Inhibition of poly(ADP-ribose) polymerase activity by Bcl-2 in association with the ribosomal protein S3a.

We screened a human lymphocyte cDNA library using the yeast two-hybrid system and an automodification domain of PARP as a probe. The DNA sequence of an isolated clone (clone 3-9) was identical to the partial cDNA sequence of the human ribosomal protein S3a. We confirmed that PARP interacts with clone 3-9 by performing binding studies using a GST-3-9 fusion protein as bait. We also demonstrated that native S3a in nuclear extracts of HL-60 cells interacts with the automodification domain of PARP and that PARP from nuclear extracts is coprecipitated with the GST-3-9 fusion protein. Furthermore, we demonstrated that Bcl-2 interacts with PARP in association with S3a and that the interaction of S3a and Bcl-2 with PARP causes a significant decrease in PARP activity. Since Bcl-2 failed to inhibit PARP activity in the absence of S3a, we suggest that Bcl-2 together with S3a prevents apoptosis probably by inhibiting PARP activity.     

Mouse-rabbit germinal vesicle transfer reveals that factors regulating oocyte meiotic progression are not species-specific in mammals

A series of experiments were designed to evaluate the meiotic competence of mouse oocyte germinal vesicle (GV) in rabbit ooplasm. In experiment 1, an isolated mouse GV was transferred into rabbit GV-stage cytoplast by electrofusion. It was shown that 71.8% and 63.3% of the reconstructed oocytes completed the first meiosis as indicated by the first polar body (PB1) emission when cultured in M199 and M199 + PMSG, respectively. Chromosomal analysis showed that 75% of matured oocytes contained the normal 20 mouse chromosomes. When mouse spermatozoa were microinjected into the cytoplasm of oocytes matured in M199 + PMSG and M199, as many as 59.4% and 48% finished the second meiosis as revealed by the second polar body (PB2) emission and a few fertilized eggs developed to the eight-cell stage. In experiment 2, a mouse GV was transferred into rabbit MII-stage cytoplast. Only 13.0-14.3% of the reconstructed oocytes underwent germinal vesicle breakdown (GVBD) and none proceeded past the MI stage. When two mouse GVs were transferred into an enucleated rabbit oocyte, only 8.7% went through GVBD. In experiment 3, a whole zona-free mouse GV oocyte was fused with a rabbit MII cytoplast. The GVBD rates were increased to 51.2% and 49.4% when cultured in M199 + PMSG and M199, respectively, but none reached the MII stage. In experiment 4, a mouse GV was transferred into a partial cytoplasm-removed rabbit MII oocyte in which the second meiotic apparatus was still present. GVBD occurred in nearly all the reconstructed oocytes when one or two GVs were transferred and two or three metaphase plates were observed in ooplasm after culturing in M199 + PMSG for 8 hr. These data suggest that cytoplasmic factors regulating the progression of the first and the second meioses are not species-specific in mammalian oocytes and that these factors are located in the meiotic apparatus and/or its surrounding cytoplasm at MII stage.     

猴免疫缺陷病毒特异性免疫复合物沉着与猴AIDS多系统病变关系的探讨

目的观察猴免疫缺陷病毒(SIV)感染后,病毒特异性免疫复合物(IC)在不同时间、不同组织的沉着情况,初步研究其与AIDS多系统病变的联系。方法对8只不同时间感染SIV的恒河猴及1只未感染SIV的猴进行尸检以获取多系统组织标本,进行连续切片和IgG、C3、SIV p27免疫荧光染色,并对结果进行比较分析。结果IgG、C3、p27在多个猴、多种组织的相同位置出现相同模式的荧光表达,证明存在IC的沉着;其中脑血管周(8/8),心肌间微血管(6/8)、和淋巴结副皮质(6/8)及生发中心(5/8)是阳性率最高的部位,肾小球及肾间质、肠黏膜固有层也有较多IC的沉着,且在感染中、晚期IC出现的比例更高。结论SIV感染后出现广泛的SIV-IC沉积,且随病情的进展而加重;IC可能是SIV导致AIDS多系统病变的主要形式。针对此过程进行研究,可帮助了解AIDS并发多系统器官病变的机制及研究新的治疗方法。     

Apelin-13 induces ERK1/2 but not p38 MAPK activation through coupling of the human apelin receptor to the Gi2 pathway

