蛇毒类凝血酶鼠单克隆抗体的制备

采用杂交瘤技术,获得了４株稳定分泌抗蛇毒类凝血酶的单克隆抗体杂交瘤细胞株,均属ＩｇＧ１ｋ链,４株杂交瘤细胞培养上清液效价为 ４ × １０－１～４ × １０－２,腹水效价为 ４ × １０－１～３．２ ×１０－５。     

维甲酸诱导的脊柱裂小鼠的脊髓全基因组表达谱分析(英文)

关于维甲酸胚胎病理学的研究很多,维甲酸受体在器官发生、发育及神经管闭合过程中发挥重要作用。但维甲酸影响这些过程的机制还不清楚。在本研究中,我们发现,小鼠怀孕8天时,给予母体连续3次维甲酸灌胃,将导致胎儿脊柱裂,发生率为96.77%。本研究应用微阵列技术,在维甲酸诱导的脊柱裂小鼠胎儿的脊髓组织中发现了134个差异表达在1.5倍以上的基因。基因富集分析显示,母亲暴露于维甲酸导致的胎儿脊柱裂,与促凋亡和抗凋亡、细胞增殖、迁徙、细胞骨架成分以及细胞或局部粘附等基因功能簇相关,提示这些细胞成分和生物学的功能缺陷促使脊柱发育异常。我们的研究提供了脊柱裂的全基因组基因表达模式,有助于理解神经管缺陷的病因和病理学。     

水杉愈伤组织诱导及植株再生

通过愈伤组织诱导器官发生途径,建立了水杉（Metasequoia glyptostroboides）的植株再生体系,探讨了不同外植体（种胚、幼叶切块、茎段、根段）和植物生长调节剂对不定芽直接再生和愈伤组织诱导器官发生的影响。结果表明：以种胚、无菌苗叶片、茎段和根作为外植体,在MS补加2,4-D、NAA和6-BA不同组合的培养基上都能诱导得到愈伤组织,其中种胚诱导愈伤组织效果最好,诱导率可达100%,茎诱导效果次之,诱导率为97.1%。诱导愈伤组织效果较好的培养基有：MS＋1.0mg·L-12,4-D＋0.5mg·L-16-BA、MS＋0.1mg·L-16-BA＋1.0mg·L-1NAA、MS＋0.5mg·L-16-BA＋1.0mg·L-1NAA、MS＋1.0mg·L-16-BA＋1.0mg·L-1NAA、MS＋0.5mg·L-16-BA＋2.0mg·L-1NAA、MS＋1.0mg·L-16-BA＋2.0mg·L-1NAA和MS＋0.5mg·L-12,4-D＋0.5mg·L-1NAA。以愈伤组织在MS培养基上植株再生效果最好,再生率为62.5%。     

Systematic Evaluation of Protein Sequence Filtering Algorithms for Proteoform Identification Using Top‐Down Mass Spectrometry

Complex proteoforms contain various primary structural alterations resulting from variations in genes, RNA, and proteins. Top‐down mass spectrometry is commonly used for analyzing complex proteoforms because it provides whole sequence information of the proteoforms. Proteoform identification by top‐down mass spectral database search is a challenging computational problem because the types and/or locations of some alterations in target proteoforms are in general unknown. Although spectral alignment and mass graph alignment algorithms have been proposed for identifying proteoforms with unknown alterations, they are extremely slow to align millions of spectra against tens of thousands of protein sequences in high throughput proteome level analyses. Many software tools in this area combine efficient protein sequence filtering algorithms and spectral alignment algorithms to speed up database search. As a result, the performance of these tools heavily relies on the sensitivity and efficiency of their filtering algorithms. Here, we propose two efficient approximate spectrum‐based filtering algorithms for proteoform identification. We evaluated the performances of the proposed algorithms and four existing ones on simulated and real top‐down mass spectrometry data sets. Experiments showed that the proposed algorithms outperformed the existing ones for complex proteoform identification. In addition, combining the proposed filtering algorithms and mass graph alignment algorithms identified many proteoforms missed by ProSightPC in proteome‐level proteoform analyses.     

