草鱼3个6-磷酸葡萄糖酶催化亚基的基因表达分析及高糖饲料对其表达的影响

为了探讨6-磷酸葡萄糖酶催化亚基(glucose-6-phosphatase catalytic subunit,G6PC)在草鱼(Ctenopharyngodon idellus)糖代谢中的作用,采用同源序列比对的方式,在草鱼基因组中获取了3个g6pc基因的序列,通过序列比对和进化树分析,将其分别命名为g6pca、g6pcb1和g6pcb2,其编码的氨基酸序列与斑马鱼(Danio rerio)、虹鳟(Oncorhynchus mykiss)和人(Homo sapiens)具有较高的同源性,相似度分别为85%～94%、64%～83%和54%～66%。同线性分析表明g6pc在草鱼染色体上的分布与斑马鱼等高度相似,表明草鱼g6pc基因在进化中具有较高的保守性。利用RT-PCR检测3个基因在鳃、脂肪、脑、心脏、肝、肾、前肠、中肠、后肠和肌肉10个组织中的表达,结果显示, g6pca在脑和肝中表达量较高,脂肪组织次之; g6pcb1在肝中表达量最高,中肠次之; g6pcb2在心脏表达量最高,其次为脂肪组织。同时探讨了高糖饲料对草鱼不同g6pc亚型转录水平的影响,以及不同浓度葡萄糖和胰岛素刺激草鱼肝细胞(L8824)后对g6pca转录水平的影响。结果显示,饲喂高糖饲料(7周)后,与对照组相比,草鱼肝脏g6pca mRNA水平显著升高, g6pcb1和g6pcb2 mRNA水平无显著变化。离体情况,与5 mmol/L葡萄糖组相比,15 mmol/L葡萄糖显著增加了L8824的g6pca mRNA水平,且1 mol/L胰岛素可以抑制这种作用; 30 mmol/L葡萄糖对L8824 g6pca mRNA水平无显著性影响。本研究表明,草鱼g6pc发生加倍后存在功能分化,高糖可以诱导g6pca mRNA的表达,而对g6pcb1和g6pcb2的转录水平无影响,其具体功能还需进一步研究。     

Comparative analysis of genetic effects of wheat‐Dasypyrum villosum translocations T6V#2S·6AL and T6V#4S·6DL

Wheat‐Dasypyrum villosum translocations T6V#2S·6AL and T6V#4S·6DL, carriers of Pm21 and PmV, respectively, confer high resistance to wheat powdery mildew. For better understanding of the difference in genetic effect between them, a RIL population was constructed based on the cross between “Yangmai 18” carrying T6V#2S·6AL and “Yangmai 22” carrying T6V#4S·6DL. Analysis of distribution of the translocations showed that T6V#2S·6AL is much more transmittable than T6V#4S·6DL. By comparing their effects on main agronomic traits, we firstly found that T6V#2S·6AL contributes greatly to top spikelet fecundity, but causes a decrease of 6.7%–10.5% of spike number. No stable effects of T6V#4S·6DL on agronomic traits were found, except for positive effect on plant height. Excitingly, a new recombinant, T6V#4S‐6V#2S·6AL carrying PmV, was screened and proved to have a higher transmission rate than the original translocation T6V#4S·6DL, which will greatly promote the utilization of PmV. The above conclusions of this research will provide important guidance for utilization of Pm21 and PmV more effectively, in wheat powdery mildew resistance breeding.     

Role of TLR4-TRPC6 in LPS-induced NF-κB P65 expression and nuclear translocation in airway epithelial 16HBE cells

AIM: To investigate the role of Toll-like receptor 4 (TLR4) and transient receptor potential channel 6 (TRPC6) signaling pathway in lipopolysaccharide (LPS)-induced nuclear factor-κB (NF-κB) P65 expression and nuclear translocation in airway epithelial cells (16HBE) for supplementing the mechanism for airway inflammation. METHODS: After stimulating the 16HBE cells with LPS at 1 mg/L for 0, 0.5, 2, 6, 12 and 24 h, the expression of NF-κB P65 at mRNA and protein levels in the 16HBE cells were determined by RT-PCR and Western blot respectively, and the nuclear translocation of NF-κB P65 was detected by immunocytochemical staining method. The effects of TLR4 inhibitor CLI-095 at 5 μmol/L and TRPC6 agonist Hyp9 at 10 μmol/L on LPS (1 mg/L)-induced NF-κB P65 expression and nuclear translocation in the 16HBE cells were determined by RT-PCR, Western blot and immunocytochemical staining. RESULTS: LPS increased the mRNA and protein expression of NF-κB P65 and nuclear translocation in the 16HBE cells(P<0.05). TLR4 inhibitor CLI-095 reduced the mRNA and protein expression of NF-κB P65 and nuclear translocation induced by LPS, while Hyp9 enhanced the mRNA and protein expression of NF-κB P65 and nuclear translocation induced by LPS in the 16HBE cells(P<0.05). CONCLUSION: LPS induces the expression and nuclear translocation of NF-κB P65 in the 16HBE cells via TLR4-TRPC6 signaling pathway.     

