Diploid Trout Research Articles

Comparison of triploid and diploid rainbow trout (Oncorhynchus mykiss) fine-scale movement, migration and catchability in lowland lakes of western Washington

Fisheries managers stock triploid (i.e., infertile, artificially produced) rainbow trout Oncorhynchus mykiss in North American lakes to support sport fisheries while minimizing the risk of genetic introgression between hatchery and wild trout. In Washington State, the Washington Department of Fish and Wildlife (WDFW) allocates approximately US $3 million annually to stock hatchery-origin rainbow trout in > 600 lakes, yet only about 10% of them are triploids. Many lakes in Washington State drain into waters that support wild anadromous steelhead O. mykiss that are listed as threatened under the U.S. Endangered Species Act. As a result, there is a strong interest in understanding the costs and benefits associated with stocking sterile, triploid rainbow trout as an alternative to traditional diploids. The objectives of this study were to compare triploid and diploid rainbow trout in terms of: (1) contribution to the sport fishery catch, (2) fine-scale movements within the study lakes, (3) rate of emigration from the lake, and (4) natural mortality. Our results demonstrated that triploid and diploid trout had similar day-night distribution patterns, but triploid trout exhibited a lower emigration rate from the lake and lower catch rates in some lakes. Overall, triploid rainbow trout represent a viable alternative to stocking of diploids, especially in lakes draining to rivers, because they are sterile, have comparable home ranges, and less often migrate.

Crosstalk between Growth and Osmoregulation of GHRH-SST-GH-IGF Axis in Triploid Rainbow Trout (Oncorhynchus mykiss).

Smolting is an important development stage of salmonid, and an energy trade-off occurs between osmotic regulation and growth during smolting in rainbow trout (Oncorhynchus mykiss). Growth hormone releasing hormone, somatostatin, growth hormone and insulin-like growth factor (GHRH-SST-GH-IGF) axis exhibit pleiotropic effects in regulating growth and osmotic adaptation. Due to salmonid specific genome duplication, increased paralogs are identified in the ghrh-sst-gh-igf axis, however, their physiology in modulating osmoregulation has yet to be investigated. In this study, seven sst genes (sst1a, sst1b, sst2, sst3a, sst3b, sst5, sst6) were identified in trout. We further investigated the ghrh-sst-gh-igf axis of diploid and triploid trout in response to seawater challenge. Kidney sst (sst1b, sst2, sst5) and sstr (sstr1b1, sstr5a, sstr5b) expressions were changed (more than 2-fold increase (except for sstr5a with 1.99-fold increase) or less than 0.5-fold decrease) due to osmoregulation, suggesting a pleiotropic physiology of SSTs in modulating growth and smoltification. Triploid trout showed significantly down-regulated brain sstr1b1 and igfbp2a1 (p < 0.05), while diploid trout showed up-regulated brain igfbp1a1 (~2.61-fold, p = 0.057) and igfbp2a subtypes (~1.38-fold, p < 0.05), suggesting triploid trout exhibited a better acclimation to the seawater environment. The triploid trout showed up-regulated kidney igfbp5a subtypes (~6.62 and 7.25-fold, p = 0.099 and 0.078) and significantly down-regulated igfbp5b2 (~0.37-fold, p < 0.05), showing a conserved physiology of teleost IGFBP5a in regulating osmoregulation. The IGFBP6 subtypes are involved in energy and nutritional regulation. Distinctive igfbp6 subtypes patterns (p < 0.05) potentially indicated trout triggered energy redistribution in brain and kidney during osmoregulatory regulation. In conclusion, we showed that the GHRH-SST-GH-IGF axis exhibited pleiotropic effects in regulating growth and osmoregulatory regulation during trout smolting, which might provide new insights into seawater aquaculture of salmonid species.

Digestive characteristics and blood chemistry profile of triploid rainbow trout Oncorhynchus mykiss: influence of body size and seasonal variation

Two experiments were conducted to evaluate the effects of body size and seasonal variation on organ indexes, digestive enzymes and plasma biochemistry parameters of triploid rainbow trout. Results in experiment 1 showed that compared with small fish, large fish had significantly (P < 0.05) higher values of organ indexes, higher plasma nutrient contents as well as higher specific activities of lipase in pyloric caeca and amylase in the intestine. Results in experiment 2 showed that fish in spring or winter had greater intestine length as well as lower specific activities of protease and lipase in pyloric caeca (P < 0.05). Fish in autumn had the highest specific activities of acid protease in the stomach and alkaline protease in pyloric caeca, lipase in pyloric caeca as well as nutrient contents in plasma, while fish in summer had the lowest liver and viscera weight as well as plasma nutrient contents. Based on data of organ indexes, digestive enzymes and plasma biochemistry parameters, the physiological status of triploid rainbow trout were affected by fish size and seasonal variation. Normal reference ranges of organ indexes and plasma biochemical parameters of triploid rainbow trout were preliminarily established, which are partly different from diploid trout.

