Cloning and expression of two new prolactin-related proteins,prolactin-related protein-VIII and -IX,in bovine placenta

Background  

Prolactin-related proteins (PRPs) are specific proteins of the growth hormone/prolactin (GH/PRL) family in bovine placenta. This study reports the identification and sequencing of a full-length cDNA for two new members of bovine PRPs, bPRP-VIII and -IX, and their localization and quantitative expression in bovine placenta.     

Cloning,expression, and localization of a new member of a Paracentrotus lividus cell surface multigene family

We have isolated and characterized a cDNA clone corresponding to a new member of bep (butanol, extracted, proteins) Paracentrotus lividus multigene family coding for cell surface proteins. The cDNA, called bep3, encodes a 370 amino acid protein and shares the same structural organization in the coding region with other members of the same gene family already characterized. Expression of this clone studied by Northern blot and by whole mount hybridization shows that the bep3 messenger is transcribed during oogenesis and utilized till the gastrula stage, whereas at the prism stage, unlike other members of the same gene family, new synthesis of messenger occurs. By whole mount hybridization spatial distribution of bep3 messenger in egg and embryos is established. This messenger appears located in the animal half of the unfertilized egg and moves to the cortical zone after fertilization; it is not present in the structures derived by the vegetal part of the embryo, such as the micromeres of the 16-cell stage, the primary mesenchyme cells of the blastula, and the primary intestine of the gastrula. At the prism stage instead, hybridization of bep3 messenger is restricted to the part of the embryo that will give origin to the oral region as successively confirmed by hybridization at the pluteus stage. The result of whole mount hybridization was confirmed by Northern blot hybridization of separated meso-macromere and micromere RNAs. A Southern blot experiment demonstrates that bep3 is codified by a single copy gene. Conservation of the bep multigene family in several Mediterranean and Japanese sea urchin species has also been analyzed. © 1996 Wiley-Liss, Inc.     

芹菜NHL-like蛋白基因克隆与表达分析

植物生长发育过程中会遭遇各种病原物的攻击,植物为了应对这些危害并适应外界的生存竞争,逐渐演化出了复杂的防御机制。NHL基因家族庞大,部分NHL基因受病原物诱导后会过量表达,增强植物对多种病原菌的抗性,是与植物防御机制密切相关的蛋白。本研究以津南实芹和美国西芹2个芹菜品种为试验材料,分别克隆出NHL-like蛋白基因AgNHL。序列分析表明,上述2种芹菜的AgNHL基因序列均含636 bp的开放阅读框,编码211个氨基酸。2种芹菜碱基序列,只有第36位不同,津南实芹为T,美国西芹为C,2种碱基序列相似性高达99.84%,编码的氨基酸序列相同。进化分析显示,2种芹菜的NHL-like蛋白与葡萄、大豆等植物的相似度较高,在第80~185氨基酸间含一个LEA-2蛋白保守结构域。荧光定量PCR结果表明,AgNHL基因主要在芹菜茎中表达,根中表达量最低,有明显组织特异性,品种差异也很显著。对2种芹菜分别进行4℃低温、38℃高温、20%PEG处理、0.2 mol/L NaCl处理2 h表达分析显示,低温、盐处理下该基因表达量明显上升。     

Sequence and expression analysis of a Xenopus laevis cDNA which encodes a homologue of mammalian 14-3-3 zeta protein

We report the cloning and characterisation of a cDNA that encodes a novel member of the Xenopus laevis 14-3-3 protein family. Sequence analysis reveals that the cDNA-encoded protein shares 84% identity with the rat, human or sheep 14-3-3ζ isoform, and between 66% and 77% identity with bovine, human or rat β, bovine γ, human τ, Drosophila 14-3-3 and a previously isolated Xenopus member. The corresponding mRNA is present in all adult tissues examined with the highest levels in the brain. Although the gene is expressed throughout embryogenesis, higher levels of mRNA accumulate after gastrulation. Whole-mount in situ hybridisation on tailbud stage embryo reveals strong expression of the gene in the head, optic vesicles, spinal cord and branchial arches with weaker expression in the somites. In addition, expression along the notochord is observed at stage 45 (tadpole). This spatial and temporal expression profile along with recent studies implicating the importance of 14-3-3 proteins in the regulation of signal transduction pathways argues for a key role of this isoform in embryonic development.     

Cloning, expression and processing of the CP2 neuropeptide precursor of Aplysia.

