Gateway技术构建交链孢菌JH505 cDNA文库

Gateway(R)技术构建Cdna文库,利用λ噬菌体的位点特异性重组,避免使用限制性内酶切割Cdna,能够解决常规方法构建Cdna文库的技术缺陷.首次应用Gateway(R)技术构建交链孢菌Cdna文库,经检测Cdna入门文库的滴度达到1×107cfu/Ml,文库总容量为9×107cfu,平均插入片段为1510bp.通过LR重组把入门文库转换为表达文库,表达文库的滴度为1.58×106cfu/Ml,文库总容量为6.32×106cfu,平均插入片段大小为1680bp.表达文库的构建为进一步克隆植物激活蛋白基因打下了基础.     

荧光素标记JH12.6探针进行的人DNA指纹图分析

采用荧光素标记和鲁米诺化学发光技术,建立了ＤＮＡ指纹图的分析方法。用该方法标记ＪＨ１２．６探针获得了清晰易读、分辨率高的人ＤＮＡ指纹图。经对云南省７８名无关个体进行ＤＮＡ指纹图分析,计算出无关个体的相关机率为７．４×１０（－１１）,平均等位基因频率为０．０９。比较同位素（３２）Ｐ标记方法表明,用荧光素标记ＪＨ１２．６探针进行人ＤＮＡ指纹图分析,具有简便、快速、安全、经济的特点,可在法医学鉴定及其它领域里推广应用。     

Gateway○R技术构建交链孢菌JH505 cDNA文库

GatewayD○R技术构建cDNA文库,利用λ噬菌体的位点特异性重组,避免使用限制性内酶切割cDNA,能够解决常规方法构建cDNA文库的技术缺陷。首次应用GatewayD○R技术构建交链孢菌cDNA文库,经检测cDNA入门文库的滴度达到1×10.7cfu/mL,文库总容量为9×10.7cfu,平均插入片段为1510bp。通过LR重组把入门文库转换为表达文库,表达文库的滴度为1.58×10.6cfu／mL,文库总容量为6.32×10.6cfu,平均插入片段大小为1680bp。表达文库的构建为进一步克隆植物激活蛋白基因打下了基础。     

原位PCR技术研究鼻咽癌组织中bcl-2／JH融合基因

为研究bcl-2／JH融合基因与鼻咽癌发生的关系,应用兰套式原位PCR技术对41例石蜡包埋鼻咽癌组织中bcl-2/JH融合基因进行检测。结果发现41例癌组织中bcl-2／JH融合基因阳性6例,阳性率为14.6%,bcl-2基因的两个热点断裂区mbr和mcr与免疫球蛋白重链JH形成的融合基因mbr-JH和mcr-JH各占50％。bcl-2／JH融合基因形成与癌组织学分级和转移间无明显关系（P＞0.05）。本表明bcl-2/JH融合基因与鼻咽癌发生可能有一定关系,其中mbr-JH和mcr-JH同为bcl-2基因在鼻咽癌的两个重要基因异常改变形式。     

Gateway(R)技术构建交链孢菌JH505 cDNA文库

Gateway○R技术构建cDNA文库,利用λ噬菌体的位点特异性重组,避免使用限制性内酶切割cDNA,能够解决常规方法构建cDNA文库的技术缺陷。首次应用Gateway○R技术构建交链孢菌cDNA文库,经检测cDNA入门文库的滴度达到1×107cfumL,文库总容量为9×107cfu,平均插入片段为1510bp。通过LR重组把入门文库转换为表达文库,表达文库的滴度为1.58×106cfu/mL,文库总容量为6.32×106cfu,平均插入片段大小为1680bp。表达文库的构建为进一步克隆植物激活蛋白基因打下了基础。     

干酪乳杆菌JH23代谢产物对单胺氧化酶的抑制作用

本文旨在分离干酪乳杆菌JH-23中具有抑制单胺氧化酶(MAO)活性的代谢产物.用乙酸乙酯对干酪乳杆菌JH23发酵液进行抽提,得到的脂溶性成分和水溶性成分在一定浓度范围内对MAO的抑制活性呈较好的量效关系.其中,脂溶性成分对MAO-A、MAO-B抑制作用的IC50分别为1.97和5.67 mg/mL;水溶性成分对MAO-A、MAO-B抑制作用的IC50分别为1.59和4.83 mg/mL.抑制特征曲线显示,两者对MAO-A与MAO-B的抑制作用均呈竞争性抑制.从水溶性成分中分离得到的活性组分W1对MAO-A、MAO-B抑制作用的IC50分别为0.33和1.13 mg/mL.通过进一步分离,以及红外和质谱分析,确定了组分W1中具有较强MAO抑制作用的物质为琥珀酸.     

