Human extracellular superoxide dismutase (EC-SOD) expression in transgenic chicken

Extracellular superoxide dismutase (EC-SOD) is a metalloprotein and functions as an antioxidant enzyme. In this study, we used lentiviral vectors to generate transgenic chickens that express the human EC-SOD gene. The recombinant lentiviruses were injected into the subgerminal cavity of freshly laid eggs. Subsequently, the embryos were incubated to hatch using phases II and III of the surrogate shell ex vivo culture system. Of 158 injected embryos, 16 chicks (G0) hatched and were screened for the hEC-SOD by PCR. Only 1 chick was identified as a transgenic bird containing the transgene in its germline. This founder (G0) bird was mated with wild-type hens to produce transgenic progeny, and 2 transgenic chicks (G1) were produced. In the generated transgenic hens (G2), the hEC-SOD protein was expressed in the egg white and showed antioxidant activity. These results highlight the potential of the chicken for production of biologically active proteins in egg white. [BMB Reports 2013; 46(8): 404-409]     

过表达秋茄C2H2型锌指蛋白基因KcZFP提高烟草耐盐性

基因转录调节是植物对非生物胁迫适应机制的一个重要方面,转录调节因子在胁迫信号转导途径中调节下游基因的表达,在建立植物对胁迫适应性过程中起到重要作用.锌指蛋白是功能多样的转录调节因子蛋白家族,家族成员在植物响应非生物胁迫方面扮演着重要角色.本研究以秋茄C2H2型锌指蛋白编码基因KcZFP为目的基因,在烟草中过表达KcZFP,分析C2H2型锌指蛋白在植物耐盐性中的作用.研究结果显示:转基因株系中,KcZFP表达量显著提高.过表达KcZFP的烟草植株的耐盐性明显提高,在200 mmol/L NaCl处理的条件下,KcZFP过表达烟草中脯氨酸水平远高于野生型植株.对光合作用参数比较分析显示,在KcZFP过表达植株中净光合速率受盐胁迫的影响小于野生型植株,光合系统在一定程度上得到了保护.研究结果说明KcZFP作为转录调节因子参与了植物的渗透调节,对植物的耐盐性具有贡献.     

A soluble form of human nectin-2 impairs exocrine secretion of pancreas and formation of zymogen granules in transgenic mice

Transgenic mouse lines expressing a soluble form of human nectin-2 (hNectin-2Ig Tg) exhibited distinctive elevation of amylase and lipase levels in the sera. In this study, we aimed to clarify the histopathology and to propose the transgenic mouse lines as new animal model for characteristic pancreatic exocrine defects. The significant increase of amylase and lipase levels in sera of the transgenic lines approximately peaked at 8 weeks old and thereafter, plateaued or gradually decreased. The histopathology in transgenic acinar cells was characterized by intracytoplasmic accumulation of abnormal proteins with decrease of normal zymogen granules. The hNectin-2Ig expression was observed in the cytoplasm of pancreatic acinar cells, which was consistent with zymogen granules. However, signals of hNectin-2Ig were very weak in the transgenic acinar cells with the abnormal cytoplasmic accumulaion. The PCNA-positive cells increased in the transgenic pancreas, which suggested the affected acinar cells were regenerated. Acinar cells of hNectin-2Ig Tg had markedly small number of zymogen granules with remarkable dilation of the endoplasmic reticulum (ER) lumen containing abundant abnormal proteins. In conclusion, hNectin-2Ig Tg is proposed as a new animal model for characteristic pancreatic exocrine defects, which are due to the ER stress induced by expression of mutated cell adhesion molecule that is a soluble form of human nectin-2.     

Hoverflies (Diptera: Syrphidae) benefit from a cultivation of the bioenergy crop Silphium perfoliatum L. (Asteraceae) depending on larval feeding type,landscape composition and crop management

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Joint‐linkage mapping and GWAS reveal extensive genetic loci that regulate male inflorescence size in maize

