象草幼穗离体培养植株再生研究

以象草幼穗为外植体材料、改良的MS为基本培养基,研究了不同外源激素组合对不同发育时期幼穗愈伤组织诱导和植株再生能力的影响.结果表明,象草幼穗离体培养最适长度为2～5 cm;愈伤组织诱导培养基中添加4.0 mg/L 2,4-D 0.05 mg/L KT和4.0 mg/L 2,4-D 0.10 mg/L KT时,颗粒状愈伤组织诱导率分别为79.0%和72.6%;转入添加3.0 mg/L 2,4-D 0.2 mg/L 6-BA的继代培养基,分别有40.9%和74.0%的愈伤组织保持颗粒状结构;在添加2.0 mg/L CPPU 0.01 mg/L NAA和0.50 mg/L KT 0.5 mg/L IAA的分化培养基上,经过继代培养后的颗粒状愈伤组织的成苗率分别为36.4%和38.5%,总成苗率达50.2%和43.9%.3片叶大小的幼苗转入附加NAA 0.50 mg/L的1/2 MS壮根培养基,试管苗移栽成活率达95%以上.在继代培养过程中逐代选择外表呈白色、干燥、紧密、颗粒状的愈伤组织,是提高其植株再生能力的有效方法.     

The influence of temperature and age on the T1 relaxation time of the equine distal limb

The extent of fat suppression using short tau inversion recovery (STIR) imaging is variable between horses. Our aim was to determine if patient's age and/or hoof temperature have an influence on the T(1) relaxation time of bone marrow in the equine distal limb, thereby affecting the suppression of fat signal. Magnetic resonance imaging was conducted on standing horses and cadaver samples using a low-field magnet (0.27 T). The hoof temperature was measured at the lateral side of the coronary band. A modified inversion recovery fast spin-echo (IR-FSE) sequence was used to measure the signal intensity for a range of inversion times (TIs) at six different regions of interest (ROI): (1) distal aspect of the proximal phalanx, (2) proximal aspect of the middle phalanx, (3) distal aspect of the middle phalanx, (4) navicular bone, (5) proximal aspect of the distal phalanx, and (6) distal aspect of the distal phalanx. The T(1) of the bone marrow in the equine distal limb was calculated from the results and was found to increase by 3.13 ± 0.08 (SE) ms/°C. There was no significant effect of age (2-16 years) but the T(1) values measured from the limbs of young (< 1 year) animals were considerably longer (32.6 ± 1.7 (SE) ms). Similar effects of temperature and age were found for all measured ROIs but there were significant differences in the mean values of T(1) , ranging from +7.7 (distal aspect of the distal phalanx) to -13.2 ms (distal aspect of the proximal phalanx).     

鸡X期胚盘细胞电转染外源基因条件的探索

以EGFP为报告基因体外电穿孔转染鸡X期胚盘细胞,探讨适宜电转染条件以及影响鸡ES细胞存活率和转染率因素。分离鸡X期胚盘细胞进行培养、传代及鉴定,二代细胞设定不同的电压、脉冲时间、质粒浓度、细胞密度及孵育温度等条件转染。电击后10 min,0.4%台盼蓝染色,血细胞计数板计数,计算存活率。48 h后在荧光显微镜下计绿色荧光细胞数和总细胞数,计算转染率。结果表明:电转染鸡ES细胞的最优化电压为280 v,脉冲时间为75μs,质粒浓度为20μg/mL,转染前4℃、转染后25℃(室温)或4℃各静置10 min,细胞密度调整在1×105个/mL×106个/mL,尽量使细胞处于对数生长期。电穿孔法转染鸡ES细胞是简便有效的方法,利用优化条件转染ES细胞,可以满足进一步实验的要求。     

口蹄疫病毒VP1基因的原核可溶性表达

针对重组原核表达载体表达目的蛋白以包涵体形式存在的问题,作者对影响外源蛋白表达的IPTG的浓度、温度、时间等因素均进行了探索,以观察VP1蛋白的可溶性情况。通过PCR技术将VP1基因克隆至pGEM-T载体中,然后将pET-28a(+)和pGEM-T载体分别进行双酶切,构建重组的pET-28a-VP1载体,将重组载体转化至BL21中,诱导后经SDS-PAGE检测可见约29 ku的目的蛋白条带。插入的外源目的蛋白主要以包涵体的形式存在,上清中的可溶性蛋白甚微。试验结果表明,这可能与蛋白本身的氨基酸组成有重要关联。     

PRDM16——控制BAT和WAT发育的分子开关

棕色脂肪组织通过大量表达解偶联蛋白-1(UCP-1)以加强线粒体呼吸作用的解偶联,使能量以热量形式散失,从而抵御肥胖和相关疾病.研究发现,PRDM16是调节棕色脂肪细胞形成的关键转录因子,是控制棕色和白色脂肪细胞特异基因表达程序的分子开关,其机制是C末端结合蛋白和过氧化物酶体增殖剂活性受体γ辅助激活子1 (PPARγ-coactivator-1α and β,PGC-1α/β) 竞争性结合PRDM16,分别形成PRDM16/CtBPs和PRDM16/PGC-1s转录复合物,前者可激活棕色脂肪特异基因的表达,后者则抑制白色脂肪特异基因的表达.论文通过对PRDM16的结构、功能及其作用机制的介绍,有助于研究者了解棕色脂肪组织发育的调控系统,为肥胖和相关疾病的治疗提供新思路.     