Oxidative effect of l-carnitine on energy metabolism in diploid and triploid rainbow trout (Oncorhynchus mykiss): impact on metabolites

l-Carnitine plays a key role in the regulation of energy metabolism and growth in fish. The aim of this study was to determine the effects of dietary l-carnitine levels on carnitine homeostasis and energy metabolism in diploid and triploid trout (Oncorhynchus mykiss). Diploid and triploid trout (29.5 ± 0.6 and 31.8 ± 0.5 g, respectively) were fed with three diets supplemented with 15, 200 or 530 mg l-carnitine/kg, respectively, for 56 days. Compared to 15 mg l-carnitine, total carnitine content increased in the liver by 182% in diploid and by 154% in triploid trout fed 530 mg l-carnitine. In muscle, total carnitine content increased by 60 and 73% in diploid and by 34 and 75% in triploid with the increase in dietary l-carnitine levels. l-Carnitine caused no significant change in the plasma concentrations of metabolites like proteins (ammonia, urea and protein), lipid (triglycerides), carbohydrate (glucose, lactate) and enzyme activities (lipase, lactate, alanine transaminase, lactic acid dehydrogenase). Triploid trout had significantly lower plasma ammonia (P = 0.003), lipase (P = 0.005) and triiodothyronine (T3; P = 0.003) levels than diploid trout. In conclusion, ploidy significantly affected the energy metabolism in rainbow trout, dietary l-carnitine levels altered the l-carnitine homeostasis, but not influence nutritional metabolism.

Expression of cytochrome genes during the early gonadal development in triploid female rainbow trout Oncorhynchus mykiss

PDF HTML阅读 XML下载 导出引用 引用提醒 三倍体雌性虹鳟性腺发育阶段细胞色素相关基因的表达 DOI: 作者: 作者单位: 1. 上海海洋大学 水产科学国家级实验教学示范中心, 上海 201306;2. 中国水产科学研究院黑龙江水产研究所, 黑龙江 哈尔滨 150070;3. 上海海洋大学 水产动物遗传育种中心上海市协同创新中心, 上海 201306 作者简介: 相福生(1990-),男,硕士研究生,主要从事冷水鱼育种与繁殖的研究.E-mail:fishxiangfs@163.com 通讯作者: 中图分类号: S917 基金项目: 现代农业产业技术体系专项资金项目（CARS-46）；中国水产科学研究院基本科研业务费项目（2018HY-ZD03）；黑龙江省自然科学基金面上项目（C2016069）. Expression of cytochrome genes during the early gonadal development in triploid female rainbow trout Oncorhynchus mykiss Author: Affiliation: 1. National Demonstration Center for Experimental Fisheries Science Education;Shanghai Ocean University, Shanghai 201306, China;2. Heilongjiang Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin 150070, China;3. Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding;Shanghai Ocean University, Shanghai 201306, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:等细胞色素相关基因能够调节硬骨鱼类性类固醇的合成，对性腺发育和性别决定产生影响。本研究以全雌三倍体虹鳟（）为研究对象，正常雌性二倍体虹鳟为对照，选取31~68 dpf（days post fertilization）时间段的虹鳟仔鱼脑组织，采用qRT-PCR和酶联免疫的方法研究以上几种基因的表达状况和脑芳香化酶的活性变化，以期探明导致三倍体雌性虹鳟性腺发育异常的关键原因。qRT-PCR结果显示，二倍体中在30~50 dpf时表达量上调并且维持在较稳定水平，但50~56 dpf时表达量逐渐下调，之后56~68 dpf表达量持续上调；三倍体中表达量在30~35 dpf开始上调，35~47 dpf逐渐下调，47~55 dpf开始第二次上调，之后维持在较稳定水平直至68 dpf，但三倍体表达量在34 dpf出现峰值，三倍体表达量在33~42 dpf时维持在较高水平，在38 dpf时出现高峰；三倍体在37 dpf出现峰值，之后开始下调；三倍体在40 dpf出现峰值，之后逐渐下调，但三倍体的表达量在35~46 dpf时逐渐上升，在45 dpf时达到高峰之后直至69 dpf逐渐下降，并且维持在较为平稳的水平上；但是在相同的实验条件下未检测到同一时期三倍体P<0.05）高于三倍体虹鳟，尤其在45~50 dpf时，该酶活性分别较三倍体的高1.15倍和1.12倍。以上结果表明三倍体虹鳟早期性腺发育迟缓的原因之一是等基因的表达晚于二倍体，且表达量低于二倍体，造成雌二醇不能正常合成，最终导致性腺发育迟缓。 Abstract:The genes play an important role in the steroidogenesis and gonadal differentiation of teleosts. Therefore, in this study, we chose triploid and diploid rainbow trouts () at 31-68 days post fertilization (dpf) cultured in the same environment as object. In this study, triploid rainbow trouts were used as object and diploid rainbow trouts were used as controls to evaluate the expression of genes and the activity of CYP19A1B enzyme in the brain of rainbow trout. The real-time polymerase chain reaction results showed that the expression of in the diploid rainbow trout was up-regulated during 30-50 dpf and maintained a stable level during this period. Subsequently, during 50-56 dpf, the expression was down-regulated; during 56-68 dpf, the expression was up-regulated again. The expression of in the triploid rainbow trout was up-regulated during 30-35 dpf, down-regulated during 35-47 dpf, and then upregulated during 47-55 dpf; thereafter, until 68 dpf, the expression was maintained at a stable level. The expression of in diploid rainbow trout peaked at 34 dpf and in triploid rainbow trout peaked at 38 dpf. The expression of in the diploid rainbow trout was maintained at a high level during 33-42 dpf and its expression peaked at 38 dpf. The expression of in the triploid rainbow trout was high during 47-59 dpf and peaked at 49 dpf. The expression of in diploid rainbow trout peaked at 37 dpf, and then the expression was down-regulated. In the triploid rainbow trout, the peak value was recorded at 40 dpf, and then the expression was down-regulated, but the expression of in the triploid rainbow trout was lower than that in the diploid rainbow at the same period. The expression of in the diploid rainbow trout was up-regulated at 35-46 dpf and the peak value was recorded at 45 dpf, and then the expression was down-regulated until 69 dpf. However, under the same experimental conditions, the expression of in the triploid rainbow trout was not detected. The results of enzyme-linked immunosorbent assay demonstrated that at 40 dpf, the activity of CYP19A1B enzyme in the diploid and triploid rainbow trout peaked, but during 40-60 dpf, the activity of CYP19A1B enzyme in the diploid rainbow trout was significantly higher than that in the triploid rainbow trout; especially at 45 dpf and 50 dpf, the activity of this enzyme in the diploid trout was 1.15 and 1.12 times higher than that in the triploid trout, respectively. The results suggest that one of the reasons for early gonadal differentiation delay in triploid rainbow trout is the expression of is lower and later than those in the diploid rainbow trout. Moreover, estradiol cannot be synthesized normally in triploid rainbow trout, and therefore, gonadal differentiation is delayed. 参考文献 相似文献 引证文献

