三角鲂(♀)×翘嘴红鲌(♂)F1及其亲本肌肉成分与必需氨基酸组成模式的比较分析

为比较研究三角鲂、翘嘴红鲌及其杂交F1代的肌肉营养价值的差异,并对杂交种进行营养价值评价,本试验对三种鱼类一般营养成分、氨基酸组成、含量及氨基酸评价等指标进行了比较分析。结果显示,杂交种的粗蛋白含量高于亲本,但粗脂肪含量低于亲本;杂交种的氨基酸总量及必需氨基酸含量都高于亲本;氨基酸指数介于两个亲本之间,且在45%以上;杂交种的氨基酸评分(AAS)大于1.0,化学评分(CS)评级大于0.5。综合分析结果表明,三角鲂(♀)×翘嘴红鲌(♂)F1是一种营养价值较高的优质鱼类,其必需氨基酸组成与翘嘴红鲌比较接近。     

(团头鲂♀×翘嘴红鲌♂)杂种F_1的含肉率、肌肉营养成分及氨基酸含量

采用国标生化分析方法对(团头鲂♀×翘嘴红鲌♂)杂种F1的含肉率、肌肉营养成分(蛋白质、粗脂肪、水分、灰分)以及蛋白质的18种氨基酸进行了测定分析,结果表明该杂种的含肉率平均为84.38%、蛋白质含量为19.99%、脂肪含量为1.35%、灰分含量为1.40%、水分为77.19%、总氨基酸含量为18.59%,氨基酸含量中许多指标明显高于作为对比的几种经济鱼类。因此杂种F1可考虑作为一个新的养殖对象进行开发。     

杂交翘嘴鲂

正杂交翘嘴鲂(品种登记号:GS-02-003-2014)由湖南师范大学鱼类发育生物学研究室选育。通过近十年的团头鲂与翘嘴红鲌的远缘杂交研究,科研团队首先成功研制出二倍体鲂鲌品系;然后通过大量的正反交研究,选定用该品系的F1雌性与雄性团头鲂回交,最终形成了具有多种优良性状的新品种-杂交翘嘴鲂。     

杂交翘嘴鲂

正育种单位:湖南师范大学品种简介:该品种是以湘江流域采捕后分别经6代群体选育的团头鲂选育品系♀和翘嘴红鲌选育品系♂杂交获得的子一代二倍体鲂鲌为母本,以团头鲂选育品系为父本,杂交获得的F5,即为杂交翘嘴鲂。遗传了团头鲂的草食性,肉质鲜嫩;在相同养殖条件下,1龄鱼平     

三角鲂(♀)×翘嘴鲌(♂)杂交F1的生长性能及形态差异

为探讨三角鲂、翘嘴鲌及其杂交子代的生长性能与形态差异,本研究开展了广东东江三角鲂(MT)与长江水系翘嘴鲌(CA)远缘杂交实验,获得了三角鲂♀×翘嘴鲌♂新型鲂鲌杂交F1优良组合。以团头鲂(MA)♀×翘嘴鲌♂杂交F1、三角鲂、翘嘴鲌、团头鲂自交子代4个群体为对照,比较分析了MT♀×CA♂杂交F1的生长性能及形态差异。结果显示,(1)土池同池生长性能在1龄时,MT♀×CA♂、MA♀×CA♂表现出显著的超父本CA杂种优势;2龄时,MT♀×CA♂、MA♀×CA♂表现出显著的超双亲生长优势;3龄时,MT♀×CA♂不仅具显著的超双亲生长优势,且体质量也显著高于MA♀×CA♂。(2)MT♀×CA♂的可数和可量性状多数表现为中间型。可数性状的分析结果显示,MT♀×CA♂臀鳍等多个性状介于父母本之间,平均杂种指数为65.00,接近中间值,略偏向于父本CA。可量性状表明MT♀×CA♂有7个性状分别与父母本有显著性差异,平均杂种指数为51.61,接近理想的中间值。(3)聚类分析显示鲂鲌杂种MT♀×CA♂和MA♀×CA♂聚为一支,MT和MA聚为一支,然后这两支汇聚后与CA聚为一支。主成分分析得到累计贡献率达56.02%的3个主成分,反映了鱼体高、躯干、头部和尾部的形态变异;通过构建5个群体的判别函数进行判别分析,判别准确率为87.1%~100.0%。研究表明,三角鲂(♀)×翘嘴鲌(♂)F1杂种表现出生长快、形态优等优良性状,有望进一步培育成为优良鲂鲌杂交新品种。     