Nutritional regulation of JH synthesis: a mechanism to control reproductive maturation in mosquitoes?

Juvenile hormone (JH) titers must be modulated to permit the normal progress of development and reproduction in mosquitoes. In adult female Aedes aegypti, JH levels are low at adult eclosion, elevated in sugar-fed females and low again after a blood meal. Although degradation plays a role, JH titer is fundamentally determined by the rate of biosynthesis in the corpora allata gland (CA). CA from newly eclosed females (0-1 h after emergence) exhibit a very low basal JH biosynthetic activity, Aedes-allatotropin stimulates the CA in newly emerged females to produce JH. There is a correlation between nutritional reserves at adult emergence (teneral reserves) and CA activity. JH synthesis is significantly reduced in teneral females that emerge with low nutritional reserves. Taking a blood meal results in a reduction of CA activity. The biosynthetic activity of Ae. aegypti CA is significantly inhibited by factors present in the head, as well as by Anopheles gambiae PISCF-allatostatin. Nutritional signals affect the release of allatotropin and allatostatins by the brain resulting in the activation or inhibition of JH synthesis. JH is therefore an important part of a transduction mechanism that connects changes in the nutritional status with activation of specific physiological events during reproduction.     

Characterization of a highly polymorphic region 5′ to JH in the human immunoglobulin heavy chain

A cloned DNA segment 1.25 kilobases (kb) upstream from the joining segments of the human heavy chain immunoglobulin gene revealed extensive polymorphic variation at this locus, and the polymorphic pattern was stably transmitted to the next generation. Genomic restriction analysis showed that the polymorphism was caused by insertions/deletions within an MspI/BamHI fragment. Sequencing of one allele, 848 base pairs (bp) long, revealed eleven 50-base-pair tandem repeats. A second allele, 648 bp long, was cloned from a human genomic cosmid library, sequenced, and found to contain four fewer repeats than the first allele. A survey of 186 chromosomes from unrelated individuals of primarily northern European descent revealed at least six alleles.     

牛胚系基因中两种 JH 和 Cμ抗体基因的克隆与分析

根据NCBI GenBankTM中登录的2个牛抗体重链可变区J基因(JH)(序列号为AY158087,AY149283)的序列不同之处设计PCR引物,能从同一个体的Holstein牛基因组DNA中扩增得到与以上2个基因分别相同的序列,证明这2个JH基因的差异不是由于牛个体或品种不同引起的.提取牛脾脏总RNA,RT-PCR扩增IgM cDNA,测序结果显示:序列号为AY149283的JH基因中第六外显子JH6是一个功能基因,它可以编码牛IgM的部分CDR3区和完整的FR4区,从2种IgM cDNA克隆的测序结果可以看出,其恒定区序列分别与序列号为U63637和AY230207的2种抗体重链恒定区μ基因(Cμ)cDNA序列相同.PCR扩增JH-Cμ序列,测序结果表明:序列号为AY158087的JH基因是同以上2种Cμ基因分别串连在一起的(序列号分别为AY230207和U63637).以上结果证明:序列号为U63637和AY230207的2个Cμ基因分别与AY149283的JH基因串联在一起,都能够参与牛IgM的产生,它们与AY158087的JH基因共同存在于同一个体Holstein牛胚系基因中.     

乳酸片球菌L-乳酸脱氢酶基因的克隆及在重组大肠杆菌JH12中的过量表达

以工程菌Escherichia coli SZ85基因组为模板,克隆得到乳酸片球菌(Pediococcus acidilactici)的L-乳酸脱氢酶基因(ldhL),连接到pUcm-T载体后,双酶切然后将其连接到表达载体pET-28a上,重组质粒经筛选后转入染色体上含有ldhL基因(来源P.acidilactici)的工程菌Escherichia coli JH12。P.acidilactici的ldhL基因过量表达体系E.coli JH12(pET-28a-ldhL)能利用浓度7%的木糖为碳源进行厌氧发酵,过量表达ldhL使L-乳酸产量提高了10 g/L,达64.86 g/L,糖酸转化率高达96%。     

棉株内含物和外源JH对棉蚜成蚜有翅率及种群消长的影响

通过系统研究得出 ,棉花植株中油酸、缬氨酸和脯氨酸对棉蚜种群消长有影响 ,油酸、天门冬氨酸和丝氨酸对棉蚜成蚜有翅率有影响 ;外源保幼激素类似物对棉蚜种群消长和成蚜有翅率均有重要影响 .