Phytoplasmas for which 16S rDNA sequences are available have been classified into 20 major phylogenetic groups or subclasses. Further phytoplasmas have been assigned to these groups, according to ...other molecular data such as RFLP analysis of PCR-amplified ribosomal DNA, nucleic acid hybridization, and serological comparison. A total of 75 phytoplasmas were distinguishable among the molecularly characterized phytopathogenic mollicutes
I fitoplasmi, dei quali la sequenza nucleotidica del 16S rDNA era nota, sono stati classificati in 20 gruppi fitogenetici principali. Sulla base di dati ottenuti mediante analisi di RFLP del DNA ribosomale amplificato mediante PCR, ibridazione di acidi nucleici e sierologia, altri fitoplasmi sono stati assegnati ai gruppi suddetti. Un totale di 75 distinti taxa e' stato individuato tra tutti i mollicuti fitopatogeni caratterizzati con metodiche molecolari
Genetics and genomics of chloroplast biogenesis [Zea mays L.] Alsheikh, M. (Iowa State Univ. of Science and Technology, Ames (USA). Dept. of Genetics Development and Cell Biology); Rodermel, S. (Iowa State Univ. of Science and Technology, Ames (USA). Dept. of Genetics Development and Cell Biology)
Maydica,
(2005), Letnik:
50, Številka:
3-4
Journal Article
Plastids are derived from an endosymbiotic event in which a cyanobacterial-like prokaryote was engulfed by a proto-eukaryotic cell. Subsequently, genes were transferred from the DNA of the symbiont ...to that of the nucleus, resulting in a reduction in size of the protoorganellar genome. The presence of organelle and nuclear genetic compartments in the same cell fueled the evolution of mechanisms to coordinate gene expression between plastid and nucleus. Maize mutants have long provided an ideal model for addressing these mechanisms, which include anterograde (nucleus-to-plastid) and retrograde (plastid-to-nucleus) controls. Maize has also played a central role in understanding the structure and function of plastid genome. For instance, the maize plastid genome was the first for which a restriction map was derived. It was subsequently found that plastid DNAs are highly conserved in size and sequence content among higher plants. However, the early notion that plastid DNA is a circular molecule might need to be revised in favour of linear forms. Maize plastid genes were among the first to be cloned and sequenced. These include the genes for the large subunit of Rubisco (rbcL) and the DI protein of PSII (psbA). It is now known that plastid genome contains a complete set of ribosomal RNA genes (23S, 16S, 5S and 4.5S rRNAs) and a full complement of 30 tRNA genes. Most of the about 70 protein coding genes in maize plastid genome are devoted to photosynthetic functions, such as genes for subunits of photosynthetic complexes. Yet, a large number also code for proteins necessary for protein synthesis - ribosomal subunits, RNA polymerase subunits - and other plastid functions, such as the ClpP1 subunit of the Clp protease. The prokaryotic nature of the plastid chromosome has allowed the development of efficient chloroplast transformation strategies for several plant and algal species. However, to date, maize has remained refractory to chloroplast transformation
Provider: - Institution: - Data provided by Europeana Collections- Ciljevi istraživanja:
Povišen izražaj gena p53 i Sesn2 u Rpl24-heterozigotnim miševima ukazuje da p53 regulira njihov fenotip putem ...regulacije mTOR-a i makroautofagije vjerojatno putem Sesn2.
Ciljevi su:
1. Odrediti uzrokuje li p53 patološki fenotip Rpl24-heterozigotnih miševa putem Sesn2.
2. Odrediti aktivnost i važnost makroautofagije u preživljavanju Rpl24-heterozigotnih miševa. 3. Razjasniti molekularne mehanizme putem kojih p53 i Sesn2 reguliraju patološke fenotipove u Rpl24-heterozigotnim embrijima.