野生与养殖翘嘴鲌品质的比较研究

为研究野生和养殖翘嘴鲌(Culter albunus)之间肉质指标的差异,对野生和人工养殖翘嘴鲌的基本营养成分、氨基酸组成、脂肪酸组成、质地特性、体色等指标进行了分析。结果显示:野生翘嘴鲌肌肉蛋白质含量(19.84%)及灰分含量(0.27%)均显著高于养殖翘嘴鲌(13.29%和0.21%),但是脂肪含量(4.34%)和水分含量(71.84%)均显著低于养殖翘嘴鲌(5.51%和78.61%);野生翘嘴鲌氨基酸总量和鲜味氨基酸总量分别较养殖翘嘴鲌高出11.36%和11.16%;野生和养殖翘嘴鲌的氨基酸评价指数(EAAI)分别为100.51和98.13;养殖翘嘴鲌肌肉单不饱和脂肪酸(MUFA)含量及n-3/n-6系列多不饱和脂肪酸(PUFA)的比值显著高于野生翘嘴鲌,但是饱和脂肪酸(SFA)含量显著低于野生翘嘴鲌。此外,野生翘嘴鲌背部和腹部红色值、黄色值及侧线部红色值均显著高于养殖翘嘴鲌;野生翘嘴鲌的肌肉硬度和内聚性显著高于养殖翘嘴鲌;养殖翘嘴鲌的肌肉滴水损失、蒸煮损失及pH值显著高于野生翘嘴鲌。结果表明,野生翘嘴鲌的营养价值更高、鲜味更好,而养殖翘嘴鲌在脂肪酸组成方面更具优势。     

团头鲂(♀)× 鲌 翘嘴 (♂)杂交后代的遗传特征及生长差异

本研究利用团头鲂(Megalobrama amblycephala)‘浦江1号’(♀)×翘嘴鲌(Erythroculter ilishaeformis)(♂)进行属间人工杂交,获得了遗传背景不同的杂交子代。结果显示,团头鲂‘浦江1号’(♀)×翘嘴鲌(♂)杂交子代的受精率和孵化率均很高,分别为90.0%和80.6%。鲂鲌杂交子代的体型有两种,其中,96.2%的后代为鲂鲌中间型体型(杂种A型),另外还存在3.8%的后代体型与母本团头鲂‘浦江1号’相近(杂种B型)。经Partec流式细胞仪测定得出,鲂鲌杂种A型个体DNA含量与母本、父本相同,表明其为二倍体。2个特异性微卫星位点(TTF6和TTF10)分析显示,杂种A型个体从其父母本中各获得了一套遗传物质,证实其为二倍体杂交种,鲂鲌杂种B型的带型则与母本完全一致,为雌核发育后代。土池同池生长性能分析显示,鲂鲌中间型个体的生长速度显著快于团头鲂‘浦江1号’和翘嘴鲌,表现出明显的超亲生长优势。本研究为鲂鲌杂交新品系的建立奠定了基础,另外,鲂鲌杂交自发产生雌核发育后代便于团头鲂纯系的构建。     

