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551.
An experiment was conducted to study the effect of supplementing catfish (Pangasianodon hypophthalmus) with turmeric (Curcuma longa) on the vitellogenic capacity of the liver as a new method to improve reproductive performance in oviparous animals. The experimental catfish were assigned to a completely randomized design consisting of four doses of supplemental turmeric (0, 1.2, 2.4 and 4.8 g/kg feed) with 10 catfish with body weights ranging from 2 to 4 kg in each group. Blood samples were collected on days 0, 14, 28, 42 and 56 of turmeric supplementation to measure the concentrations of plasma oestradiol‐17ß and vitellogenin. The weights of the body, gonads and liver were measured on days 0, 28 and 56. The fecundities of the catfish were measured on days 28 and 56 of turmeric supplementation, and egg diameters were measured on days 28 and 42. The results showed that catfish supplemented with turmeric at a dose of 2.4 or 4.8 g/kg feed had higher growth rates, higher plasma oestradiol‐17β and vitellogenin concentrations, and higher gonad somatic index values and egg diameters. This is the first report demonstrating that the hepatoprotective activity of the curcumin in turmeric could be used to improve both vitellogenin synthesis, which improves nutrient deposition in the ovulating eggs, and the reproductive performance of teleost fish and oviparous animals.  相似文献   
552.
通过CRISPR/Cas系统来构建miR-17-92基因簇的双切载体,研究结果表明:在miR-17-92基因簇的序列上找到了2个PAM(TGG和GGG)位点,从而得到了2个原间隔序列,设计合成基因簇双链crRNA;合成该片段并将其插入到p X260载体,使得在同一个载体上虽然只有一个g-RNA,但能够同时切割两个不同的靶位点;将该载体转染NIH3T3细胞验证切割效率,PCR结果和测序结果显示,所构建的CRISPR系统可以对基因片段进行有效切割。  相似文献   
553.
本研究以84头长白猪为试验材料,采用PCR-RFLP方法检测雌激素受体(estrogen receptor,ESR)和卵泡刺激素β(follicle-stimulating hormone β,FSHβ)基因的多态性,并进一步分析这2个基因多态位点及其合并基因型对繁殖性能的影响。结果表明,ESR和FSHβ基因均存在AA、AB和BB 3种基因型,2基因座均处于Hardy-Weinberg平衡状态;单基因效应分析结果表明,ESR基因AB基因型个体部分繁殖性能指标显著高于AA基因型,AB基因型为ESR基因的有利基因型。初产母猪FSHβ基因中BB、AA、AB基因型个体的所有繁殖性能指标均呈递增趋势,而经产母猪中AA基因型个体的性能指标较高,但是差异不显著(P>0.05);ESR与FSHβ的合并效应分析结果表明,基因聚合效应并不是各个基因效应的简单相加,在繁殖性能已经稳定的第3胎次,AA-AB型个体的繁殖性能显著低于其他合并基因型个体,表明该基因型为不利的合并基因型,故在长白猪选种选育过程中应优先考虑被淘汰。  相似文献   
554.
为研究弓形虫棒状体蛋白17(ROP17)基因的遗传变异,本研究以弓形虫RH株、PRU株和TgC7株为研究对象,首次PCR扩增了其ROP17基因部分序列,将PCR产物纯化后克隆到pMD18-T并测序。将测定的序列与网上下载的弓形虫VEG株、GT1株和ME49株相应序列进行比对,然后用Mega 5.0程序的NJ法和Puzzle 5.2程序的ML法构建系统发育树。结果表明,3株弓形虫分离株的ROP17基因部分序列长度均为1375 bp,A+T含量在49.53%~50.04%之间,3个虫株相应序列的变异碱基数皆小于20个,其变异率为2.3%,氨基酸序列变异率在0~6.11%之间。系统发育结果显示, ROP17基因部分序列能区分弓形虫基因Ⅰ型和Ⅱ型的虫株。本研究结果为进一步研究弓形虫ROP17基因的变异及研制弓形虫ROP17基因的亚单位疫苗提供了理论依据。  相似文献   
555.