Molecular cloning and functional characterization of the fatty acid delta 6 desaturase (FAD6) gene in the sea cucumber Apostichopus japonicus

The sea cucumber (Apostichopus japonicus), an important echinodermata, had high value in nutrition and medicine for its rich collagen, sulphated polysaccharide, glycosides and polyunsaturated fatty acids (PUFA). The cDNA of the fatty acid desaturase gene in A. japonicus (AJFAD6) was cloned and was found to encode a desaturase with delta 6 FAD activity. Sequence analysis indicated that AJFAD6 included an open reading frame of 1392 bp, encoding 463 amino acids. AJFAD6 has all the conserved motifs found in other members of the FAD6 family, including an N‐terminal cytochrome b5 domain and three histidine‐rich regions. qRT‐PCR showed that AJFAD6 was expressed in all tissues tested during juvenile development and was mainly expressed in the respiratory tree at 150 days after adherence (150 days) and in the intestine at 100 days. Furthermore, AJFAD6 mRNA was also detected in the analysed adult tissues, with higher expression in the intestine and testis. Functional characterization of AJFAD6 in a recombinant yeast, Pichia pastoris, showed that AJFAD6 could catalyse exogenous linoleic acid (LA) and α‐linolenic acid (ALA) to produce γ‐linoleic acid (GLA) and stearidonic acid (STA), respectively, at conversion rates of 11.1% for LA to GLA and 3.4% for ALA to STA. Our results suggested that the biosynthetic pathway of PUFA existed in the sea cucumber, but endogenous production of eicosapentaenoic acid, arachidonic acid and docosahexaenoic acid from either LA or ALA precursor appeared to be limited.     

Significant improvement of shrimp growth performance by growth hormone‐releasing peptide‐6 immersion treatments

Growth hormone‐releasing peptide‐6 (GHRP‐6) is one of the earliest developed synthetic peptidyl growth hormone secretagogue receptor agonists. These compounds mimic the effect of the endogenous ligand ghrelin. In vertebrates, ghrelin is a potent circulating orexigenic hormone with functional roles in controlling food intake, energy expenditure, adiposity, growth hormone secretion and immunity. Ghrelin has been studied mainly in vertebrates; thus, little is known about its role in invertebrates, including crustaceans. We first evaluated the effect of GHRP‐6 injection over feed intake in shrimp and its effects on shrimp growth when the peptide was administrated by successive immersion baths. GHRP‐6 increased feed intake, body weight and size, the number of rostral spines and gill branches, protein concentration and haemocyte number in treated shrimps. We also evaluated the peptide uptake and clearance in a pharmacokinetics, using [H³]GHRP‐6 administered to postlarvae. Given a limited exposure and efficient clearance of the peptide‐associated radioactivity from larvae, our findings suggested that GHRP‐6‐treated Litopenaeus vannamei can be consumed safely by humans after aquaculture applications. These results propose that GHRP‐6 could be an additional tool to study growth physiology in crustaceans and also a promising candidate for development into a new biotechnology product for improving shrimp growth and quality.     

Association of TNF-α, IL-10 and IL-6 promoter polymorphisms in pulmonary tuberculosis patients and their household contacts of younger age group

Single nucleotide polymorphisms (SNPs) of cytokine genes have been found to be involved in the clinical outcome of Tuberculosis. The present study was aimed to identify the high risk genotypes in Tuberculosis patients and their household contacts. A total of 490 subjects were studied which includes 150 active pulmonary tuberculosis patients (APTB), 190 household contacts (HHC) and 150 healthy controls (HC). The SNPs of TNF-α (-308A/G), IL-10(-1082G/A) and IL-6(-174G/C) were performed by ARMs PCR. The IL-10 GA genotype showed significant association in APTB and HHC and was 2.3 times higher risk in APTB and 3.7 times in HHC compared to HCs. The A allele was found to be significantly associated with the risk of disease. The CC genotype of IL-6 was found to be significantly associated in APTB and an insignificant positive association in HHCs. The multifactor dimensionality reduction (MDR) analysis indicated that the genotypes of IL-6 were showing high risk with GA genotype of IL-10. In conclusion the gene interaction may be useful for identification of genotypes as biomarkers to distinguish high risk individuals.     