团头鲂(♀)×翘嘴鲌(♂)杂交后代的遗传特征及生长差异

本研究利用团头鲂(Megalobrama amblycephala)‘浦江1号’(♀)×翘嘴鲌(Erythroculter ilishaeformis)(♂)进行属间人工杂交,获得了遗传背景不同的杂交子代。结果显示,团头鲂‘浦江1号’(♀)×翘嘴鲌(♂)杂交子代的受精率和孵化率均很高,分别为90.0%和80.6%。鲂鲌杂交子代的体型有两种,其中,96.2%的后代为鲂鲌中间型体型(杂种A型),另外还存在3.8%的后代体型与母本团头鲂‘浦江1号’相近(杂种B型)。经Partec流式细胞仪测定得出,鲂鲌杂种A型个体DNA含量与母本、父本相同,表明其为二倍体。2个特异性微卫星位点(TTF6和TTF10)分析显示,杂种A型个体从其父母本中各获得了一套遗传物质,证实其为二倍体杂交种,鲂鲌杂种B型的带型则与母本完全一致,为雌核发育后代。土池同池生长性能分析显示,鲂鲌中间型个体的生长速度显著快于团头鲂‘浦江1号’和翘嘴鲌,表现出明显的超亲生长优势。本研究为鲂鲌杂交新品系的建立奠定了基础,另外,鲂鲌杂交自发产生雌核发育后代便于团头鲂纯系的构建。     

基于细胞色素b基因序列的鲌亚科鱼类系统发育研究

采用特异性引物PCR扩增获得了鲌亚科7属10种鱼类细胞色素b基因的全长序列,初步构建了鲌亚科鱼类的系统发育关系。NJ树和MP树一致表明,鲌亚科鱼类种内所有个体均单独聚群,支持率高;同一属内,除蒙古鲌(Culter mogolicus mongolicus)未能与同属的翘嘴鲌(Culter alburnus)、青梢鲌(Culter dabryi dabryi)单独聚为一支外,团头鲂(Megalobrama amblycephala)与三角鲂(Megalobrama terminal)、翘嘴鲌与青梢鲌均为姐妹种。NJ、MP树显示鲌亚科鱼类属间关系的支持率都较低,鲂属(Megalobrama)与鳊属(Parabramis)间、鲌属(Culter)与原鲌属(Cultrichthys)间、细鳊属(Rasborinus)与半属(Hemiculterella)、属(Hemiculter)间有较近的亲缘关系,在系统演化关系上,细鳊属、半属、依氏鱼属(Ishikauia)较为原始,鲌属与原鲌属、鲂属与鳊属互为姐妹群,为较特化群。     

不同水系翘嘴鲌群体肌肉营养成分分析与评价

为评估不同水系翘嘴鲌(Culter alburnus)肌肉营养成分的差异,对长江上游、长江下游、黑龙江和淮河等4个水系翘嘴鲌肌肉的氨基酸和脂肪酸营养指标进行了比较分析。结果表明:在所检测出的18种氨基酸中,4个水系翘嘴鲌的甘氨酸和苯丙氨酸含量存在显著差异(P<0.05),其中黑龙江水系均为最高,而其他16种氨基酸含量在4个水系间不存在显著差异(P>0.05)。黑龙江水系翘嘴鲌肌肉中的必需氨基酸含量(EAA)亦为最高,但与另外3个水系的差异不显著(P>0.05)。根据氨基酸评分和化学评分进行营养评价的结果表明,4个水系翘嘴鲌的第一、第二限制性氨基酸均为蛋氨酸+胱氨酸和缬氨酸,其必需氨基酸指数(EAAI)在81.27~82.43。淮河水系翘嘴鲌肌肉中的单不饱和脂肪酸含量最低,而黑龙江水系翘嘴鲌肌肉中的二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)含量显著高于长江上游和下游水系(P<0.05)。综合来看,4个水系翘嘴鲌肌肉的营养成分基本一致,都具有均衡的营养价值,可满足人类的营养需求,均为优质的蛋白质来源,其中黑龙江水系翘嘴鲌在氨基酸和脂肪酸层面具有更高的食用价值。     

