黄带拟鲹染色体核型特征分析

鱼类染色体核型分析在种质资源保护、遗传图谱构建、鱼类分类和育种等方面发挥着重要作用.黄带拟鲹(Pseudocaranx dentex,Bloch&Schneider,1801)是具有较高经济价值和遗传育种价值的水产资源物种,目前与该物种遗传背景相关的研究尚属空白.本研究采用热滴片法制备了黄带拟鲹鳃和鳍条组织的染色体标本...     

黄带拟鲹养殖技术

在室内工厂化循环水养殖车间和海上网箱开展黄带拟鲹(Pseudocaranx dentex)养殖试验研究.通过试验观察掌握了黄带拟鲹的生物学特点,摸清了其温度、溶解氧等主要水质指标的要求及适宜的饵料种类和投喂模式,在此基础上突破了室内工厂化及海上网箱黄带拟鲹养殖技术.工厂化养殖产量15～20 kg/m3,网海养殖产量10...     

黄带拟鲹肌肉营养成分分析

黄带拟鲹(Pseudocaranx dentex)肌肉鲜嫩味美,是刺身、寿司等上等食材的来源.为全面认识黄带拟鲹的营养价值,该研究采用生化法对其肌肉营养成分进行检测,并评价其营养品质.结果显示,黄带拟鲹肌肉粗蛋白含量较高.在氨基酸水平,必需氨基酸占总氨基酸的40.67％,鲜味氨基酸占总氨基酸的35.37％,符合FAO/...     

黄带拟鲹线粒体基因组测序及鲹科鱼类系统发育分析

摘要: 为深入开展黄带拟鲹种质鉴定、分类及遗传进化等研究,通过二代高通量测序与生物信息学分析,揭示了黄带拟鲹(Pseudocaranx dentex)线粒体基因组全序列基因结构及鲹科鱼类系统发育特征。结果显示,黄带拟鰺线粒体基因组为典型的环状DNA结构,序列全长为16 570 bp,碱基组成分别为A(27.2 %)、G(17.18%)、C(30.24%)和T(25.38%),包括13种蛋白编码基因,22个tRNA基因,2个rRNA基因,除ND6、tRNAGln、tRNAAla、tRNAAsn、tRNACys、tRNATyr、tRNASer、tRNAGlu、tRNAPro外,其余基因均在H链上编码,且基因组存在多处重叠区域。除CO Ⅰ和ND5的起始密码子分别为ATC和ATA外,其余11个蛋白编码基因的起始密码子均为ATG,以典型的TAA和TAG为终止密码子,在Cyt b中存在不完全终止密码子T;黄带拟鲹线粒体基因组全序列与蛋白编码基因的A+T含量分别为52.58%和51.55%,非编码控制区(D-loop)A+T富含61.69%,具有明显的AT偏好性。除tRNASer-(GCT)外,其余21个tRNA均含典型三叶草二级结构。为进一步研究黄带拟鲹系统进化特性,通过与18种鲹科鱼类线粒体基因组全序列及16S rRNA基因构建系统进化树显示,黄带拟鲹与高体若鲹同属一个分支,亲缘关系最近。结果可为黄带拟鲹物种鉴别、遗传多样性评价与保护提供技术依据。     

高光胁迫下坛紫菜定量PCR内参基因的筛选

为了筛选不同高光光强胁迫下坛紫菜中表达水平最为稳定的内参基因,本研究采用qRT-PCR技术测定了植物中常用的6种内参基因UBC、TUB、18S、EF2、ACT和GAPDH在不同光照强度下培养的坛紫菜藻体中的绝对表达水平,并采用比较Ct值法、Ge Norm、Bestkeeper和NormFinder软件分析4种方法对6种候选内参基因的表达稳定性进行评估。结果显示,UBC的Ct值变化范围最小,18S的Ct值变化范围最大;ge Norm软件分析结果显示最稳定的内参基因为UBC和EF2;Bestkeeper和NormFinder软件分析结果类似,UBC基因的稳定值M均为最低值(分别为0.044和0.80),说明其表达水平最稳定。研究表明,UBC基因可以作为不同光照条件下坛紫菜基因表达qRT-PCR分析的最适内参基因。     