Differential Expression of the &lt;i&gt;Dmrt1&lt;/i&gt; Gene from Ovaries of Diploid and Triploid Rainbow Trout (&lt;i&gt;Oncorhynchus mykiss&lt;/i&gt;)

Reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the differential expression of the Dmrt1 gene in ovaries of diploid and triploid rainbow trout (Oncorhynchus mykiss) 10 and 20 months post-hatch. At 10 months post-hatch there was little relative difference in the expression of the Dmrt1 gene between triploid and diploid trout. However, at 20 months the expression of the Dmrt1 gene in triploids was more than 14 times higher than in diploids. Dmrt1 expression from 10 to 20 months suggests masculinization of the ovaries, which may be virilescent in triploid females at the later development phase (20 months). This study provides molecular evidence supporting the general claims that ovaries of female triploid rainbow trout do not develop normally resulting in sterility.

Flesh characteristics of pan-size triploid and diploid rainbow trout (&amp;lt;i&amp;gt;Oncorhynchus mykiss&amp;lt;/i&amp;gt;) reared in a commercial fish farm

Abstract. Sexual maturation of rainbow trout during production has a negative effect on the slaughter yields and flesh quality. Induction of triploidy is a method to prevent the development of fertile trout. In many investigations sexually mature triploid and diploid rainbow trout had been compared. In the present study the slaughter characteristics and flesh quality of female immature diploid and triploid rainbow trout reared up to 66 and 75 weeks (pan-size-format) were compared. Considering the age the old fish had significantly higher body and fillet weights accompanied with larger muscle fibres. The fillets of the old trout were brighter and redder, had a reduced water-holding capacity (WHC) and contained more fat and protein. With regard to the ploidy status the triploid trout had higher body and fillet weights and larger muscle fibres. The fillets of the triploid fish were brighter, had a reduced WHC and lower fat contents. With regard to the age-ploidy status interaction the young and old triploid trout had better growth characteristics but the WHC and the fillet fat concentration was reduced in these animals. The colour values were inconsistent. The pH and electrical conductivity values indicated no higher pre- or peri-mortal stress and/or different stress susceptibility of the investigated young as well as old triploid and diploid trout. In conclusion, it could be suggested that induction of triploidy positively influences body and fillet development mainly by muscle fibre hypertrophy, but the triploid fillets showed slightly worse flesh characteristics (Brightness, WHC).