甘草次酸对团头鲂生长、脂肪沉积与抗氧化功能的影响

为探讨甘草次酸对团头鲂生长、脂肪沉积和抗氧化功能的影响,选取均体质量为(15.63±0.04)g的团头鲂幼鱼420尾,随机分在15个网箱中,分别以甘草次酸水平为0、0.15、0.30、0.45和0.60 g/kg的5种饲料投喂8周。结果发现,饲料添加甘草次酸对团头鲂增重率、特定生长率、饵料系数没有显著影响(P0.05)。甘草次酸可以显著降低实验鱼脏体比、肝体比、腹脂率及肝脏脂肪含量(P0.05),但对全鱼体组成和肌肉脂肪含量无显著影响(P0.05)。比对血浆脂肪代谢酶可见,0.30~0.60 g/kg甘草次酸添加组血浆总胆固醇含量较对照组显著下降(P0.05);而甘油三酯、游离脂肪酸和高密度脂蛋白胆固醇含量无显著变化(P0.05)。肝脏中脂蛋白酯酶、肝酯酶和总酯酶活性在添加甘草次酸后显著降低(P0.05);0.30~0.60 g/kg甘草次酸添加组脂肪酶活性显著高于其他各组(P0.05)。饲料添加甘草次酸可以显著提高肝脏超氧化物歧化酶活性和还原型谷胱甘肽含量,降低丙二醛含量(P0.05)。研究表明,饲料中添加0.30~0.45 g/kg甘草次酸时,显著降低了团头鲂内脏团的脂肪沉积,改善了鱼体脂肪分布,这可能是由于甘草次酸加强脂解作用,提高脂肪代谢酶活性导致的;饲料中添加甘草次酸也可显著提高团头鲂的抗氧化能力。     

Production of interploid triploids by 4n × 2n blunt snout bream (Megalobrama amblycephala. Yih) and their first performance data

Positive and negative interploid triploids of blunt snout bream (Megalobrama amblycephala) were produced by reciprocal crossing autotetraploids with diploids. Fertilization and hatching rate of negative interploid triploid, 2n♀× 4n♂, at different reproductive ages was similar to that of control, but higher than that of positive interploid triploid, 4n♀× 2n♂. Additionally, the development rate of embryos of the positive interploid triploid, 4n♀× 2n♂, was slower than that of control and the negative interploid triploid, 2n♀× 4n♂. Gonad growth of the positive and negative interploid 3n was significantly (P<0.01) affected by parents, and spawning could not be induced both in females and males at the 2+ age. The negative interploid 3n (2n♀× 4n♂) had a significantly higher survival rate than the positive interploid 3n (4n♀× 2n♂), but close to the level of the control (P<0.05). The daily growth rate of the negative interploid 3n was similar to that of the good breed ‘Pujiang No. 1’ blunt snout bream (2n) during the early life stages.     

Effects of dietary linolenic acid on growth,fatty acid composition,immune function and antioxidant status of juvenile blunt snout bream,Megalobrama amblycephala

A nine‐week feeding trial was performed to determine the dietary linolenic acid (LNA; 18:3n–3) requirements of juvenile blunt snout bream. Six iso‐nitrogenous, semi‐purified diets were prepared with different concentrations of LNA (0–25 g/kg). Dietary LNA had no significant effects on survival rate. However, final fish weight, weight gain (WG), specific growth rate (SGR) and feed efficiency ratio (FER) increased with increasing dietary LNA concentrations up to 20 g/kg. Dietary LNA increased muscle LNA and total n‐3 polyunsaturated fatty acid (PUFA) contents, but decreased total saturated fatty acid content. Fish fed 20 g/kg LNA had the highest plasma alkaline phosphatase activity, total protein, albumin and white blood cell count levels. Additionally, fish fed 20 g/kg LNA had higher triglyceride levels than control fish. Plasma glucose increased with increasing dietary LNA concentrations. Superoxide dismutase and glutathione peroxidase activities significantly increased with increasing dietary LNA concentrations up to 15 g/kg. Based on SGR and FER, the optimal dietary LNA requirements of juvenile blunt snout bream were 17.5 and 15.6 g/kg respectively.     