温度对黄带拟鲹耗氧率、排氨率及窒息点的影响

利用实验生态学方法研究了不同温度(17、21、25℃)对黄带拟鲹Pseudocaranx dentex(389.34 g±49.70 g)耗氧率、排氨率及窒息点的影响.结果显示:17℃组耗氧率为(0.26±0.01)m g/(g·h),排氨率为(3.12±0.25)μg/(g·h),窒息点为(0.85±0.13)mg/...     

异育银鲫内参基因的筛选

内参基因在实时荧光定量PCR(qRT-PCR)中具有校准的作用,然而鲤疱疹病毒Ⅱ型感染异育银鲫内参基因目前仍未见研究报道。采用qRT-PCR技术检测不同处理条件下异育银鲫组织和尾鳍细胞GAPDH、EF-1α、18S rRNA和β-actin 4个候选内参基因在组织和尾鳍细胞的转录水平,利用软件geNorm、Norm Finder、Best Keeper和Delta Ct分析了其表达量的稳定性,以筛选出健康异育银鲫不同组织以及鲤疱疹病毒Ⅱ型感染的肾脏、脾脏和异育银鲫尾鳍细胞在不同时间均较稳定的内参基因。geNorm稳定值以及4个内参的表达量Ct值分析显示,健康异育银鲫脑、脾脏、肾脏、肌肉、鳃、肠、肝脏和心脏组织中β-actin和EF-1α都是比较稳定的内参基因;鲤疱疹病毒Ⅱ型感染肾脏和尾鳍细胞不同时间点,内参基因β-actin稳定性最佳;鲤疱疹病毒Ⅱ型感染脾脏不同时间点时,EF-1α稳定性最佳。分别以4个候选内参基因为内参分析PIN1基因在肾脏组织不同感染时间的相对表达量,结果进一步证实,PIN1基因在肾脏组织感染不同时间点以β-actin为内参时,其表达量呈下降趋势,与cDNA文库测序...     

达氏鲟实时荧光定量PCR内参基因的筛选

实时荧光定量PCR（qRT-PCR）是基因表达研究的常用方法,筛选达氏鲟（肌动蛋白（）、18S核糖体RNA（）共7个常用内参基因作为候选基因,利用geNorm、NormFinder、BestKeeper和RefFinder 4个软件分析这7个候选基因在达氏鲟成鱼不同组织和不同发育时期胚胎及性腺的表达稳定性。结果表明,7个候选内参基因的定量PCR引物均可获得特异性扩增产物和理想的扩增效率。在成鱼不同组织中,候选内参基因稳定性由高到低的顺序为18S rRNA > > GAPDH > -actin > ;在不同发育时期卵巢中,候选内参基因稳定性由高到低的顺序为 > ,而不同发育卵巢最稳定表达的内参基因是。本研究旨在为今后达氏鲟不同组织、不同发育时期胚胎及性腺的基因表达差异研究提供理论基础。     

