红鲫(♀)×鲤(♂)杂交鱼的胚胎染色体组倍性研究

红鲫属于鲤科、鲤亚科、鲫属,染色体数目为2n=100,核型为22m+34sm+22st+22t;鲤属于鲤科、鲤亚科、鲤属,染色体数目为2n=100,核型为22m+34sm+22st+22t。已有研究表明,红鲫(♀)×鲤(♂)杂交第一代(F₁)和第二代(F₂)为二倍体,F₂能产生染色体数不减数的配子,在第三代(F₃)中形成四倍体鱼。通对F₁和F₃进行胚胎染色体制片,在染色体水平上探讨红鲫和鲤远缘杂交的多倍体发生途径及F₂产生不减数配子的潜能。结果表明,F₁混合胚胎都为二倍性胚胎,没有发现单倍性和多倍性胚胎,但F₃混合胚胎中则有染色体数为100,150,200甚至300的染色体分裂相,推测F₂生殖细胞发生了一次或多次染色体数加倍,产生了二倍性和更高倍性的配子,它们结合形成了不同倍性的F₃胚胎。实验证明双亲基因组大小及核型相似的鲫鲤远缘杂交第一代不发生多倍化,但获得的二倍体杂交后代能产生不减数配子,在F₃中产生多倍体鱼。     

Effect of Dietary Supplementation with Hydrolyzed Wheat Gluten on Growth Performance,Cell Immunity and Serum Biochemical Indices of Weaned Piglets （Sus scrofa）

To investigate the effects of dietary supplementation with hydrolyzed wheat gluten (HWG) on growth performance, cell immunity and serum biochemical indices of weaned piglets, 160 crossed (Large White×Landrace) and weaned piglets were randomly divided into 4 treatments with 4 replicates of 10 piglets each. The piglets in each treatment were fed an experimental diet containing either 0 g kg-1 HWG (control group), 30 g kg-1 HWG (3% HWG group), 50 g kg-1 HWG (5% HWG group), or 2.5 g kg-1 glycyl-L-glutamine (0.25% Gly-Gln group). The results showed that the diarrhea rates in 3% HWG and 5% HWG groups were significantly lower than in control group from d 1 to 14 (P＜0.05), while the average daily gain (ADG) in each of two groups was increased (P＞0.05). When compared with control group, dietary supplementation with 3% HWG increased the ratio of CD4+:CD8+ and the ratio of serum albumin and globulin concentrations (A:G) on d 14 and 28, as well as the proliferation of T- and B-lymphocytes (P＞0.05) on d 28. In addition, on d 14 and 28, the A:G ratio in 5% HWG group was significantly higher than in control group (P＜0.05), while the ratio of CD4+:CD8+ increased slightly (P＞0.05). Interestingly, 0.25% Gly-Gln group had higher proportion of CD3+ (P＞0.05) and CD4+ (P＜0.05) on d 14 than control group, but growth performances of 0.25% Gly-Gln group were negatively affected at all experiment stages. These results suggested that HWG might improve the growth performance of piglets by strengthening cell immunity and decreasing the occurrence of diarrhea during the prophase after weaning.     

草酸处理对桂七芒果冷害及细胞壁代谢的影响

为探讨草酸处理对低温冷藏下芒果冷害及细胞壁代谢的影响,本试验以桂七芒果果实为试材,采用5 mmol·L^-1草酸溶液浸泡处理,以清水浸泡处理为对照,并于4℃贮藏,分析芒果的冷害指数、丙二醛(MDA)含量、相对电导率、硬度、细胞壁物质含量、细胞壁代谢酶的变化。结果表明,与对照组相比,草酸处理显著降低了低温贮藏14 d后桂七芒果果实冷害指数、MDA含量、相对电导率、原果胶和纤维素含量,显著降低了低温贮藏28 d后果实的硬度;显著提高了低温贮藏14 d后果实水溶性果胶含量及多聚半乳糖醛酸酶(PG)、果胶甲酯酶(PME)、纤维素酶(Cx)活性,显著提高了贮藏21 d后果实β-半乳糖苷酶(β-Gal)活性。综上所述,草酸处理能减轻桂七芒果冷害,维持采后果实细胞壁降解酶较高活性和水溶性果胶含量。本研究为揭示草酸减轻芒果果实冷害机制提供了依据,可为草酸应用于其他冷敏型果实的贮藏保鲜提供理论参考。     

