赤霉素和细胞分裂素调控苹果果实早期生长发育机理的研究

采用流式细胞术（ＦＣＭ）及酶联免疫法（ＥＬＩＳＡ）从细胞学和激素生理学的角度研究了ＧＡ４／７、ＢＡ及ＣＰＰＵ调节苹果果实早期发育的可能机理。ＧＡ４／７（５０ｍｇ／Ｌ）抑制了苹果果肉细胞分裂，未提高果实内源细胞分裂素（ＺＲｓ，ｉＰＡ）含量推测它主要通过促进工而促进果实生长，ＢＡ（５０ｍｇ／Ｌ）和ＣＰＰＵ（１２．５ｍｇ／Ｌ）可以显著促进苹果幼果的细胞分裂，ＣＰＰＵ的细胞分裂素活性较ＢＡ高，ＢＡ和ＣＰＰ     

氯虫苯甲酰胺和氟虫腈对黏虫细胞色素P450基因表达的影响

为筛选出黏虫Mythimna separata参与杀虫剂解毒代谢的主效细胞色素P450基因,采用叶片浸渍法测定了用于处理黏虫3龄幼虫的亚致死浓度,通过构建转录组测序文库并结合数字基因表达(digital gene expression,DGE)对不同处理的黏虫进行测序,并运用实时荧光定量PCR(realtime quantitative polymerase chain reaction,RT-qPCR)技术验证12个P450基因的表达情况。结果表明,用于处理黏虫的氯虫苯甲酰胺和氟虫腈亚致死浓度LC_(10)分别为0.15、13.66 mg/L;对照样品、氟虫腈处理样品和氯虫苯甲酰胺处理样品分别获得59 521 504、64 838 148和41 722 990个原始序列数据,分别获得57 441 216、62 368 912和40 285 164个过滤后的序列数据;过滤后的序列长度分别为8.62、9.36和6.04 G;碱基错误率均为0.02%;Phred数值大于20、30的碱基占总碱基的百分比均高于90.59%;鸟嘌呤+胞嘧啶(guanine cytosine,GC)含量分别为47.16%、48.94%和47.55%,表明转录组测序质量较高;黏虫受氯虫苯甲酰胺胁迫后,29个P450基因表达量上调,27个P450基因表达量下调;黏虫受氟虫腈胁迫后,23个P450基因表达量上调,26个P450基因表达量下调;12个P450基因表达量的RT-qPCR技术检测结果与DGE测序文库显示的结果基本一致。     

Changes in selected stress and immune‐related genes in Atlantic cod,Gadus morhua,following overcrowding

Using Atlantic cod, Gadus morhua, as a model for the stress response in gadoid fish, the changes in the expression of some stress and immune genes as well as the profiles of plasma cortisol were examined. Adult fish were kept at a density of ca. 100 kg m^?3 by lowering the water level in the rearing tank for 1 h and this short‐term crowding stress was repeated thrice over a 12‐h interval period. Blood samples were collected before exposure and at 2, 24 and 72 h post crowding. Plasma cortisol level significantly increased at 2 h post crowding but returned to pre‐crowding levels 24 h after exposure. The relative expression of the stress response genes, glucose transporter‐3 and a putative heat shock protein 70 significantly increased at 2 and 24 h post crowding respectively. Significant up‐regulation of the pro‐inflammatory cytokines, interleukin (IL)‐1β and IL‐8, as well as anti‐bacterial genes, g‐type lysozyme and bactericidal permeability‐increasing protein/lipopolysaccharide‐binding protein (BPI/LBP) was also observed at 2 h and the levels were maintained until 72 h post exposure, except for BPI/LBP which had maximum up‐regulation at 24 h. The present observations have implications with respect to fish welfare and assessment of the health status of the farmed fish.     

水稻Pi基因分子标记的物理图谱锚定

整理国际注册或期刊报道的已定位Pi基因,并在物理图谱上锚定,为抗稻瘟病基因-Pi基因的精细定位、图位克隆提供研究基础.利用www.gramene.org网站公布的Pi基因的分子标记,在测序图谱Gramene Annotated Nip-ponbare Sequence 2006上进行物理图谱锚定.通过本研究把已定位的89个Pi基因的42个锚定到其物理图谱的28个位点上.这42个Pi基因,除了已克隆的11个基因外,其余的均可作为Pi克隆基因的候选基因作进一步的研究.     

