漠斑牙鲆(Paralichthys lethostigma)养殖群体微卫星座位遗传多态性的分析

为了解漠斑牙鲆群体的遗传背景,并为漠斑牙鲆人工养殖业健康和可持续发展提供理论依据,利用筛选获得的10对微卫星引物对漠斑牙鲆(Paralichthys lethostigma)养殖群体进行了群体遗传学分析。该群体等位基因平均数为4.0,平均杂合度为0.597 7。各多态座位的有效等位基因数则为1.7~4.1,多态座位杂合度的观察值为0.291 7~0.958 3,无偏倚期望值范围为0.405 3~0.755 3,Hardy-Weinberg遗传偏离指数为-0.451 7~0.346 6。每个座位上的多态信息含量为0.353~0.746,个体识别率为0.176~0.559,非父排除率为0.405~0.755,其累积个体识别率和非父排除率均达到0.999 9和0.993 7,这些座位均属中识别力以上的遗传标记,可以应用于今后的漠斑牙鲆的遗传育种(如雌核发育等)研究。     

迟缓爱德华氏菌对牙鲆免疫器官的影响

当经口腔灌注大量迟缓爱德华氏菌后,牙Ｐｉｎｇ的头肾和脾脏内的免疫细胞活性增强,表现为单核细胞数量增加,颗粒细胞内产生大量的颗粒以及颗粒吞噬作用的增强。研究结果还表明,病菌也会对免疫器官产生损害,可造成细胞水肿,膜性结构破坏及细胞坏死。本文详细观察了牙Ｐｉｎｇ肾、脾、肝、肠及血液的显微结构和肾、脾、肝的超微结构的变化,研究结果对疫苗的应用提供了良好的细胞学基础。     

重组酵母菌对牙鲆非特异性免疫能力的影响

于１９９９年１０－１１月间在荣成市寻山养殖场实验了饲喂含有大麻哈鱼生长激素基因的重组酵母对１龄牙鲆非特异性免疫能力的影响。实验分为对照组和３个实验组,对照组的饵料中不含重酵母菌,实验组我饵料中分别含有重组酵母菌０．２５‰、０．５０‰、０．７５‰（Ｗ／Ｗ）。实验表明,通过投喂重组酵母菌,可以增加牙鲆血清蛋白的含量,增强牙鲆血清中深菌酶及抗蛋白酶物质的活性,这种影响与重组酵母菌的含量成正相关。     

漠斑牙鲆养殖群体RAPD遗传多样性的初步分析

利用RAPD技术对由美国引进的漠斑牙鲆(Paralichthys lethostigma)养殖子一代群体的遗传多样性进行了研究。实验用漠斑牙鲆鱼苗于2004年10月取自山东莱州大华水产有限公司,共24尾,全长平均为16.6 mm±1.99 mm。活体取其肌肉,用高盐法抽提获得总DNA,琼脂糖电泳检测,Beckman DU-6100型紫外分光光度仪定量后用随机引物进行PCR扩增,从25个随机引物中筛选出11个用于群体遗传学分析,共获得77条清晰重复性高的DNA片段,大小在100~2 000 bp之间,多态谱带比例和群体平均杂合度分别为66.23%和0.352 6。     

饲料中添加锌对牙鲆生长和生化指标的影响

含锌３７．５ｍｇ／ｋｇ的基础饲料中,分别加入锌０,１５,３０,５０,８０ｍｇ／ｋｇ,饲喂初重为３０．８５～３４．８５ｇ的牙鲆幼鱼１个月。结果表明,饲料中添加锌,鱼的增重率、肝脏锌含量、肠粘膜碱性磷酸酶活性都高于不添加组;且有随添加量加大而增加的趋势。当添加锌８０ｍｇ／ｋｇ时,此３项指标达到最大,分别为１１２．７％,４３．８ｍｇ／ｋｇ和１８．２８Ｕ／ｍｇ蛋白质。但添加锌没有影响鱼的成活率和肌肉锌含量。此结果说明,添加锌对牙鲆鱼苗具有促生长作用。建议在牙鲆的实用饲料中,锌添加量应大于８０ｍｇ／ｋｇ,锌的总含量应在１１９．２ｍｇ／ｋｇ以上。     

牙鲆dmrt1 基因的克隆及其与P450arom 基因的组织表达分析

通过基因组步移和3’RACE获得了牙鲆(Paralichthys olivaceus)dmrt1的cDNA全序列,该基因开放阅读框全长909bp,其编码的蛋白具有高度保守的DM结构域,5’UTR区含有性别相关转录因子Sox9和Sox5的结合位点。牙鲆dmrt1基因只在牙鲆的性腺中表达,且在精巢中的表达明显高于卵巢,表明牙鲆的dmrt1可能是一种性别相关基因。同时,对牙鲆的另一性别相关基因P450arom在成体各组织的表达分析结果表明,该基因除在牙鲆的性腺中有表达外,在肾脏、脾脏、鳃和脑等其他组织中也有不同程度的表达。牙鲆P450arom基因在性腺中的表达也存在两性差异,其表达模式与dmrt1的正好相反,在卵巢中的表达量明显高于精巢。     