The cDNA sequence encoding the CP2 neuropeptide precursor is identified and encodes a single copy of the neuropeptide that is flanked by appropriate processing sites. The distribution of the CP2 precursor mRNA is described and matches the CP2-like immunoreactivity described previously. Single cell RT-PCR independently confirms the presence of CP2 precursor mRNA in selected neurons. MALDI-TOF MS is used to identify additional peptides derived from the CP2 precursor in neuronal somata and nerves, suggesting that the CP2 precursor may give rise to additional bioactive neuropeptides.     

In situ Western hybridization: a new,highly sensitive technique to detect foreign and endogenous protein distribution in rice seeds

We have developed a highly sensitive in situ Western hybridization technique to study tissue-specific expression of foreign and endogenous genes in transgenic and non-transformed rice seed. The expression pattern of the soybean ferritin gene directed by a rice glutelin gene promoter, GluB-1, in transgenic rice seed revealed by this method was exactly the same as that revealed by immunological tissue printing but much clearer than the latter, and corresponded well to the results of GluB-1 promoter characterization studies. This method provides an alternative choice for studying the tissue-specific expression of a promoter, omitting the complicated transgenic procedure. The method can also be used to study the expression and accumulation pattern of endogenous genes, such as glutelin and prolamine genes, in non-transformed plants.Abbreviations DAF Days after flowering - GUS -Glucuronidase - GFP Green fluorescent protein - TBS Tris-HCl-buffered saline - TBST TBS with Tween-20Communicated by H. Ebinuma     

Molecular cloning and gene expression of Foxl2 in the Nile tilapia, Oreochromis niloticus

A Foxl2 cDNA was cloned from the Nile tilapia ovary by RT-PCR and subsequent RACE. Alignment of known Foxl2 sequences from vertebrates confirmed the conservation of the Foxl2 open reading frame and protein sequences, especially the forkhead domain and C-terminal region, while some homopolymeric runs of amino acids are found only in mammals but not in non-mammalian vertebrates. RT-PCR revealed that Foxl2 is expressed in the tilapia brain (B), pituitary (P), gill, and gonads (G), with the highest level of expression in the ovary, reflecting the involvement of Foxl2 in B-P-G axis. Northern blotting and in situ hybridization also revealed an evident sexual dimorphic expression pattern in the gonads. Foxl2 mRNA was mainly detected in the granulosa cells surrounding the oocytes. The ovarian expression of Foxl2 in tilapia begins early during the differentiation of the gonads and persists until adulthood, implying the involvement of Foxl2 in fish gonad differentiation and the maintenance of ovarian function.     

Mouse retinol binding protein gene: Cloning,expression and regulation by retinoic acid

A full-length cDNA clone encoding the retinol binding protein (RBP) was isolated from a mouse liver cDNA library by hybridization screening. The nucleotide sequence of murine RBP is 85 and 95% homologous to that of human and rat RBP, respectively, with a deduced amino acid sequence 83% homologous to both species. Analysis of the tissue expression pattern of RBP mRNA in the female mouse indicated relatively abundant expression in the liver, with lesser amounts in extrahepatic tissues including adipose, kidney, spleen and uterus, suggesting that these tissues may have a significant role in retinol homeostasis. Mouse liver cell RBP regulation by retinoids was also investigated. Both all-trans retinoic acid (AT-RA) and 9-cis retinoic acid (9c-RA) induced RBP mRNA expression in a dose- and time-dependent manner. Maximal levels (up to 4-fold above controls) were observed at 48h following treatment of both mouse hepatoma cells in vitro and in vivo in mice receiving a single, oral dose of either retinoid. Interestingly, 9c-RA was more potent at RBP induction in both in vivo and in vitro systems. Given the extent and temporal pattern of RBP induction, we suggest that the RA-mediated increase in liver RBP is part of a cellular protection mechanism. Increased levels of RBP would facilitate sequestration and possibly cellular export of RA in cells receiving prolonged exposure to high levels of RA, thus minimizing toxicity.     

棉铃虫感觉神经元膜蛋白基因克隆和表达

从棉铃虫Helicoverpa armigera触角中克隆了一条全长1 690 bp的cDNA序列,该序列阅读框全长1 572 bp,编码523个氨基酸残基,序列中有2个跨膜区,具有昆虫感觉神经元膜蛋白（sensory neuron membrane protein, SNMP）的典型特征。SNMP与已报道的其他昆虫的感觉神经元蛋白的氨基酸序列有很高的同源性。半定量RT-PCR研究结果显示,SNMP在棉铃虫中不仅在触角中表达,也在去掉触角的头、足中表达。但是在触角中的表达量最高,在雌雄触角中的表达量差异不显著。在喙、下颚须和下唇须中也有表达。SNMP在卵、蛹和成虫体内也都有表达,但在卵中表达量相对较低。将SNMP编码区克隆到表达载体pET21b中,成功地进行了原核表达,表达出带有6个组氨酸标签的重组蛋白。     