微生物燃料电池在环境监测中的研究进展

微生物燃料电池在环境监测领域有巨大的应用潜力.概述微生物燃料电池应用于环境监测的基本原理,对目前已有的微生物燃料电池型传感器为监测方法进行详细的介绍,包括微生物燃料电池用于易降解碳源、有毒污染物及微生物数量检测三方面的研究.最后探讨了微生物燃料电池传感器目前还未被广泛应用于实际水质监测的原因,以期为未来研究开发高性能微生物燃料电池传感器提供理论参考依据.     

山羊可溶型干细胞因子mRNA在不同毛色皮肤组织中的表达水平简

为探讨可溶性干细胞因子（stem cell factor, SCF）基因表达水平与山羊毛色间的相关性，本试验利用实时荧光定量PCR（QRT-PCR）技术研究了SCF基因mRNA在黑色和白色山羊皮肤中的表达量，并对结果进行统计分析。经内参基因校正后，黑色山羊皮肤中可溶型SCF的相对表达量是白色山羊相对表达量的0.27倍（P>0.05）。可溶型SCF mRNA表达量可能与山羊毛色表型不存在相关性。     

降钙素基因相关肽对猪小肠上皮细胞钠离子依赖型Ⅱb磷转运蛋白表达及磷吸收的影响

本试验旨在研究不同浓度降钙素基因相关肽(CGRP)对猪小肠上皮细胞钠离子依赖型Ⅱb磷转运蛋白(NaPi-Ⅱb)表达和磷吸收的影响.选用第3～8代猪小肠上皮细胞进行试验,按单因素试验设计,将试验细胞分为1个对照组和5个CGRP(1×10-11～1×10-7 mmol/L)试验组,每组设6个重复.用4-甲基偶氮唑盐(MTT)法测定细胞生长速度,采用比色法测定CGRP干预24 h后细胞上清液磷含量,用RT-PCR法检测NaPi-Ⅱb mRNA相对表达量,以及蛋白质印迹(Western blot)法检测NaPi-Ⅱb蛋白表达.结果表明:与对照组相比,不同浓度CGRP对细胞生长没有显著影响(P＞0.05);各试验组均极显著或显著地促进了磷的吸收和NaPi-ⅡbmRNA的相对表达量(P＜0.01或P＜0.05);除1×10-10 mmol/L组外均显著提高了NaPi-Ⅱb蛋白的表达(P＜0.05).研究结果表明,CGRP通过诱导小肠上皮细胞中NaPi-Ⅱb的表达促进细胞磷的吸收,其中以1×10-9、1×10-8 mmol/L浓度的CGRP促进效果较为显著.     

原花青素A-1体内外对猪与小鼠T淋巴细胞亚群的影响

为研究从碎米花杜鹃叶中分离得到的化合物原花青素A-1（Proanthocyanidin A-1，简称PAA-1）的免疫增强活性，初步从细胞水平上探讨其免疫增强机制。体外试验采用流式细胞术，检测PAA-1体外对小鼠脾淋巴细胞T细胞亚群CD4和CD8单阳性和双阳性T淋巴细胞亚群百分率及CD4+/CD8+比值；体内试验通过饲喂不同剂量的PAA-1后，检测试验猪外周血淋巴细胞CD4和CD8单阳性以及CD4+/CD8+比值。结果证明，体外试验中同阴性对照组相比，PAA-1能单独或协同Con A提升具CD4+、CD8+及CD4+CD8+表型的T淋巴细胞亚群百分率，提高CD4+/CD8+的比值；体内试验中饲喂中、高剂量的PAA-1的试验猪外周血中具有CD4+、CD8+表型的T淋巴细胞的百分率及CD4+/CD8+的比值均有显著提高。说明PAA-1可通过增加辅助性T淋巴细胞和细胞毒性T淋巴细胞数量、促进T淋巴细胞的成熟以及增加CD4+/CD8+的比值发挥增强细胞免疫的作用，为其进一步开发为新型免疫增强剂提供试验依据。     