铬胁迫对黄豆生理特性的FTIR研究和铬积累特征

为了对Cr~(6+)污染土壤修复提供参考依据。通过水培,研究了不同Cr~(6+)水平对黄豆幼苗根、茎、叶的傅立叶红外光谱(FTIR)图谱变化,同时测定Cr~(6+)的亚细胞分布和Cr~(6+)富集的影响。结果表明:幼苗对Cr~(6+)的积累能力与处理浓度呈正比。其叶片富集的Cr~(6+)在细胞壁分布最多(37.14%~63.52%),线粒体和叶绿体最少(12%)。根组织在1064、1404、1635、2924、3417 cm-1等处峰高呈先升后降的变化趋势,可能是在低Cr~(6+)浓度,通过增加糖类和氨基酸等有机物含量来响应Cr~(6+)胁迫;茎组织在1072、1427、1643、2924、3387 cm-1等处峰高呈现不显著变化趋势;叶组织在1110、1396、1651、2924、3433 cm-1等处峰高先降后升,表明叶中一些富含O-H小分子有机物质(碳水化合物)被运输到根部螯合Cr~(6+)来响应低Cr~(6+)胁迫。研究结果表明,黄豆幼苗能有效地吸收土壤中的Cr~(6+),在Cr~(6+)污染土壤植物修复技术领域,拥有潜在的利用价值。     

不同浓度NAA/6BA配比对不同品种甘薯茎尖培养特性的影响

为明确不同品种甘薯茎尖培养的最佳NAA/6BA配比,设置0.1 mg/L/2.5 mg/L、0.2 mg/L/2.5 mg/L、0.2 mg/L/1.0 mg/L 3组NAA/6BA浓度配比处理,观测不同浓度激素处理对‘北京553’、‘红香蕉’、‘苏薯8号’、‘烟薯25’、‘安吉芋’、‘济徐23’、‘渝紫7号’、‘商薯19’茎尖培养成苗率、愈伤组织直径、不定根数目、叶片数和植株高度的影响,同时调查不同品种试管苗的移栽成活率。结果表明,‘红香蕉’、‘济徐23’、‘渝紫7号’、‘商薯19’在0.1 mg/L/2.5 mg/L的处理下培养效率最高;‘安吉芋’在0.2 mg/L/2.5 mg/L的处理下培养效率最高;‘苏薯8号’、‘北京553’、‘烟薯25’在0.2 mg/L/1.0 mg/L的处理下培养效率最高。因此,在甘薯茎尖培养过程中,不同甘薯品种适宜的NAA/6BA配比存在显著差异,在实际生产中应根据品种特性来进行调整激素的用量和比例。     

生化抑制剂组合与施肥模式对黄泥田稻季氨挥发的影响

为探讨生化抑制剂组合与施肥模式对黄泥田稻季氨挥发的影响,采用二因素随机区组设计,研究生化抑制剂组合[N-丁基硫代磷酰三胺(NBPT)、N-丙基硫代磷酰三胺(NPPT)和2-氯-6-(三氯甲基)吡啶(CP)]与施肥模式(一次性和分次施肥)互作对黄泥田稻季氨(NH3)挥发动态变化的影响。结果表明:黄泥田稻季NH3挥发损失主要集中于施肥后1周,峰值发生在第1~3 d。生化抑制剂组合与施肥模式对黄泥田稻季NH3挥发损失量的效应显著。尿素分次施用处理稻季NH3挥发净损失率较一次性施用处理显著降低24.6%。不同施肥模式下,硝化抑制剂CP处理显著提高田面水NH+4-N峰值和NH3挥发速率峰值,增加稻田NH3挥发损失量;脲酶抑制剂NBPT/NPPT或配施CP处理明显延缓尿素水解,降低NH3挥发速率峰值,减少稻田NH3挥发损失量。新型脲酶抑制剂NPPT单独施用及与CP配施的稻田NH3挥发动态变化与NBPT相似。相关性分析表明,稻田NH3挥发速率与田面水NH+4-N浓度和pH值呈显著正相关,而与气温、土温和土壤相对湿度无显著相关性。总之,生化抑制剂组合与适宜的运筹相结合更能有效减少黄泥田稻季NH3挥发损失。     

小麦骨干亲本繁6产量相关性状关键基因组区段的遗传效应

繁6是中国小麦育种最重要的骨干亲本之一,明确其优良特性的遗传机制对小麦育种具有重要意义。本研究鉴定了39个繁6衍生品种的7个产量相关性状,并利用全基因组SSR标记分析了繁6中控制这些性状重要遗传区段和基因位点在子代中的遗传效应。表型鉴定结果表明,繁6产量相关性状在不同世代衍生品种中表现无显著差异,表明这些性状在衍生品种选育过程中受到选择并稳定遗传。利用已获得的控制小麦产量相关"一致性"QTL区段的417个SSR标记进行分子扫描,发现11个繁6特异SSR标记在其衍生后代中被高频率遗传。性状–标记关联分析表明,21个来自繁6的特异SSR标记与产量相关性状极显著关联(P0.01)。同时鉴定出分别位于2A和5A染色体的Xgdm93.3–Xgwm526.2和Xbarc100–Xgwm156.1区段,前者控制株高和小穗数,后者控制千粒重。本研究证实,上述两个与小麦产量相关性状关联的位点或区段在小麦产量育种进程中受到强烈的人为定向连续选择,并在四川乃至西南麦区小麦产量育种中发挥了重要作用。