地榆醇提物对对虾致病菌VPAHPND生长影响及最适内参基因的筛选

为筛选适用于研究地榆(Sanguisorba officinalis L.)对对虾急性肝胰腺坏死病致病株副溶血弧菌(Acute hepatopancreatic necrosis disease caused by Vibrio parahaemolyticus, VPAHPND)抑制机理的内参基因,本文探究了地榆醇提物胁迫下VPAHPND生长的变化,并利用qRT-PCR技术探究了该条件下VPAHPND中 6种常见内参基因(rec A、pvs A、pvu A、gapdh、16S rRNA和rpo S)的表达情况,利用GeNorm、Norm Finder、Best Keeper、Delta CT以及Ref Finder这5种方法对其表达稳定性进行了评估和筛选。结果显示,地榆醇提物能抑制VPAHPND的生长,且抑制效果与浓度呈正相关。在不同浓度地榆醇提物处理条件下,这 6种内参基因扩增产物特异性良好,其中,Ct值变化差异最小的为16S rRNA (CV=3.88),变化差异最显著的为pvs A (CV=12.53)。5种方法对6种内参基因稳定性排序略有差异,其中,GeNorm给出的稳定性排序为rpo S = 16S rRNA > gapdh > rec A> pvu A > pvs A;Norm Finder结果为gapdh > rpo S > pvu A > 16S rRNA > rec A > pvs A;Best Keeper结果为16S rRNA > rpo S > gapdh > rec A > pvu A > pvs A;Delta Ct结果为gapdh > rpo S > pvu A > 16S rRNA > rec A > pvs A;Ref Finder综合排名结果为rpo S > gapdh > 16S rRNA > pvu A > pvs A > rec A。本研究根据配对变异系数结果,最终推荐同时使用rpo S和gapdh作为该条件下内参基因。本研究为以地榆为核心药物的AHPND防控技术的建立和从基因表达角度研究地榆对VPAHPND的作用机理提供了基础。     

青海湖裸鲤实时荧光定量PCR内参基因筛选与验证

为探明青海湖裸鲤候选内参基因在低温环境下的表达稳定性,根据RNA-seq定量结果筛选表达稳定的候选内参基因,利用实时荧光定量PCR检测候选基因在0℃和17℃下,脑、肝胰脏、肌肉组织中的表达量,并通过GeNorm、Norm Finder和Best Keeper 3种分析程序分析其表达稳定性,筛选出理想的内参基因。结果显示：根据RNA-seq定量结果,共筛选获得脱水酶(Abhd18)基因、微球蛋白(B2m)基因、延伸蛋白A(Eloa)基因、DAZ相关蛋白2(Dazap2)基因、肌动蛋白(Actb)基因、磷酸甘油醛脱氢酶(Gapdh)基因、BCL细胞死亡激动因子(Bad)基因和脂肪酸结合蛋白3(Fabp3)基因等8个候选基因;对上述基因的表达稳定性进行分析,发现表达最稳定的是B2m和Eloa基因,表达最不稳定的是Fabp3基因;利用B2m和Eloa基因作为双内参基因对4个脂肪酸代谢相关基因在0℃和17℃脑、肝胰脏、肌肉组织中的表达量进行校正,其相对表达比值与RNA-seq结果高度正相关。研究结果可为高原鱼类极端环境适应的研究提供候选内参基因。     

Exophiala xenobiotica infection in cultured striped jack, Pseudocaranx dentex (Bloch & Schneider), in Japan

This report describes Exophiala infection in cultured striped jack, Pseudocaranx dentex , in Japan in 2005. One hundred out of 35 000 fish died per day and mortalities continued for 1 month. Diseased fish showed swelling of the abdomen and kidney distension. Numerous septate hyphae, pale brown in colour, were seen in kidney in squash preparations. Histology revealed abundant fungal hyphae and conidia in gill, heart and kidney. Fungal hyphae were accompanied by cell necrosis and influx of inflammatory, mainly mononuclear cells. The fungus isolated from the diseased fish had septate hyphae, pale brown in colour and 1.8–3.0 μm in diameter. Conidiogenous cells were conspicuous annellides, short or cylindrical or fusiform in shape. Conidia were one-celled, ellipsoidal with smooth walls, accumulated in balls at the apices of annellides that tended to slide down, 1.5–2.0 μm in width and 3.0–5.0 μm in length. The fungus was classified into the genus Exophiala based on its morphology and as Exophiala xenobiotica based on the sequences of the ITS 1–5.8S–ITS 2 regions of rDNA. This is the first record of this fungus in a marine fish.     