在水温11.0~20.0℃、盐度35‰和pH值7.5的条件下,将初始平均体质量为3.46g的仿刺参(Aposticho-pusiaponicusSelenka)幼参放养在容水300L的塑料水槽中,A组投喂含90mg·kg-。β-胡萝卜素+60mg·kg-1维生素E(VE)的饲料,B组投喂含60mg·kg-1虾青素和60mg·kg-1VE的饲料,以不添加上述3种物质的基础饲料作对照(C组)。饲养80d后,将A、B,及C组幼参直接放人盐度(用淡水和海水或加入海水晶,配制成盐度为0、5、10、15、20、25、30、35、40、45,及50)、氨(用NH4Cl配制成氨浓度(Nn3-N)0、0.5、1.0、2.0、4.0、8.0,及10mg·L-1)、温度(0、4、10、15、20、25、30、35,及40℃)急剧变化的1500mL的白色聚乙烧杯中,每个处理3个重复,测定存活率和体腔液中SOD活力等指标。应激处理期间,不投喂,24h换水一次并吸出排泄物。96h后,盐度、氨处理组的仿刺参存活率高于对照组,存活仿刺参体腔液中SOD活力显著低于对照组(P〈0.05);但A、B组仿刺参在低温应激时,存活率与对照组差异不显著(P〉0.05)。结果表明:饲料中添加90mg·kg-1β-胡萝卜素+60mg·kg-1VE或60mg·kg-1虾青素+60mg·kg-1VE均能显著提高仿刺参对盐度和氨应激的抵抗能力(P〈0.05),但抗低温应激的效果不显著(P〉0.05)。  相似文献   
556.
A method was developed for the simultaneous determination of four kinds of estrogens(hexoestrol, diethylstilbestrol, estrone, and 17-beta-estradiol) in feed by gas chromatography-mass spectrometry(GC-MS). After the sample was extracted by ethyl ether and cleaned-up on HLB phase extraction column, four kinds of estrogens were derived and quantified in gas chromatographymass spectrometry. The results showed that the linear detectable ranged from 2.5 ng·mL~(-1) to 250 ng·mL~(-1) for hexoestrol and from 5 ng·mL~(-1) to 500 ng·mL~(-1) for three other estrogens with the correlation coefficients(R~2) were no less than 0.990. The recoveries were in the range of 76.34%-96.33% and the relative standard deviation was no more than 22.7%. The limits of quantitation(LOQ) for all analytics were between 10 ug·kg~(-1) and 20 ug·kg~(-1).The method was accurate and sensitive and could meet the actual requirements for the analyses of feed samples.  相似文献   
557.
甬优17是浙江省宁波市农业科学研究院作物研究所与宁波市种子有限公司用甬粳4号A和甬恢12配组选育成的粳型三系杂交水稻新品种,2014年通过福建省农作物品种审定。2014—2015年建瓯市东游镇引进甬优17号作单季晚稻和烟后稻种植,表现生育期适中,后期转色好,穗大粒多,丰产性好,米质较优等特点。总结了其特征特性及高产栽培技术。  相似文献   
558.
