiment, the rainbow trout infected with strains 325, 932 and 4366 had a survival probability of 33%, 51% and 72%, respectively. The coho salmon infected with strain 932 had a 26% survival probability. The strain differences were significant according to the log-rank test, and the risk ratio between the strains ranged from 1·8 to 5·4. The strain from the apparently healthy fish was least virulent. The survival of the fish species was different over time. Rainbow trout were more likely to die early in the time course, but high numbers of coho died later, resulting in an overall risk of mortality of 1·4 in favour of rainbow trout. Differences in virulence may reflect changed selective pressure on R. salmoninarum when introduced from feral stocks into the environment of fish farms. 相似文献
13.
《水生生物资源》2003,16(5):461-465
Anti-proteinase activity was demonstrated in the seminal plasma of cyprinid fish species (bream, chub, ide, dace, asp, goldfish, roach, common carp) using electrophoretic techniques combined with a detection method based on inhibition of bovine trypsin. We found species-specific protease inhibitors in the seminal plasma of cyprinids. At least three bands of protease inhibitors with different migration rates could be identified by native PAGE. Higher variability was characterized for bands with slower migration rates. Visualization of inhibitors after SDS-PAGE under non-reducing conditions allowed estimation of their molecular weights. Apparent molecular weights were within the range of 51–59 and 47–54 kDa for the bands with slower and moderate migration rates, respectively. The molecular weight of fast migration bands for roach and common carp were estimated to 23 and 30 kDa, respectively. Inhibitors of common carp seminal plasma differed in their affinity toward serine proteases. Three inhibitors in common carp seminal plasma could be visualized using cod and bovine trypsin, but only two inhibitors (of high molecular weight) were recognized with chymotrypsin. There were differences in anti-proteinase activity and seminal plasma protein concentration in relation to the origin of common carp seminal plasma (breeding lines) and time of milt collection (spawning vs. post-spawning season). 相似文献
14.
15.
该研究通过肉眼观察、镜检,进行干露、饥饿、盐度突降、福尔马林等抗性试验,并采用病毒检测等方法,以期建立评估斑节对虾（Penaeus monodon）虾苗活力和质量标准。结果表明,斑节对虾健康虾苗具有趋光性、集群性,体表光洁,肌肉透亮,肠胃食物充盈等特性。测试虾苗干露时间以15min为宜,健康虾苗干露后能立即恢复活力,而病弱虾苗多出现死亡、昏迷现象;虾苗的成活率随饥饿时间的延长而降低,随福尔马林浓度升高和时间延长而降低,随盐度突降幅度增加而降低。健康虾苗能忍受100～200μL·L^-1福尔马林溶液30min,成活率近100％;在盐度20～30下虾苗的成活情况较好,而其在淡水中仅能存活1h。对虾苗进行病毒检测,可以避免养殖中因虾苗携带病毒而可能导致的病毒性疾病的暴发。 相似文献
16.
鳟鱼发眼卵和旨种运输是养鳟生产的重要环节。发眼卵多在冬季和早春运输,苗种多在晚春和夏季运输。苗种运输大多以鱼篓充氧进行短距离汽车运输,长途运输冷水性鱼苗种的实例很少。本文总结了金鳟和虹鳟苗种长途运输方法,以期与养鳟业界共同交流提高。一、包装材料和方法内包装材料是苗种运输专用塑料袋,规格54×104cm,外包装是泡沫塑料箱,规格63.5×45.5×30．5cm,纸箱规格64×46×32．5cm。塑料袋采取双层式,内装苗种和水共12.5kg,其中苗种0.5-1．3kg,100－2000尾。起运前苗种停食1－2天。运鱼用水水温调至6℃,鱼、水入袋后袋内… 相似文献
17.
该研究选取具有多态性的6对微卫星引物对构建的2批合浦珠母贝(Pinctada fucata)完全双列杂交家系的遗传多样性进行了分析。6个微卫星标记在9个家系360个个体中共检测到32个等位基因,有效等位基因(Ne)为1.758 7~3.586 5,观测杂合度(Ho)为0.144 4~0.488 9,期望杂合度(He)为0.432 0~0.722 2,Shannon指数(I)为0.691 9~1.507 4。9个家系都有单态位点,平均Ho为0.129 2~0.466 7,平均He为0.155 0~0.439 6,平均I为0.248 5~0.712 2。有19个位点(占35.19%)极显著地偏离Hardy-Weinberg平衡。各家系之间的遗传距离为0.109 0~1.137 2,遗传相似性系数为0.320 7~0.896 8。家系L4B46与L4B48的遗传距离最大,与D3D313的遗传距离最小。UPGMA法聚类分析显示,9个家系分为3支,L4B48单独成一支,B4D426、B4D427与D4B445聚成一支,其余家系聚成一支。该研究结果为合浦珠母贝家系选择育种的亲本选择与交配设计提供了科学依据。 相似文献
18.
19.
猪的胎盘属于弥散型胎盘,这种胎盘的结构特点和饲养管理的不当,常常导致母猪胎衣不下发生,给生猪的生产繁殖带来极大损失。本文针对母猪胎衣不下发生病因、综合防治进行详细阐述,旨在对预防和治疗胎衣不下能有所帮助。 相似文献
20.
牙鲆刺激隐核虫病的防治 总被引：1，自引：0，他引：1
2005年七、八月份,乐亭、滦南一带多家工厂化牙鲆养殖场发生刺激隐核虫病,此种病虫害发病急、传染快、死亡率高。发生过该病的养殖场牙鲆死亡率一般都在50％～80％之间,这种病害给牙鲆养殖业带来很大损失。 相似文献