黑龙江地区鲤疱疹病毒3型的流行病学调查及其主要囊膜蛋白的抗原表位预测

2015-2016年对来自黑龙江地区46个养殖场送检的鲤鱼进行锦鲤疱疹病毒(Koi herpes virus,KHV)的分离鉴定,并应用DNAStar等软件对检出的阳性样本的主要囊膜蛋白(Major envelop protein,MEP)基因进行生物信息学分析。结果显示,KHV的检出率约为6.5%,3株阳性样本具有相同的MEP基因序列,称之为KHV-HLJ1516。MEP基因开放阅读框为771 bp,编码256个氨基酸,相对分子质量为28 280.58,等电点为8.40。对KHV-HLJ1516的MEP基因序列同源性分析表明,其与KHV-GZ11分离株仅有1个碱基不同,但并未导致氨基酸发生改变,碱基相似性为99%;而与HZ419分离株相比,KHV-HLJ1516的MEP基因有3个碱基发生突变,相应的氨基酸由Asn变为IIe。聚类分析结果显示,KHV-HLJ1516与KHV-GZ11处于同一分支,而HZ419位于另一分支。B细胞抗原表位预测结果显示,KHV-HLJ1516的MEP的抗原表位主要位于4~11,24~40,42~63,82~110,209~218,238~249氨基酸区段。     

Antioxidant and anti‐inflammatory activities of Pinus radiata bark extract in salmonid cell lines

A fish meal supply shortage is limiting aquaculture development. Currently, plant‐based proteins, such as soya bean meal, are being used as an alternative protein source, despite that such a diet can adversely affect fish, such as by inducing an inflammatory response. A possible solution is to include dietary additives in farm diets to counteract negative effects. One such solution originates from pine bark extracts, which present bioactive properties. In this study, the antioxidant and anti‐inflammatory properties of Pinus radiata bark extracts were evaluated for the first time in a salmonid cell line. This extract chemically demonstrated antioxidant activity through 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH = 58.4 ± 1.1%) and ferric ion reducing antioxidant power (FRAP = 575 ± 17 mgEqFe(II)·g extract^?1) assays. Additionally, the extract showed high flavonoid and phenolic compound contents. Up to 100 mg mL^?1, the P. radiata extract showed no cytotoxicity in the CHSE‐214 salmonid embryo cell line. Moreover, the antioxidant activity of the extract (50 μg mL^?1) was evaluated by a dichlorofluorescein (DCFH) assay in the SHK‐1 salmon cell line challenged with an oxidant stimulus (H₂O₂), showing 58.9% activity. The extract also protected DNA from oxidative damage, as observed through a comet assay. When assessing anti‐inflammatory properties in an in vitro inflammation model, the extract significantly reduced the relative expression of the pro‐inflammatory cytokines interleukin‐1β (IL‐1β), tumour necrosis factor‐α (TNF‐α) and interleukin‐8 (IL‐8) and of the inducible cyclooxygenase‐2 (COX‐2) enzyme. These results suggest a potential application of P. radiata bark extract in functional foods in aquaculture.     

大白菜游离小孢子培养技术高效体系的研究

以大白菜吉红82、#534DH 群体及#438 群体为试材，研究了利用细胞破碎仪机械提取小孢子与人工挤压提取小孢子对大白菜游离小孢子活力及提取量的影响。结果表明：机械提取替代人工挤压可在短时间内同时提取多份样品，并可快速调整小孢子的培养浓度。收集40 个适期花蕾于5 mL 离心管内，3 000 r·min-1 破碎10 s，将提取的小孢子定容于25 mL NLN-13 培养基，可确保小孢子浓度在适宜培养范围内，并成功诱导胚胎发生。