Routine Use of Sterile Fish in Salmonid Sport Fisheries

Since 1997, Idaho Department of Fish and Game hatchery and research personnel have worked cooperatively to develop a sterile trout program with the primary goals of protecting the genetic integrity of native stocks while continuing to supply hatchery-reared trout for harvest-oriented anglers. Results of recent field evaluations of sterile rainbow trout (Oncorhynchus mykiss) demonstrate that they provide recreational fisheries of equal or superior quality to normal diploid fish when stocked as catchables in streams or as fingerlings in productive lentic systems. Our preliminary evaluations suggest that use of sterile trout in high mountain lakes may require stocking adjustments or may eventually prove problematic because of lower survival rates. Sterile trout eggs can be readily purchased from commercial sources or produced from agency broodstocks with nominal equipment and manpower costs. To gain a better understanding of sterile fish use by other agencies, we conducted a U.S. state phone survey during 2005, and posed questions to fisheries administrators regarding their stocking practices. Officials from 10 states indicated that they had ongoing programs for sterilizing hatchery salmonids. Eight of these programs were located in the western United States, while only two occurred east of the Mississippi River. The presence of native species either listed under the Endangered Species Act or petitioned to be listed has greatly influenced agency interest in sterile fish programs. Regardless of native species status, we believe that expansion of sterile hatchery trout programs can improve conservation and management programs in other states. Despite our obvious enthusiasm for use of sterile trout in recreational fisheries, they are not a panacea, and we call for additional evaluations with normal diploid trout in states developing such programs.

Differences in sexual maturity and fall emigration between diploid and triploid brook trout (Salvelinus fontinalis) in an Adirondack lake

High levels of emigration coincident with maturity and spawning have been reported from brook trout (Salvelinus fontinalis) populations in Adirondack lakes. These lakes typically had few spawning areas and required stocking to maintain populations. We compared diploid and triploid brook trout to identify differences in gonadal development and emigration. Age 1 + and 2 + diploid and triploid brook trout held in captivity were examined internally for gonadal development. More diploid trout were mature than triploid fish (p &lt; 0.01). Of triploid brook trout that matured, all were males. Yearling diploid and triploid brook trout were also stocked into a lake that had an outlet but no spawning areas. During the fall spawning season, only mature yearling triploid males, diploid males, and diploid females were caught in an outlet trap. No triploid females were caught. A greater proportion of diploids emigrated than triploids (p &lt; 0.01). Triploidy in females arrested emigration by preventing sexual maturation. Triploid male brook trout should not be stocked because they can pose a reproductive risk to wild brook trout downstream from lakes. Stocking triploid females could reducefall emigration and thus reduce the loss of catchable brook trout from Adirondack lakes with outlets and little spawning habitat.

Non-specific Defense Activities of Triploid Rainbow Trout.

Triploid rainbow trout Oncorhynchus mykiss were compared with diploid trout in complement activity monitored by hemolytic and bactericidal activities, and in neutrophil activity by visual phagocytosis and luminol-dependent chemiluminescence.No significant differences were detected in complement activity and neutrophil activity between diploid and triploid trout. These results indicate that non-specific defense activities of triploid trout are similar to those of diploid trout, and that the triploidy does not fundamentally affect the susceptibility of the fish to diseases.

Use of diploid and triploid trout erythrocytes as internal standards in flow cytometry

DNA content determination requires the use of standards. Vindelov has shown the need to use two standards. Chicken and trout erythrocytes are commonly used, but they are not ideal standards. On the one hand, their DNA contents rarely frame the studied sample DNA content, and, on the other hand, as their base compositions are different in terms of A + T/G + C, their relative indices change according to the stains used. Use of triploid trout erythrocytes instead of chicken erythrocytes allows elimination of these two drawbacks; however, diploid trout must be differentiated from triploid trout. The present paper shows that an anatomic malformation is found with the triploid trout and so justifies the use of paired diploid and triploid trout as standards to measure nuclear DNA content.

Polyploidy Induced by Heat Shock in Rainbow Trout

Polyploidy was induced in rainbow trout Salmo gairdneri when fertilized eggs were immersed in 36 C water for 1 minute. Triploids were produced if the eggs were treated 10 minutes after fertilization; tetraploids were produced by treatments 5 hours after fertilization. Sterile triploid trout and salmon potentially could grow and survive better than normal fish at sexual maturation. Heat-shock techniques also should be useful in the production of gynogenetic diploid trout and salmon for biological studies and breeding programs.