甜玉米品质遗传改良研究进展

甜玉米为具有果蔬和谷物特征的新型农作物，其营养丰富，适口性好，受到国内外消费者和科研人员的广泛关注。甜玉米含淀粉合成缺陷基因，糖类在胚乳中大量积累，是鲜食玉米主要类型之一。根据缺陷基因的不同，甜玉米可分为普甜玉米、超甜玉米和加强甜玉米等类型，不同类型间食味品质和营养品质差异较大。甜度、爽脆度、果皮厚度、风味等是甜玉米的主要食用品质特性，这些性状受微效多基因控制，其遗传研究及育种改良应用均面临很大挑战。目前，甜玉米品质相关的研究取得了一定进展，研究者对甜玉米食味品质（含糖量、果皮厚度等）和营养品质（维生素、矿物元素、蛋白含量等）的主要评价指标进行鉴定和分析，获得了大量研究成果，主要集中在表型变异、遗传力、QTL 位点、候选基因等层面。这些研究的开展为甜玉米营养改良提供了重要的理论和分子基础。对甜玉米品质相关（包括甜玉米形成的遗传基础、维生素 E、果皮厚度、锌含量、玉米黄质和蛋白质含量）的国内外研究进展进行综述，并探讨了甜玉米遗传改良的发展方向，为甜玉米品质改良和优质品种培育提供理论依据。     

螺旋环剥对‘糯米糍’荔枝坐果与碳水化合物及激素的影响

研究结果表明，幼‘糯米滋’荔枝主要螺旋环剥能减少碳水化合物向根系转运，从而增加叶片和果实中的碳水化合物含量，增多果实中赤霉素类物质和降低脱落酸类物质含量。坐果率的提高与赤霉素／脱落酸的比值较高关系密切。     

莱航鸡rDNA重复基因家族的克隆

动物rDNA基因是一种GC含量较高、结构复杂的重复序列。通过结合生物信息学技术,经反复摸索后选用LAPCR法扩增莱航鸡rDNA基因重复序列,经测序鉴定最终克隆了莱航鸡的3个rDNA基因及其2个间隔序列。研究对克隆复杂DNA序列时引物设计的特别规则、反应体系的改进、DNA聚合酶的选用、循环参数的调整等进行了探索。     

The Correlation Between Polymorphisms of Exon1 and Exon4 of DRB1 Gene and Brucellosis in Kazakh Sheep

The purpose of this experiment was to study the correlation between exon 1 and 4 polymorphisms of DRB1 gene and brucellosis in Kazakh sheep.Using RBPT serological tests to try sheep serum,reference in GenBank sheep MHC Class Ⅱ area DRB1 gene sequences (Accession No.:NC_040271.1),the exon 1 and 4 pieces designed primers,using PCR-SSCP and DNA sequencing technology to 230 Kazak sheep DRB1 gene polymorphism detection,analyze its polymorphism loci and the relationship between the Kazak sheep Brucella susceptibility.The results showed that 66 Kazakh sheep were positive for Brucella in RBPT test,and the positive detection rate was 28.7%.There was one SNP locus (F1-G22A) in exon 1 fragment,and sequencing determined two genotypes (GG and GA),the dominant allele and genotype were G and GG respectively,and the susceptibility genotype of the polymorphisms of F1-G22A was GA.Chi-square test showed that there was no significant correlation between the polymorphisms of DRB1 gene F1-G22A and Brucella susceptibility in Kazakh sheep (P>0.05).According to the analysis of bioinformatics online software,the F1-G22A polymorphic sites lead to the change of RNA secondary structure and the decrease of minimum free energy,and lead to the change of protein secondary structure.No SNPs were found in DRB1 exon 4 fragment.Therefore,there might be a certain correlation between the polymorphisms of DRB1 gene F1-G22A and Brucella susceptibility in Kazakh sheep.     

Cloning, characterization and expression of cDNA containing major histocompatibility complex class I, IIα and IIβ genes of Japanese flounder Paralichthys olivaceus

ABSTRACT:   The nucleotide sequences of Japanese flounder Paralichthys olivaceus , major histocompatibility complex (MHC) cDNA, classical MHC class Iα, non-classical MHC class Iβ, MHC class IIα and IIβ, were determined. The domain structures and antigen binding motifs of vertebrate MHC are conserved in the Japanese flounder MHC. A phylogenetic analysis supports the classification of these genes into class I and class II MHC. Classical MHC class Iα was ubiquitously expressed, whereas the non-classical MHC class Iβ was expressed mainly in lymphoid organs, gills, intestine and stomach. The MHC classes IIα and IIβ were also ubiquitously expressed.