This study was performed to investigate the effects of 17β‐estradiol (ES) and 17α‐methyltestosterone (MT) on growth, development, survival, sex ratio and colour change in the electric blue hap (Sciaenochromis ahli Trewavas, 1935). The hormones were not supplemented to the control feed, while six other feeds were prepared by adding 20, 40 and 60 mg kg?1 17β‐ES or 20, 40 and 60 mg kg?1 17α‐MT to each, resulting in seven different feed treatments. Average live weight of the fish supplemented with these diets was 0.42 ± 0.04 g. At the end of the study, the highest weight gain was observed in fish fed 60 mg kg?1 17α‐MT group (2.62 ± 0.11 g) and the difference with the groups fed with 17β‐ES was found to be significant. All fish fed 17α‐MT were male, while the rates of feminization in fish fed 17β‐ES at 20, 40, 60 mg kg?1 were 91.11%, 88.88% and 93.33% respectively. Survival rates were respectively determined as 80%, 95.56%, 84.44%, 93.33%, 77.78%, 84.44% and 84.44% for the control, 20, 40, 60 mg kg?1 17β‐ES and 20, 40, 60 mg kg?1 17α‐MT treatments. The best colouration was achieved in the 17α‐MT groups (P < 0.05). The L* values varied between 32.98 ± 4.44 and 61.35 ± 2.19, a* values between ?7.06 ± 0.22 and ?3.42 ± 0.11, and b* values between ?7.74 ± 0.10 and 11.65 ± 0.03, while Chroma (C*) and Hue (H°ab) angle values varied between 7.54 ± 0.22 and 13.60 ± 0.01 and between 119.76 ± 0.05 and 239.73 ± 4.86. In conclusion, the 17α‐MT feeding was found to have a greater effect on the growth, feed conversion ratio, masculunization and pigmentation of the electric blue haps than the 17β‐ES treatment.  相似文献   
559.
A study was carried out to determine the effects of cold shock and 17α‐methyl testosterone hormone on growth in male morphotypes of giant freshwater prawn Macrobrachium rosenbergii. Juvenile males were exposed at 18 ± 0.25°C for 24 h with normal feed and cultured at 27 ± 0.7°C for 70 days as well as administrated feed with hormone separately at 400 mg kg?1 feed for the first 30 days of culture period (70 days). The growth (Mean ± SD) of male juveniles at harvest was closely homogenous in the cold shock (CLS) treated group; while it was heterogeneous in hormone‐treated (MH) and control (CO) groups. Although total body weight of blue claw (BC) males was not significantly different in the controls and the treatments, the 2nd pereiopods (claw) weight and length of the BC was significantly lower in CLS (0.52 ± 0.05 g, 10.02 ± 0.65 cm) than that in the CO (0.71 ± 0.16 g, 12.53 ± 0.57 cm) and MH (0.75 ± 0.08 g, 12.85 ± 1.18 cm) treatments. Survival of prawns was similar in treatments. The morphotypes of male prawn were significantly different with 59% of BC males with small‐sized claws in CLS and, 45% and 30% of BC males with large‐sized claws in MH and CO respectively. Cold shock adversely affected male morphotypes of the prawn so that numbers of BC males with small‐sized claw was the highest in CLS tank. However, the CLS treatment resulted in more uniform marketable prawns and suggested a high production of BC males in an all‐male culture system.  相似文献   
560.
本研究运用同源克隆技术和RACE技术克隆了栉江珧(Atrina pectinata)wnt4基因cDNA全长序列。该基因序列全长为1493 bp,其中开放阅读框1074 bp,编码由357个氨基酸组成的蛋白。氨基酸序列分析表明,栉江珧wnt4基因具有wnt家族保守结构域,与栉孔扇贝(Chlamys farreri)、海胆(Paracentrotus lividus)等物种具有高度的同源性。荧光定量PCR分析表明,wnt4基因表达具有广泛性和组织差异性,且与性别和性腺繁殖周期相关。wnt4基因表达量与性腺成熟度相关,并且整个繁殖周期卵巢表达量均显著高于精巢,说明wnt4基因参与了栉江珧两性性腺的发育,并在卵巢中发挥更重要的作用。不同发育阶段胚胎荧光定量分析表明,wnt4基因主要参与了栉江珧的早期胚胎发育。在胚胎发育早期(囊胚期和原肠期)wnt4基因的表达水平最高,是成体表达量的500倍;在担轮幼虫和D形幼虫期迅速下降,暗示wnt4基因可能在栉江珧早期发育阶段参与了某些器官的形成。17β-雌二醇诱导实验显示,17β-雌二醇可能通过反馈调节抑制卵巢wnt4基因表达(P0.05);短时间处理,17β-雌二醇能诱导精巢wnt4基因显著表达(P0.05)。  相似文献   
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