草原红牛CAPN1基因第5外显子多态性与肉质性状的相关研究

本研究以草原红牛为研究对象,对CAPN1基因的第5外显子进行SNP分析,发现第5外显子存在A3717G突变,同时与肉质性状进行相关分析发现其与pH及嫩度相关。这将为系统的研究草原红牛以及其他肉牛品种的肉质特性提供分子生物学依据。     

Bactrian camel (Camelus bactrianus) integrins αvβ3 and αvβ6 as FMDV receptors: Molecular cloning, sequence analysis and comparison with other species

Integrins are heterodimeric adhesion receptors that participate in a variety of cell–cell and cell–extracellular matrix protein interactions. Many integrins recognize RGD sequences displayed on extracellular matrix proteins and the exposed loops of viral capsid proteins. Four members of the αv integrin family of cellular receptors, αvβ3, αvβ6, αvβ1 and αvβ8, have been identified as receptors for foot-and-mouth disease virus (FMDV) in vitro, and integrins are believed to be the receptors used to target epithelial cells in the infected animals. To analyse the roles of the αv integrins from a susceptible species as viral receptors, we have cloned Bactrian camel αv, β3 and β6 integrin cDNAs and compared them to those of other species. The coding sequences for Bactrian camel integrin αv, β3 and β6 were found to be 3165, 2289 and 2367 nucleotides in length, encoding 1054, 762 and 788 amino acids, respectively. The Bactrian camel αv, β3 and β6 subunits share many structural features with homologues of other species, including the ligand binding domain and cysteine-rich region. Phylogenetic trees and similarity analyses showed the close relationships of integrin genes from Bactrian camels, pigs and cattle, which are each susceptible to FMDV infection, that were distinct from the orders Rodentia, Primates, Perissodactyla, Carnivora, Galliformes and Xenopus. We postulate that host tropism of FMDV may in part be related to the divergence in integrin subunits among different species.     

2种三叶草杂种F1代胚性愈伤组织筛选

以高加索三叶草(Trifolium ambiguum Bieb.)与白三叶(Trifolium.repens L.)杂交后胚离体培养产生的F₁无菌苗的茎段为外植体,筛选诱导愈伤组织的最适培养基,将F₁茎段产生的愈伤组织经过继代后转移到分化培养基中,研究不同浓度激素组合对体细胞胚胎产生的影响。结果表明:MS+6-BA+NAA是诱导F₁茎段愈伤组织的适宜培养基;MS+2,4-D+6-BA+NAA+KT+CH为F₁茎段愈伤组织的适宜分化培养基;对分化后的胚性愈伤进行组织学观察,可见其表面形成许多瘤状突起,即胚性细胞团,它们可以继续发育形成体细胞胚,为快速得到数量较多的杂种F₁再生苗奠定基础。     

福建省羊传染性脓疱病毒F1L、B2L和VIR基因的遗传变异分析

为探明2014年-2015年在福建省流行的羊传染性脓疱病毒(ORFV)遗传变异情况,对10株ORFV流行毒株的F1L、B2L和VIR基因进行克隆、测序及分析。结果表明,10株ORFV F1L基因之间的核苷酸序列同源性为97.6%~100%,与国内株的核苷酸序列同源性为96.8%~99.7%,与NZ2参考株的核苷酸序列同源性为96.3%~97.1%;同NZ2参考株比较,FJ-YT2014缺失2个氨基酸;10株ORFV B2L基因之间核苷酸序列同源性为97.5%~99.9%,与国内株的核苷酸序列同源性为96.7%~99.5%,与NZ2参考株的核苷酸序列同源性为96.7%~97.7%;10株ORFV VIR基因之间的核苷酸序列同源性为95.8%~99.5%,与国内株的核苷酸序列同源性为94.6%~99.6%,与NZ2参考株的核苷酸序列同源性为94.6%~96.4%。基于基因核苷酸序列的遗传进化分析表明,10株ORFV F1L基因与福建省分离株、山西株和新疆株亲缘关系较近;10株ORFV B2L基因与新疆、山西、德国毒株亲缘关系较近;10株ORFV VIR基因与台湾、新疆株亲缘关系较近。结果提示,当前福建省流行的ORFV F1L、B2L和VIR基因尚未出现明显变异,但是其F1L、B2L和VIR基因核苷酸序列之间普遍存在异质性。     

植物内整流K~+通道AKT1的研究进展

K~+是植物生长发育所必需的大量营养元素。内整流K~+通道(Arabidopsis K~+transporter 1,AKT1)属于Shaker家族,是介导K~+吸收的重要通道,为质膜的K~+感应器,参与调节细胞的生长发育、调控气孔运动及植物蒸腾作用,能够提高植株的抗旱耐盐性,因而在植物生长过程中具有重要作用。该文概述了AKT1的结构、组织表达定位和表达调控及功能等方面的研究进展,并提出采用蛋白组学、基因工程技术及RNAi手段深入研究K~+、Na~+吸收及转运的协同调控机制,提高作物对土壤中K~+的利用效率及AKT1在植物生理代谢、抗逆性中的作用。