Both insufficient and excessive male inflorescence size leads to a reduction in maize yield. Knowledge of the genetic architecture of male inflorescence is essential to achieve the optimum inflorescence size for maize breeding. In this study, we used approximately eight thousand inbreds, including both linkage populations and association populations, to dissect the genetic architecture of male inflorescence. The linkage populations include 25 families developed in the U.S. and 11 families developed in China. Each family contains approximately 200 recombinant inbred lines (RILs). The association populations include approximately 1000 diverse lines from the U.S. and China. All inbreds were genotyped by either sequencing or microarray. Inflorescence size was measured as the tassel primary branch number (TBN) and tassel length (TL). A total of 125 quantitative trait loci (QTLs) were identified (63 for TBN, 62 for TL) through linkage analyses. In addition, 965 quantitative trait nucleotides (QTNs) were identified through genomewide study (GWAS) at a bootstrap posterior probability (BPP) above a 5% threshold. These QTLs/QTNs include 24 known genes that were cloned using mutants, for example Ramosa3 (ra3), Thick tassel dwarf1 (td1), tasselseed2 (ts2), liguleless2 (lg2), ramosa1 (ra1), barren stalk1 (ba1), branch silkless1 (bd1) and tasselseed6 (ts6). The newly identified genes encode a zinc transporter (e.g. GRMZM5G838098 and GRMZM2G047762), the adapt in terminal region protein (e.g. GRMZM5G885628), O‐methyl‐transferase (e.g. GRMZM2G147491), helix‐loop‐helix (HLH) DNA‐binding proteins (e.g. GRMZM2G414252 and GRMZM2G042895) and an SBP‐box protein (e.g. GRMZM2G058588). These results provide extensive genetic information to dissect the genetic architecture of inflorescence size for the improvement of maize yield.     

EMS对三个玉米自交系的诱变效应分析

EMS诱变玉米花粉是玉米化学诱变的主要技术。该研究以生产上3个常用的玉米自交系K305、21-ES、R08为材料,对其花粉用不同浓度的EMS诱变处理,探讨其EMS诱变的最佳浓度范围,明确其诱变效应。结果表明：3个自交系经过不同浓度的EMS诱变后,其结实率随着浓度的增大表现出减小的趋势,从其半致死剂量来看,EMS诱变花粉的适宜浓度范围自交系K305和R08均为0.67~1.0 mL?L-1,21-ES在1.67 mL?L-1附近。 M1代不同性状其变异幅度和变异系数与对照相比主要表现出增大的趋势,其不同性状的生物学效应在材料间表现不一致,表明性状在不同材料间对EMS的敏感性不一样,生育期表现为21-ES>K305>R08;主要株型性状表现为R08>21-ES>K305;主要雄穗性状K305和21-ES比R08敏感;主要果穗性状表现为21-ES>K305>R08。 M2代整体表现为变异谱扩大,其株高、穗位高和叶面积以及主要果穗性状的变异表现复杂,主要雄穗性状中除K305的M2株系雄穗分枝数呈双向变异外,其余M2株系整体偏向于雄穗变短,雄穗分枝数减小。该研究结果为后续研究和应用打下了基础。     

太空诱变玉米核不育突变体矮化的遗传及外施赤霉素分析

为了解太空诱变玉米核不育突变体矮化的遗传规律和原因,该研究以不育突变体为母本,自交系178、478为父本,对测交 F1、F2群体进行育性鉴定和株高分析,对 F2可育株进行基因型和株高分析,对姊妹交后代分离群体进行育性鉴定和株高、雄穗长度、节间数、节间长度分析,同时,还对姊妹交后代分离群体进行施赤霉素处理,调查育性和株高的变化。结果表明：178和478背景下的 F1表现出与测交母本一样的极显著差异;在178和478核背景下的 F2中,不育株株高极显著矮于可育株,两核背景下的不育株间株高差异不显著,而可育株间株高差异极显著;F2中纯合和杂合可育株的株高差异不显著;姊妹交后代分离群体中不育株株高、雄穗长度、节间数和节间长度极显著小于可育株;外施赤霉素的不育株在苗期表现出对赤霉素一定的敏感性,但株高最终未恢复正常高度。因此,得出该突变体矮化表现稳定,与不育性状并存,且不受细胞核背景的影响;核不育基因对植株株高的矮化无剂量效应;突变体的矮化与雄穗长度、节间数和节间长度有关;突变体不完全属于赤霉素不敏感型,其矮化并不是单一缺乏赤霉素而引起。该研究结果为认识太空诱变玉米核不育突变体矮化的遗传和生理机制提供了参考。     

人源抗体制备及临床应用研究进展

与常规治疗药物相比,抗体药物具有靶向性强、特异性好等优点,其作为一类重要的治疗性药物,近年来在临床中的应用逐渐增多,为疾病的治疗提供了新的选择,应用范围逐渐从肿瘤、自身免疫性疾病及慢性炎症扩展到心血管和感染性等疾病中。人源抗体的全部结构是由人类抗体基因所编码的,因此避免了异种蛋白长期应用引起的不良反应,加之人源抗体制备技术的不断发展完善,使其逐渐成为治疗性抗体研发的首要选择。综述了近年来治疗性人源抗体的主要制备技术及其在临床中应用的最新进展,同时探讨了人源抗体制备技术的不足之处,以期为人源抗体的发展提供借鉴和思路。