饲料不同淀粉水平对团头鲂成鱼生长性能、消化酶活性及肌肉成分的影响

为探讨饲料淀粉水平对团头鲂成鱼生长、消化酶活性和肌肉成分的影响,选用初始均重为(161±2.7)g的团头鲂成鱼360尾,随机分成6组(每组3个重复),分别投喂含淀粉17.1%、21.8%、26.4%、32.0%、36.3%和41.9%的等氮等脂饲料9周。结果发现,团头鲂成鱼成活率和特定生长率不受饲料淀粉水平影响,但饲料添加适量淀粉能提高饲料和蛋白利用率,淀粉水平对肝脏和肠道中的总蛋白酶和纤维素酶活性不产生影响,却显著影响淀粉酶活性。肝体比、肝糖原和肌肉粗脂肪含量随饲料淀粉含量的增加而显著增加,血清血糖、胆固醇和甘油三酯含量不受饲料淀粉水平的显著影响,饲料中添加过量淀粉显著降低了血清补体3和补体4含量。以蛋白质效率和饲料效率为评价指标,经折线模型回归分析,得到团头鲂成鱼饲料中淀粉的适宜添加量分别为饲料干重的34.1%和31.4%,但考虑到血清补体的活性,团头鲂成鱼日粮淀粉水平不应超过36.3%。     

Effect of dietary betaine on growth performance,antioxidant capacity and lipid metabolism in blunt snout bream fed a high-fat diet

An 8-week feeding experiment was conducted to determine the effect of dietary betaine levels on the growth performance, antioxidant capacity, and lipid metabolism in high-fat diet-fed blunt snout bream (Megalobrama amblycephala) with initial body weight 4.3 ± 0.1 g [mean ± SEM]. Five practical diets were formulated to contain normal-fat diet (NFD), high-fat diet (HFD), and high-fat diet with betaine addition (HFB) at difference levels (0.6, 1.2, 1.8%), respectively. The results showed that the highest final body weight (FBW), weight gain ratio (WGR), specific growth rate (SGR), condition factor (CF), and feed intake (FI) (P < 0.05) were obtained in fish fed 1.2% betaine supplementation, whereas feed conversion ratio (FCR) was significantly lower in the same group compared to others. Hepatosomatic index (HSI) and abdominal fat rate (AFR) were significantly high in fat group compared to the lowest in NDF and 1.2% betaine supplementation, while VSI and survival rate (SR) were not affected by dietary betaine supplementation. Significantly higher (P < 0.05), plasma total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), aspartate transaminase (AST), alanine transaminase (ALT), cortisol, and lower high-density lipoprotein (HDL) content were observed in HFD but were improved when supplemented with 1.2% betaine. In addition, increase in superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) in 1.2% betaine inclusion could reverse the increasing malondialdehyde (MDA) level induced by HFD. Based on the second-order polynomial analysis, the optimum growth of blunt snout bream was observed in fish fed HFD supplemented with 1.2% betaine. HFD upregulated fatty acid synthase messenger RNA (mRNA) expression and downregulated carnitine palmitoyltransferase 1, peroxisome proliferator-activated receptor α, and microsomal triglyceride transfer protein mRNA expression; nevertheless, 1.2% betaine supplementation significantly reversed these HFD-induced effects, implying suppression of fatty acid synthesis, β-oxidation, and lipid transport. This present study indicated that inclusion of betaine (1.2%) can significantly improve growth performance and antioxidant defenses, as well as reduce fatty acid synthesis and enhance mitochondrial β-oxidation and lipid transportation in high-fat diet-fed blunt snout bream, thus effectively alleviating fat accumulation in the liver by changing lipid metabolism.     

团头鲂核型与DNA含量分析研究

采用PHA体内培养法，取鱼体肾细胞用空气干燥法制备团头鲂染色体标本。经核型分析，团头鲂的核型为2n=48,26m 18sm 4st，臂数（NF）为92。用流式细胞仪测量外周血红血球细胞核的DNA含量为2．66pg/N。实验结果分析表明团头舫染色体数及DNA含量是稳定的，其核型公式与有关文献的报道略有差异。     

Molecular characterization and identification of facilitative glucose transporter 2 (GLUT2) and its expression and of the related glycometabolism enzymes in response to different starch levels in blunt snout bream (<Emphasis Type="Italic">Megalobrama amblycephala</Emphasis>)