Apelin signaling to the family of mitogen-activated protein kinases (MAPKs), such as extracellular-regulated kinases 1/2 (ERK1/2) and p38 MAPK, through the coupling of apelin receptor (APJ) to G-protein, mediates important pathophysiological responses. Although apelin fragments have been reported to induce ERK1/2 activation through G_i-protein, the intracellular pathways by which APJ activates these MAPKs are only partially understood. Here, using stably transfected human embryonic kidney 293 (HEK293) cells overexpressing human APJ (HEK293-apelinR), we showed that apelin-13 signaling leads to ERK1/2 and p38 MAPK pathways through APJ activation. It was found in HEK293-apelinR cells that ERK1/2 activation was initiated by apelin-13 at 5 min, with the peak of activation occurring at 15 min, and a return to the basal level within 60 min. The activation of ERK1/2 appeared to be dose-dependent with a significant activation being observed at 10 nM apelin-13 and maximal activation at 100 nM. However, phosphorylated-p38 MAPK was not detected in HEK293-apelinR cells treated with apelin-13. We also shown that the apelin-13-induced ERK1/2 activation requires a coupling with pertussis toxin-sensitive G-protein, and that overexpression of dominant-negative G_i2 completely inhibits the apelin-13-induced ERK1/2 activation. In addition, treatment with apelin-13 resulted in a concentration-dependent reduction of forskolin-stimulated cAMP production. It is therefore suggested that apelin-13 activates ERK1/2 but not p38 MAPK, which involves the coupling of APJ to the G_i2 cascade. In conclusion, the ERK1/ 2, but not p38 MAPKpathway is activated by apelin-13 through coupling of human APJ to G_i2-protein, which contributes to cellular responses.     

High-resolution mapping reveals linkage between genes in common bean cultivar Ouro Negro conferring resistance to the rust,anthracnose, and angular leaf spot diseases

Key message

Co-segregation analysis and high-throughput genotyping using SNP, SSR, and KASP markers demonstrated genetic linkage between Ur-14 and Co-3 ⁴ /Phg-3 loci conferring resistance to the rust, anthracnose and angular leaf spot diseases of common bean.

Abstract

Rust, anthracnose, and angular leaf spot are major diseases of common bean in the Americas and Africa. The cultivar Ouro Negro has the Ur-14 gene that confers broad spectrum resistance to rust and the gene cluster Co-3 ⁴ /Phg-3 containing two tightly linked genes conferring resistance to anthracnose and angular leaf spot, respectively. We used co-segregation analysis and high-throughput genotyping of 179 F_2:3 families from the Rudá (susceptible) × Ouro Negro (resistant) cross-phenotyped separately with races of the rust and anthracnose pathogens. The results confirmed that Ur-14 and Co-3 ⁴ /Phg-3 cluster in Ouro Negro conferred resistance to rust and anthracnose, respectively, and that Ur-14 and the Co-3 ⁴ /Phg-3 cluster were closely linked. Genotyping the F_2:3 families, first with 5398 SNPs on the Illumina BeadChip BARCBEAN6K_3 and with 15 SSR, and eight KASP markers, specifically designed for the candidate region containing Ur-14 and Co-3 ⁴ /Phg-3, permitted the creation of a high-resolution genetic linkage map which revealed that Ur-14 was positioned at 2.2 cM from Co-3 ⁴ /Phg-3 on the short arm of chromosome Pv04 of the common bean genome. Five flanking SSR markers were tightly linked at 0.1 and 0.2 cM from Ur-14, and two flanking KASP markers were tightly linked at 0.1 and 0.3 cM from Co-3 ⁴ /Phg-3. Many other SSR, SNP, and KASP markers were also linked to these genes. These markers will be useful for the development of common bean cultivars combining the important Ur-14 and Co-3 ⁴ /Phg-3 genes conferring resistance to three of the most destructive diseases of common bean.

     

Study on fibroin heavy chain of the silkwormBombyx mori by fluorescencein situ hybridization (FISH)

The sericulture industry plays a very important role in our national economy. Silkworm (Bombyx mori) is always regarded as a model animal and biological reactor. There have been detailed studies on the structure, expression and control and molecular evolution of silk genes. However, few, if any, reports are available on the localization of structural genes in silkworm by molecular cytogenetics. The present experiment has tentatively localized theFib-H gene at the distal end of the 25th linkage group, namely at the 25-0.0 position, and verified thatFib-H has only one locus, thus providing a temporary solution to the problem about its localization.     