Cloning, expression and processing of the CP2 neuropeptide precursor of Aplysia

The cDNA sequence encoding the CP2 neuropeptide precursor is identified and encodes a single copy of the neuropeptide that is flanked by appropriate processing sites. The distribution of the CP2 precursor mRNA is described and matches the CP2-like immunoreactivity described previously. Single cell RT-PCR independently confirms the presence of CP2 precursor mRNA in selected neurons. MALDI-TOF MS is used to identify additional peptides derived from the CP2 precursor in neuronal somata and nerves, suggesting that the CP2 precursor may give rise to additional bioactive neuropeptides.     

游仆虫Rab蛋白基因的克隆表达与纯化

为对单细胞原生动物纤毛虫中Rab蛋白的功能进行研究 ,进而探讨以胞吞和胞吐为主要物质交换途径的纤毛虫中囊泡定向运输的机理 .利用PCR技术从游仆虫大核DNA及cDNA中扩增出rab基因 ,并进行了序列分析 ,该基因全长为 783bp ,两端为端粒序列 ,编码框为 6 2 4bp ,编码 2 0 7个氨基酸 ,开放读框中有 3个TGA ,在此编码半胱氨酸 .利用定点突变将rab基因中 3个TGA突变为通用半胱氨酸密码子TGC .将游仆虫Rab蛋白基因构建于原核表达载体pGEX 4T 2中 ,得到的重组质粒pGEX Eorab1转化至大肠杆菌BL2 1(DE3)中 ,IPTG诱导表达 .表达产物与抗GST抗体在 4 9kD处有很强的交叉反应 .融合蛋白GST EoRab1通过亲和层析柱纯化和凝血酶的切割 ,再经两步纯化得到电泳纯的游仆虫Rab蛋白 .     

Cloning and expression of zebrafish neuronal nicotinic acetylcholine receptors

We propose to use the zebrafish (Danio rerio) as a vertebrate model to study the role of neuronal nicotinic acetylcholine receptors (nAChR) in development. As a first step toward using zebrafish as a model, we cloned three zebrafish cDNAs with a high degree of sequence similarity to nAChR beta3, alpha2 and alpha7 subunits expressed in other species. RT-PCR was used to show that the beta3 and alpha2 subunit RNAs were present in zebrafish embryos only 2-5hours post-fertilization (hpf) while alpha7 subunit RNA was not detected until 8hpf, supporting the differential regulation of nAChRs during development. In situ hybridization was used to localize zebrafish beta3, alpha2, and alpha7 RNA expression. nAChR binding techniques were used to detect the early expression of two high-affinity [3H]-epibatidine binding sites in 2 days post-fertilization (dpf) zebrafish embryos with IC(50) values of 28.6pM and 29.7nM and in 5dpf embryos with IC(50) values of 28.4pM and 8.9nM. These studies are consistent with the involvement of neuronal nAChRs in early zebrafish development.     

家蚕羧酸酯酶基因Bmae35的克隆、 序列分析及表达

昆虫羧酸酯酶是一类能对外源化合物解毒和气味分子降解的重要酶系。本研究选取在家蚕Bombyx mori幼虫嗅觉感器中有表达, 并与蛀茎夜蛾Sesamia nonagrioides触角酯酶基因Snon-EST可能为直系同源基因的Bmae35进行克隆和外源表达研究。结果表明： 该基因编码区长1 581 bp, 共编码526个氨基酸。与其他昆虫触角酯酶的多序列比对分析发现, Bmae35编码的蛋白具有酯酶活性必须的催化残基Ser191, Glu313和His429, 也保持着α-酯酶家族特征基序Gly-x-Ser-x-Gly。RT-PCR分析显示, Bmae35在家蚕5龄第3天各组织中均有表达, 其中在头、 脂肪体、 马氏管、 体壁和丝腺中的表达量较高。Bmae35在雌蛾性信息腺中表达, 并与性信息素合成呈正相关, 暗示其在信息素合成中起重要作用。构建Bmae35与pET28(a) 重组载体, 经异丙基-β-D-硫代半乳糖苷诱导,电泳检测发现该基因以包涵体形式表达, 以镍亲和层析柱纯化, Western blotting鉴定证实Bmae35在大肠杆菌Escherichia coli中正确表达并得以纯化。本实验通过对家蚕Bmae35基因的克隆、 原核表达与纯化, 为进一步深入研究其表达定位和气味降解等功能奠定基础。