Facilitative glucose transporters (GLUT) are transmembrane transporters involved in glucose transport across the plasma membrane. In this study, blunt snout bream GLUT2 gene was cloned, and its expression in various tissues and in liver in response to diets with different carbohydrate levels (17.1; 21.8; 26.4; 32.0; 36.3; and 41.9% of dry matter). Blunt snout bream GLUT2 was also characterized. A full-length cDNA fragment of 2577 bp was cloned, which contains a 5′-untranslated region (UTR) of 73 bp, a 3′-UTR of 992 bp, and an open reading frame of 1512 bp that encodes a polypeptide of 503 amino acids with predicted molecular mass of 55.046 kDa and theoretical isoelectric point was 7.52. The predicted GLUT2 protein has 12 transmembrane domains between amino acid residues at 7–29; 71–93; 106–123; 133–155; 168–190; 195–217; 282–301; 316–338; 345–367; 377–399; 412–434; and 438–460. Besides, the conservative structure domains located at 12–477 amino acids belong to the sugar porter family which is the major facilitator superfamily (MFS) of transporters. Blunt snout bream GLUT2 had the high degree of sequence identity to four GLUT2s from zebrafish, chicken, human, and mouse, with 91, 63, 57, and 54% identity, respectively. Quantitative real-time (qRT) PCR assays revealed that GLUT2 expression was high in the liver, intestine, and kidney; highest in the liver and was regulated by carbohydrate intake. Compared with the control group (17.1%), fed by 3 h with higher starch levels (32.0; 36.3; and 41.9%), increased plasma glucose levels and glycemic level went back to basal by 24 h after treatment. Furthermore, higher dietary starch levels significantly increase GLUT2, glucokinase (GK), and pyruvate kinase (PK) expression and concurrently decrease phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6P) mRNA levels (P?<?0.05), and these changes were also back to basal levels after 24 h of any dietary treatment. These results indicate that the blunt snout bream is able to regulate their ability to metabolize glucose by improving GLUT2, GK, and PK expression levels and decreasing PEPCK and G6P expression levels.     

Effects of dietary vitamin E supplementation on growth performance,fatty acid composition,lipid peroxidation and peroxisome proliferator-activated receptors (PPAR) expressions in juvenile blunt snout bream <Emphasis Type="Italic">Megalobrama amblycephala</Emphasis>

A 9-week feeding experiment was conducted to evaluate the effects of dietary vitamin E (VE) supplementation on growth performance, liver fatty acid composition, lipid peroxidation and peroxisome proliferator-activated receptors (PPAR) genes expressions in blunt snout bream juveniles. Fish (average initial weight: 0.59 g) were fed diet supplemented with 0, 50, 100, 300 and 500 mg α-tocopherol acetate/kg in triplicates, which were found to, respectively, contain 11.2, 56.3, 114.6, 306.5 and 588.4 mg α-tocopherol/kg diet. Results showed that final weight, body weight gain and specific growth rate significantly increased with increasing dietary VE supplemented level from 11.2 to 56.3 mg/kg. When the broken-line model was employed to estimate the adequate requirement of vitamin E based on body weight gain, the optimal level was 55.5 mg/kg in diet. Hepatosomatic index value significantly decreased with incremental dietary VE levels. However, liver VE concentration showed a direct relationship with the dietary VE level. The percentages of 20:5n-3, 22:6n-3 and total n-3 long chain polyunsaturated fatty acids in liver increased with increasing dietary VE supplementation. Meanwhile, the expressions of PPAR-α, PPAR-β and PPAR-γ in liver were down-regulated by supplementation of dietary VE level from 56.3 to 588.4 mg/kg. In conclusion, supplementation of more than 55.5 mg/kg vitamin E may improve growth and increase n-3 LC-PUFA content in blunt snout bream, which is beneficial to human consumer.     

鲤、团头鲂精子生理生态特性的研究──Ⅲ．单糖和渗透压对精子活力的影响

作者观察了鲤、团头鲂精子在０（去离子水）－３００毫渗渗透压的Ｄ－半乳糖，Ｄ－葡萄糖和Ｄ－果糖溶液中的活动情况。结果表明，在这三种单糖溶液里，鲤、团头鲂精子活动的变化规律是一致的。精子快速运动和寿命的时间是以在Ｄ－半乳糖溶液中为最长。这两种鱼精子对这三种单糖的吸收、利用存在差别。