东亚中更新世古人类下颔第二臼齿釉质-齿质连接面三维形状和釉质厚度分布

东亚中更新世古人类在头骨、下颌骨、牙齿等解剖部位表现出不同程度的形态多样性,中期成员代表为直立人,而晚期成员的演化地位具有较大争议。为进一步了解东亚中更新世古人类内部的形态变异特点和为东亚中更新世晚期古人类分类提供依据,本文使用微分同胚的表面匹配（Diffeomorphic Surface Matching, DSM）和形态测量图（Morphometric map）对下颌第二臼齿（M₂）釉质-齿质连接面的形状和齿冠侧面釉质厚度分布模式进行了量化分析。结果显示：1）东亚中更新世古人类与晚期人属成员（尼安德特人和现代人）存在较明显的形态差别;2）该时段晚期的东亚古人类相对中期直立人在侧面釉质厚度分布规律上具有独特性,并在釉质-齿质连接面的三维形状上与晚期人属成员更加接近。本文在以往对东亚中更新世古人类牙齿内外结构单个性状研究的基础上,使用三维形态测量方法进一步量化了M₂釉质-齿质连接面三维形状和侧面釉质厚度分布模式两项重要特征的变异特点,这对未来该时段同类型牙齿的形态鉴定以及解决东亚中更新世晚期古人类的分类地位具有一定意义。     

高秆野生稻内生固氮细菌多样性

高秆野生稻(Oryza alta)是一种重要的种质资源, 其组织内也蕴藏着非常宝贵的功能微生物资源。本实验采用无氮培养基, 从高秆野生稻中分离到43株内生固氮菌, 结合乙炔还原法测定其固氮酶活性。经固氮酶基因(nifH)的PCR扩增检测, 43株内生固氮菌代表菌株均能扩增出固氮酶基因片段。利用IS-PCR DNA指纹图谱和SDS-PAGE全细胞蛋白电泳图谱将获得的菌株聚类为6个类群(I、II、III、IV、V、VI)。对各个类群的代表菌株(ZF3, ZF8, ZF13, ZF15, ZF24, ZF43)进行16S rRNA基因序列测定, 结果表明, 类群I属于土生拉乌尔菌(Raoultella terrigena), 类群II属于类肺炎克雷伯氏菌类肺炎亚种(Klebsiella quasipnmoniae subsp. quasipneumoniae), 类群III属于越南伯克氏菌(Burkholderia vietnamiensis), 类群IV的菌株代表肠秆菌属的一个类群(Enterobacter sp.), 类群V的菌株属于门多萨假单胞菌(Pseudomonas mendocina), 类群VI归属于固氮植物菌(Phytobacter diazotrophicus)。Biolog聚类结果与IS-PCR指纹图谱类型及SDS-PAGE全细胞蛋白聚类结果一致。Biolog板测定结果显示, 来自不同类群的代表菌株对碳源的利用差异显著, 说明野生稻内多样的内生固氮菌从环境中获取碳源和氮素的适应能力较强。     

中国西藏种子植物区系新资料

本文报道了采自西藏喜马拉雅南坡的8个中国种子植物新记录种以及1个西藏新记录属。前者分别是吉隆牛奶菜(Marsdenia roylei)、塔基棕榈(Trachycarpus takil)、喀西蜂斗草(Sonerila khasiana)、旋花锡生藤(Cissampelos convolvulacea)、吉隆角盘兰(Herminium edgeworthii)、尼泊尔西番莲(Passiflora napalensis)、椭穗姜花(Hedychium ellipticum)和藏南象牙参(Roscoea brandisii); 1个西藏新记录属为箭药藤属(Belostemma) (箭药藤 Belostemma hirsutum)。凭证标本存放于中国科学院西双版纳热带植物园标本馆(HITBC)和西藏自治区高原生物研究所标本室(XZ)。     

山羊重组促卵泡素长效类似物基因在毕赤酵母中表达

为了获得长效FSH制剂, 利用重叠PCR技术将山羊FSH的a, b亚单位, 通过hCGb亚单位羧基末端延长肽(CTP)基因序列的连接, 构建成单链长效类似物基因FSHb-CTP-a。将其克隆至表达载体pPIC9K, 重组载体线性化处理后电转化至毕赤酵母GS115中, 经判型和G418筛选后获得高拷贝菌株His+Mut+。经甲醇诱导表达后, 进行SDS-PAGE和Western blot分析表明: 重组FSHb-CTP-a的转化子可以正确有效地表达目的蛋白, 分子量约为29 kD。放射免疫分析法(RIA)测定表达上清, 高拷贝转化子的平均表达量为91.849 mIU/mL, 显著高于低拷贝转化子的平均37.419 mIU/mL的表达量, 为FSH的结构研究和长效FSH制剂的生产奠定了基础。