单核细胞增多性李斯特菌氨基肽酶Lmo1711体外表达及其酶活分析

对单核细胞增多性李斯特菌(简称单增李斯特菌)lmo1711基因编码的氨基肽酶进行克隆表达与纯化,并研究该重组蛋白的体外酶学特性。首先通过生物信息学分析预测Lmo1711与氨基肽酶家族成员的亲缘关系及关键活性位点的保守性。利用SWISS-MODEL模拟预测该蛋白的空间结构;构建Lmo1711原核表达载体并转化入E.coli Rosetta中,诱导表达重组目的蛋白,并利用镍离子亲和层析方法纯化目的蛋白;以氨基酸-对硝基苯胺偶联物为底物,Lmo1711通过水解底物N端氨基酸残基产生游离对硝基苯胺单体,405 nm处检测吸光值对该产物进行检测从而分析Lmo1711的酶学特性。在此基础上系统研究Lmo1711对不同氨基酸残基底物的催化特异性,及不同金属离子对该酶活性的影响。经原核表达纯化获得49.3 kDa的重组Lmo1711蛋白,与预测分子量一致;生物信息学分析推测Lmo1711属于M29氨基肽酶家族,且存在保守关键氨基酸活性位点(Glu250、Glu316、His345、Tyr352、His378、Asp380);酶活分析显示,Lmo1711具有较强的氨基肽酶活性,针对不同底物的结合和催化能力差异较大,对亮氨酸残基的亲和程度最高;Lmo1711氨基肽酶活性具有金属离子依赖性,Co~(2+)、Cd~(2+)、Zn~(2+)等多种金属离子均能显著增强其活性,其中Co~(2+)的激活效应最显著。本试验首次发现并证实,单增李斯特菌Lmo1711属于M29氨基肽酶家族成员,具有较强的催化活性,且对金属离子具有不同程度的依赖性。     

Long non‐coding RNA highly up‐regulated in liver cancer promotes epithelial‐to‐mesenchymal transition process in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is an oral and maxillofacial malignancy that exhibits high incidence worldwide. In diverse human cancers, the long non‐coding RNA (lncRNA) highly up‐regulated in liver cancer (HULC) is aberrantly expressed, but how HULC affects OSCC development and progression has remained mostly unknown. We report that HULC was abnormally up‐regulated in oral cancer tissues and OSCC cell lines, and that suppression of HULC expression in OSCC cells not only inhibited the proliferation, drug tolerance, migration and invasion of the cancer cells, but also increased their apoptosis rate. Notably, in a mouse xenograft model, HULC depletion reduced tumorigenicity and inhibited the epithelial‐to‐mesenchymal transition process. Collectively, our findings reveal a crucial role of the lncRNA HULC in regulating oral cancer carcinogenesis and tumour progression, and thus suggest that HULC could serve as a novel therapeutic target for OSCC.     

通过和玉米杂交诱导硬粒小麦单倍体

硬粒小麦（Ｔｒｉｔｉｃｕｍ ｄｕｒｕｍ Ｄｅｓｆ．）ＤＲ１４７授以超甜玉米（Ｚｅａ ｍ ａｙｓ Ｌ．） ｓｓ ７７００的花粉后,在８３．４％ 的柱头上观察到花粉萌发及花粉管长入胚囊,有９．９％ 的子房发生了卵细胞的单受精,１．９％ 的子房发生了中央细胞的单受精,３２．７％ 的子房发生了双受精。尽管双受精后可同时形成胚和胚乳,但胚乳往往发育迟缓,甚至败育。硬粒小麦×玉米形成的杂合子核型高度不稳定,在最初的几次细胞分裂中,来自父本玉米的染色体逐步被排除,最后形成硬粒小麦单倍体胚。在授以玉米花粉４ ｈ 后用１００ ｐｐｍ ２,４－Ｄ溶液浸蘸硬粒小麦穗部,可以有效地促进幼胚在缺乏胚乳或胚乳败育情况下的生长和发育。授粉９—１３ ｄ 后由５３３个硬粒小麦子房解剖出２５个胚,得胚率为４．７％ 。通过幼胚拯救获得１１棵正常植株,植株获得率为２．１％ 。根尖细胞染色体计数表明,它们为单倍体（２ｎ＝ ２ｘ＝ １４）。