Effects of dry pellets containing astaxanthin and squid meal on the spawning performance of striped jack Pseudocaranx dentex

ABSTRACT: This study was conducted to investigate the effect of squid meal and astaxanthin in dry pellets on the spawning performance of striped jack. Two groups of 8-year-old fish with an average bodyweight of 3.5 ± 0.4 kg were used. The control group was fed a raw fish mix (RF) and the experimental group was fed steam dry pellets (as-DP) containing 10 p.p.m. astaxanthin and squid meal, the latter replacing half the fish meal. Each group was fed once a day, three times a week in floating net cages for a period of 5 months. Seven females and seven males were selected from each group and transferred to 65 m³ indoor concrete tanks for spawning, where they were kept at optimum spawning conditions (22°C) for 1 month. The average bodyweights of selected fish were 3.8 ± 0.5 kg and 3.8 ± 0.6 kg for the RF and as-DP groups, respectively. Both groups spawned a total of 18 times and the mean total egg production and egg quality, measured in terms of buoyancy, fertilization and hatching rates, showed no significant differences ( P > 0.05) between groups. Total larval production was 679.9 × 10³ and 678.1 × 10³ larvae/kg-female for the RF and as-DP groups, respectively. These results show that the combination of astaxanthin and squid meal in dry pellets for striped jack broodstock improved the overall spawning performance to a level similar to that of fish fed on RF.     

Effect of squid meal in dry pellets on the spawning performance of striped jack Pseudocaranx dentex

SUMMARY: This study was carried out to investigate the effects of dietary squid meal or a combination of squid meal and krill meal as part of the protein source in dry pellets on the spawning of striped jack Pseudocaranx dentex . Five months prior to spawning, 7-year-old fish were divided into three groups of 10 fish each (male : female ratio, 5 : 5). The control group was fed a raw fish mix (RF) and the other two groups were fed either steam-dry pellets with squid meal replacing 50% of their fish meal (fs-DP) or steam-dry pellets containing equal proportions of fish, squid and krill meals (fsk-DP). Feeding was carried out once every other day in 5 × 5 × 5 m floating net cages and the fish were transferred to 65 m³ indoor tanks for spawning. Eggs and yolksac larvae produced were evaluated for their quality and those obtained during the first 2 weeks of spawning were sampled for chemical analysis. The fish had an average bodyweight of 3.5 ± 0.4 kg at spawning. Although egg production of the RF group was significantly higher ( P < 0.05) than that of the dry pellet groups, the fs-DP group produced the best quality eggs with higher fertilization and hatching rates. The fsk-DP group had the lowest egg production and quality. Lipid classes and fatty acid compositions of eggs and yolksac larvae were dependent on the broodstock diets. These results show that the combination of fish meal and squid meal in dry pellets for striped jack improved egg quality but not production whereas the combination of fish meal, squid meal and krill meal was not effective.     

神经坏死症病毒对长缟鲹仔鱼的感染及在体内的传播

以长缟鲹(Pseudocaranx dentex)孵化仔鱼为材料，通过神经坏死病毒(Nervous Necrosis Virus，NNV)浸浴感染实验，明确病毒浓度越高，供试鱼被病毒感染的时间越早，病毒检出率越高；运用细胞组织病理学和酶联免疫(Enzyme-1inked immunosorbent assays，ELISA)的原理和方法，了解了神经坏死病毒的侵入、感染和在神经组织中的扩散方式；利用ELISA技术，结合电子显微镜对NNV感染细胞进行超显微观察，确认育苗水环境中神经坏死病毒可水平感染供试鱼皮肤上皮的基底细胞；病毒感染细胞发生细胞质内质网膨胀、细胞核变性、细胞小器官数减少等病理变化；病毒感染细胞质中病毒粒子有散布、类结晶和二者兼有3种存在形式。本研究成果可为了解海水鱼类人工育苗的病毒性神经坏死症感染途径、传播和预防病毒性神经坏死症的发生提供科学依据。     

