偏分离条件下牙鲆生长性状QTL的主成分定位

本研究利用有丝分裂雌核发育建立牙鲆(Paralichthys olivaceus)双单倍体(Doubled Haploids,DH)群体,对牙鲆体重、全长、背鳍长、腹鳍长、体高、尾柄高、头高和躯干长共8组表型性状标准化处理后,进行主成分分析,得到可解释全部性状90.4%的表型主成分性状。然后,基于JoinMap 4、MapDisto、JoinMap 4-DistortedMap、MapDisto-DistortedMap构建4个连锁图谱,用偏分离标记矫正数量性状位点(Quantitative Trait Locus,QTL)基因型条件概率,采用Bayesian模型选择方法定位牙鲆表型主成分性状的加性QTL和上位性QTL。结果表明,用不同方法构建的遗传图谱和表型主成分性状QTL定位结果均有所不同。在图谱构建中,与基于JoinMap 4构建的图谱相比,基于MapDisto构建的图谱中偏分离标记的相对位置和遗传距离都发生了变化,甚至有5个偏分离标记没有被定位到相应的连锁群上;相对于基于JoinMap 4和MapDisto构建的图谱,经DistortedMap校正后的图谱中偏分离标记的相对位置没有发生变化,但是偏分离标记间遗传距离发生了变化。另外,在4个图谱中都检测到3个加性QTL,分别位于6号连锁群上,可解释表型变异的12.95%、14.85%、11.56%和11.76%,9号、22号连锁群上,具有负向加性效应;9号连锁群上,可解释表型变异的13.86%、13.27%、11.17%和11.25%,具有负向加性效应;22号连锁群上,可解释表型变异的5.68%、4.36%、4.97%和3.58%,具有正向加性效应。同时,分别检测到28对、19对、29对和20对上位性QTL,主要分布在6号、7号、9号、17号、20号和22号连锁群上,可解释表型主成分性状变异的2.19%~17.62%、2.40%~22.26%、2.08%~26.0%、3.16%~22.05%。研究结果表明,基于MapDisto软件构建、经DistortedMap软件包矫正后的图谱,定位结果更加准确,但仍需进一步验证。     

温度对漠斑牙鲆幼鱼生长与存活的影响

本文根据温度实验,对漠斑牙鲆幼鱼的生长及存活的影响进行了探讨。结果表明：漠斑牙鲆幼鱼适宜生长温度范围为15—30℃,最适温度范围为18～27℃。在适宜温度下,漠斑牙鲆幼鱼生长快,存活率高。过高或过低的温度对幼鱼的生长发育均有一定的抑制作用。在生产上,当培育水体温度低于15℃时应进行人为加温,对促进幼鱼的生长发育与存活有积极意义。     

漠斑牙鲆人工催产和自然产卵的比较

为探索漠斑牙鲆人工催产的可行性,以便在预期时间集中获得苗种,分别于2006年在大连和2007年在江苏进行了人工催产和自然产卵对比试验.试验结果表明,漠斑牙鲆亲鱼自然产卵受精率和孵化率远远高于人工催产,但人工催产可以准确掌握生产时机,在短时间内获得大量受精卵和初孵仔鱼;4龄亲鱼人工催产产卵量、受精率、受精卵孵化率高于3龄亲鱼.人工催产受精率孵化率有待于进一步提高.     

不同饵料饲养的褐牙鲆肌肉营养成分的比较

比较分析了分别投喂小杂鱼和人工饲料的两组褐牙鲆肌肉营养成分,旨在为褐牙鲆的营养需求研究及其饲料研制提供参考。结果显示:摄食小杂鱼组的水分含量显著低于摄食人工饲料组(P<0.05),而粗蛋白和粗脂肪含量显著高于摄食人工饲料组(P<0.05),粗灰分含量在两组间差异不显著(P>0.05);两组褐牙鲆的氨基酸组成基本一致,均含有18种氨基酸,必需氨基酸指数(EAAI)分别为71.15和70.47,其构成比例符合FAO/WHO的标准。摄食小杂鱼组褐牙鲆中检测到11种饱和脂肪酸(SFA)、6种单不饱和脂肪酸(MUFA)和9种多不饱和脂肪酸(PUFA);摄食人工饲料组中检测到11种SFA、7种MUFA和9种PUFA。摄食小杂鱼组的∑ω3PUFA[(30.39±2.29)%]显著低于摄食人工饲料组[(34.40±3.32)%](P<0.05),其中小杂鱼组的EPA+DHA的总量为(29.27±2.33)%,显著低于摄食人工饲料组的(33.47±3.36)%(P<0.05);摄食小杂鱼组的∑ω6PUFA为(6.01±0.31)%,显著高于摄食人工饲料组的(5.06±0.37)%(P<0.05)。综合来看,两组褐牙鲆均含有丰富的各种营养成分,摄食小杂鱼组的粗蛋白、粗脂肪和氨基酸营养较好,而摄食人工饲料组的多不饱和脂肪酸营养较好,两者各有优势。     