Screening of eye-position related genes with DD-RT-PCR and RDA in the hybrids between Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis> and stone flounder <Emphasis Type="Italic">Kareius bicoloratus</Emphasis>

Flatfish or flounder moves one eye to change body proportion into vertebral asymmetry during metamorphosis, during which some become sinistral while others dextral. However, the mechanism behinds the eye-position has not been well understood. In this research, hybrids between Japanese flounder(♀) and stone flounder (♂) show mixed eye-location in both dextral type and sinistral type, and thus become good samples for studying the eye-migration. mRNAs from pro-metamorphosis sinistral and dextral hybrids larvae were screened with classical differential display RT-PCR (DD-RT-PCR) and representational difference analysis of cDNA (cDNA-RDA); 30 and 47 putative fragments were isolated, respectively. The cDNA fragments of creatine kinase and trypsinogen 2 precursor genes isolated by cDNA-RDA exhibited eye-position expression patterns during metamorphosis. However, none of the fragments was proved to be related to flatfishes’ eye-position specifically. Therefore, further studies and more sensitive gene isolated methods are needed to solve the problems. Supported by National Natural Science Foundation of China (No. 30600455) and the National Basic Research Program of China (973 Program, No.2004CB117402)     

Cytogenetic characterization of olive flounder Paralichthys olivaceus: DNA content, karyotype, AgNORs and location of major ribosomal genes

A cytogenetic analysis of Paralichthys olivaceus was carried out using the flow cytometry method for DNA content, silver staining for the nucleolus organizer region (AgNORs) identification and one-color fluorescence in situ hybridization (FISH) for chromosomal mapping of major ribosomal genes. Nuclear DNA content was estimated by flow cytometry method using Gallus domesticus erythrocytes as the internal reference standard. The C-value of this species was (0.737±0.024) pg, and the DNA contents of each chromo...     

牙鲆出血性败血病病原的初步研究

经病原菌的分离、纯化、人工感染和生理生化测定 ,认为变异微球菌为牙鲆出血性败血病的病原菌。菌体为圆形或椭圆形 ,单个、成对排列或成短链、四联及不规则的堆团。单个菌大小为 0 .5～ 1.8μm。无鞭毛 ,不运动 ,无牙孢 ,无荚膜。革兰氏阳性 ,不抗酸。好氧菌、葡萄糖 O- F试验为氧化型。测定的2 2种糖苷醇类中 ,仅葡萄糖、D-果糖、蔗糖、麦芽糖、甘油为好氧产酸 ,D-甘露糖弱产酸 ,且均不产气。氧化酶、过氧化氢酶阳性 ,硝酸盐还原、美兰还原为阳性。甲基红、V- P反应为阳性。能水解明胶、马尿酸钠 ,不能水解七叶苷、淀粉。不产生硫化氢、吲哚。不能利用柠檬酸盐、丙二酸盐。精氨酸双水解酶、赖氨酸脱羧酶、鸟氨酸脱羧酶、脲酶阴性 ,卵磷脂酶、凝固酶阳性。不溶血。先锋霉素、氯霉素、青霉素、红霉素为该病原菌的敏感药物     

Distribution, condition, and growth of newly settled southern flounder (Paralichthys lethostigma) in the Galveston Bay Estuary, TX

Several flatfish species, including southern flounder (Paralichthys lethostigma) recruit to estuaries during early life. Therefore, evaluation of estuarine sites and habitats that serve as nurseries is critical to conservation and management. The present study used density data in conjunction with biochemical condition and growth measurements to evaluate settlement sites used by southern flounder in the Galveston Bay Estuary (GBE). In 2005, beam-trawl collections were made in three major sections of the GBE (East Bay, Galveston Bay, West Bay). Three sites were sampled in each bay. Within each sampling site, replicate collections were taken from three habitats: 1) marsh edge (< 1 m depth), 2) intermediate zone (10–20 m from marsh interface;  1 m depth), and 3) bay zone (typically > 100 m from marsh interface; depth > 1 m). Average size of southern flounder collected was 12–19 mm standard length, and peak densities occurred in January and February. Catch data indicated that densities of southern flounder were significantly greater in East Bay (2.75 per 100 m²) than in Galveston Bay (0.91 per 100 m²) or in West Bay (0.45 per 100 m²). Densities were statistically similar among habitats. Otolith-based estimates of age indicated that the majority of southern flounder collected were 35–45 days old and derived from early December to early January hatch-dates. Growth rates were similar among bays and among habitats, with the average growth rate being 0.40 mm day^− 1 (range: 0.21–0.76 mm day^− 1). RNA:DNA was above the established baseline value for nutritional stress, indicating that newly settled southern flounder in the GBE were in relatively high condition. Habitat-specific differences in RNA:DNA ratios were not observed; however, ratios were significantly lower in West Bay (average 8.0) than in East Bay (average 9.5) or in Galveston Bay (average 9.8), suggesting the condition of new recruits may vary spatially within the GBE. Findings from the current study suggest density and condition of newly settled southern flounder vary at the bay scale, suggesting that parts of GBE do not function equally as nurseries.