Pathogenicity of the causative agent of viral nervous necrosis disease in striped jack, Pseudocaranx dentex (Bloch & Schneider)

Abstract. The pathogenicity of the agent causing viral nervous necrosis (VNN) of striped jack, Pseudocaranx dentex (Bloch & Schneider), was examined in striped jack and other selected marine fish species. Fish were exposed to purified striped jack nervous necrosis virus (SJNNV) (0·1–100 ng ml⁻¹) or homogenates of diseased striped jack larvae. Striped jack larvae (3·5 and 4·4 mm total length) were susceptible to the virus, but juveniles (78 mm) were not. The viral antigens were detected by indirect ELISA and the characteristic pathological changes, i.e. vacuolation in the retina and brain, were reproduced in the affected larvae. The infection was also established in healthy larvae by cohabitation with the diseased larvae. Larvae of red sea bream, Pagrus major Temminck & Schlegel, yellowtail, Seriola quinqueradiata Temminck & Schlegel, and goldstriped amberjack, Seriola lalandi Valenciennes, were not susceptible to SJNNV.     

Development of the common dentex (Dentex dentex) eggs in relation to temperature

Embryonic development of common dentex (Dentex dentex) was investigated at nine different constant water temperatures (8°C, 10°C, 12°C, 14°C, 16°C, 18°C, 20°C, 22°C and 24°C). The observed effects were compared using of regression analysis. Constant water temperatures between 12°C and 18°C were found to support successful embryonic development. A negative relationship between the rate of embryonic development and incubation temperature was observed. While embryonic development was completed within this range (12°C–18°C), there was no cell division at water temperatures of 8°C and 24°C. Total mortalities were observed at the 128 cleavage stage at a temperature of 10°C, and after the beginning of gastrulation at 20°C and 22°C.     

Assessing the spawning season in common dentex (Dentex dentex) using microsatellites

A set of five variable microsatellite markers was used for the genetic characterization of two common dentex ( Dentex dentex ) broodstocks from an experimental hatchery and for the screening of the egg batches spawned during the complete spawn season in 2006. After parentage assignment, simulations were performed for the hatchery 1 broodstocks; the microsatellite set correctly assigned over 93% of descendants to parents when one parent was known and 80% when neither parent was known. Of the 261 eggs that the DNA was correctly amplified from, 254 were successfully assigned to a parental couple. More than one female or male took part (at the same point in time) in the spawning season. However, we observed 'dominant' individuals that produced high proportions of the descendants (unequal reproductive success) in all the sampling periods, although the contributions of these dominant individuals could change over time. This phenomenon reduces the effective breeding numbers, and could lead to inbreeding if this factor is not taken into account when the next parental generation is obtained. This factor should also be considered in aquaculture selection programmes because the dominant breeders may not be the most interesting individuals for commercial or productive schemes.     

Stress-related physiological responses to handling in common dentex (Dentex dentex Linnaeus, 1758)

The effects of handling on haematocrit, haemoglobin, plasma glucose, lactate and total amino acids, liver glycogen and hepatic activity of fructose 1,6‐bisphosphatase (FBPase) and alanine aminotransferase (AAT) were investigated in common dentex (Dentex dentex Linnaeus, 1758). A total of 42 fish (50‐g weight) were subjected to handling (netting and shaking in the air for 45 s). Six fish were sampled at 0, 0.5, 1, 2, 4, 8 and 12 h after handling. Six unstressed fish were also sacrificed at each time and used as controls. Handling resulted in a rise in plasma glucose and lactate levels, as well as in enhanced hepatic FBPase and AAT activities. In most cases values returned to control levels 8 h after handling. There were no significant changes in haematocrit, haemoglobin, plasma total amino acids and liver glycogen levels as a consequence of handling. The results suggest that dentex is rather tolerant to handling; apparently, sensitivity to handling is not the main factor responsible for the low survival exhibited by this species in aquaculture.