Cytological studies on induced meiogynogenesis in Japanese flounder Paralichthys olivaceus (Temminck et Schlegel)

The cytological process of induced gynogenetic development and subsequent chromosome duplication by a cold shock treatment was observed in Japanese flounder Paralichthys olivaceus (Temminck et Schlegel). Mature eggs were at the metaphase of the second meiosis when inseminated with ultraviolet (UV)-irradiated sperm of red sea bream Pagrus major . After the beginning of cold shock treatment, the previously visible spindle became invisible, probably due to the side effect caused by cold shock treatment. The chromosomes at the centre of the metaphase plate were condensed. This condition continued during the duration of the cold shock treatment and several minutes after it. The release of the second polar body was blocked and it developed into a female-like pronucleus. Then, it fused with the female pronucleus to generate a diploid zygotic nucleus, and the egg exhibited the first mitosis. Consequently, the haploid female chromosome set of the egg was doubled by the inhibition of the second polar body release. There was a significant delay in developmental time in the gynogenetic eggs when compared with that in the normal eggs. From the time of insemination to early cleavage, the UV-irradiated heterospecific sperm nucleus remained condensed.     

pH对褐牙鲆幼鱼血红蛋白含量和血中溶氧水平的影响

17&#177;0．5℃及实验室条件下,研究了水体pH突变[pH8．0突变到6．0、8．0（对照）和9．0]对褐牙鲆Paralichthys olivaceus幼鱼血红蛋白含量和血中溶氧水平的影响。实验时间为12h。结果发现,实验期间褐牙鲆幼鱼的血红蛋白含量呈现波动变化,但方差分析显示,水体pH突变对实验鱼血红蛋白含量无显著影响（P〉0．05）。实验4h,水体pH由8．0突变到6．0和9．0均导致实验鱼血中溶氧水平的极显著下降（P〈0．01）。然而实验4—12h期间,水体pH突变处理组实验鱼的血中溶氧水平随实验时间的增加而上升。实验结果表明,与血红蛋白含量相比,褐牙鲆幼鱼血中溶氧水平对水体pH的变化反应更敏感。     

Induction of diploid gynogenesis in turbot <Emphasis Type="Italic">Scophthalmus maximus</Emphasis> with left-eyed flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis> sperm

Turbot Scophthalmus maximus exhibits sexually dimorphic growth, with females growing faster and reaching larger adult sizes than males. Thus, development of techniques for preferentially producing females is necessary to optimize production of these species. In this paper, gynogenetic diploids of turbot were induced by activating egg development with ultraviolet (UV)-irradiated left-eyed flounder Paralichthys olivaceus sperm combined with cold shock to prevent extrusion of the second polar body. The results of UV irradiation experiments showed that survival, motility, and duration of activity of P. olivaceus sperm generally decreased with increase in UV dose. The typical Hertwig’s effect was observed after fertilized turbot eggs with UV-irradiated P. olivaceus sperm and the optimal UV dose for gynogenetic haploid production was 36,000 erg mm⁻². At 15°C, appropriate timing of cold shock for retention of the second polar body in turbot eggs was at 6 min after fertilization. Results of different combinations of two shock temperatures (1 or 3°C) and four shock durations (15, 25, 35 or 45 min) at 6 min after fertilization demonstrated that shock of 25 min at 1°C gave the highest production of diploid gynogens (39.58% relative to its diploid control). The results of this study reveal that the use of UV-irradiated P. olivaceus sperm for activation of turbot eggs and cold shock for polar body retention is an effective method to produce gynogenetic offspring.     

养殖褐牙鲆的极限品质及锁鲜调控

为构建工厂化养殖鱼类鲜活品质的渔后调控技术体系，以极限品质为着眼点，解读海水养殖白肉鱼刺身级品质形成及变化机制，以褐牙鲆为研究对象，从致死方式着手，探究肌肉品质的极限，即通过极端处置以探索其鲜活品质的极限。以破髓处置（SCD）得到上限品质，窒息致死(SA)得到下限品质，对照商业操作即断髓处置(SCC),3个致死处理组均于2°C下冷藏120 h。期间分别对僵直、断裂强度、肌肉收缩率、肌肉pH值、ATP及关联物、白度、显微结构和体表颜色进行分析。致死应激对品质及稳定性的影响至关重要，最强致死应激SA组死后6～12 h快速进入僵直，随即解僵。而最低致死应激SCD组死后48～72 h方达到最大僵直，且僵直指数缓慢上升，呈现出最好的冷藏稳定性。常规商业处置SCC组则介于二者之间，但明显优于下限SA组，逊于上限SCD组。同样的，最低致死应激SCD组保留最高的ATP，死后12 h各处理组肌肉ATP含量由初始的3.13μmol/g分别下降至SCD组2.13μmol/g、SCC组1.99μmol/g及SA组0μmol/g。肌肉降至极限pH的时间分别为SCD组在48 h,SCC组在48 h,SA组则在死后...