Materijali i metode: U istraživanju je korišten miš s heterozigotnom mutacijom u genu za Rpl24, koja rezultira specifičnim fenotipom ovih miševa: slijepoćom, abnormalnosti skeleta, smanjenom masom i zavijenim repom (Bst, engl. Belly Spot and Tail). Izražaj Sesn2 utvrđen je u Rpl24-heterozigotnim embrijima na E10.5 korištenjem kvantitativne reakcije lančanom polimerazom u realnom vremenu (RT-PCR, engl. real time polymerase chain reaction). Da bih testirala mogućnost da p53 uzrokuje patološke fenotipove Rpl24-heterozigotnih miševa putem Sesn2, genetički sam u njima inaktivirala Sesn2. Da bih razlučila potencijalnu važnost makroautofagije i mTOR signalnog puta u Sesn2-ovisnom patološkom fenotipu Rpl24-heterozigotnih miševa, inaktivirala sam jedan alel Atg5, ključnog gena za makroautofagiju. Molekularne mehanizme regulacije preživljavanja Rpl24-heterozigotnih miševa razjasnila sam u modelu gladovanja u ranom poslijenatalnom periodu korištenjem Rpl24-heterozigotnih miševa u kojima je genetički inaktiviran p53, Sesn2 ili jedan alel Atg5.
Rezultati: Dokazano je da p53 uzrokuje kongenitalne malformacije u Rpl24-heterozigotnim miševima putem svog ciljnog gena, Sesn2, te da p53 omogućuje preživljavanje Rpl24-heterozigotnih miševa u ranom poslijenatalnom periodu putem regulacije makroautofagije, koja najvjerojatnije razgradnjom staničnih komponenti osigurava supstrate za sintezu glukoze neophodne za njihovo preživljavanje. p53 i Sesn2 neophodni su za preživljavanje Rpl24-heterozigotnih miševa u ranom poslijenatalnom periodu gladovanja. Međutim, mehanizmi putem kojih p53 i Sesn2 potiču preživljavanje Rpl24-heterozigotnih miševa barem su djelomično različiti.
Zaključci: Dokazano je da p53 uzrokuje kongenitalne malformacije u Rpl24-heterozigotnim miševima putem svog ciljnog gena, Sesn2, te su razjašnjeni molekularni mehanizmi kojima Sesn2 i p53 reguliraju patološke fenotipove u Rpl24-heterozigotnim miševima. Naši rezultati mogu pomoći razumijevanju mehanizama putem kojih p53 uzrokuje patološke promjene u ribosomopatijama, omogućiti bolji uvid u njihovu patogenezu i rezultirati otkrićem potencijalnih ciljeva za liječenje tih bolesti.- Title: Mechanisms by which the p53 tumor suppressor mediates pathological manifestations in Rpl24-heterozygous mice
Objectives:
Upregulation of p53 and Sesn2 in Rpl24-heterozygous mice suggests that p53 regulates pathological manifestations of these mice through Sesn2-dependent regulation of autophagy and mTOR signalling pathway.
Our objectives are:
1. To determine if p53-dependent induction of Sesn2 causes pathological phenotype of Rpl24-heterozygous mice
2. To determine if autophagy is activated and important for the survival of Rpl24-heterozygous mice
3. To determine p53- and Sesn2-dependent molecular mechanisms of regulation of pathological phenotypes of Rpl24-heterozygous mice.
Material and Methods: Spontaneous heterozygous mutation in one allele of ribosomal protein l24 gene (Rpl24) in mice results in defects of the eye, skeleton, mass and coat pigmentation (Bst, Belly Spot and Tail). Sesn2 expression level was determined in Rpl24-heterozygous embryos at E10.5 using quantitative polymerase chain reaction (RT-PCR). To test the possibility that p53-dependent induction of Sesn2 plays a role in pathological phenotypes of Rpl24-heterozygous mice, I genetically inactivated Sesn2 in these mice. To dissect the importance of autophagy and mTOR signalling pathway in Sesn2-dependent pathological phenotype of Rpl24-heterozygous mice, I genetically inactivated one allele of Atg5, important autophagy gene. Molecular mechanisms of survival regulation in Rpl24-heterozygous mice were elucidated in the model of survival under fasting conditions using Rpl24-heterozygous mice with p53, Sesn2 or Atg5 inactivation.
Results: We demonstrate the key role of p53 target gene, Sesn2, in pathological phenotype of Rpl24-heterozygous mice. We show that p53 promotes survival of these mice in early postnatal period through regulation of autophagy, which provides substrates for gluconeogenesis necessary for survival of Rpl24-heterozygous mice. Both, p53 and Sesn2, are indispensable for survival of Rpl24-heterozygous mice in the early postnatal starvation period, but the mechanisms through which these two genes regulate survival of these mice are at least partially different.
Conclusions: We demonstrate the key role of p53 target gene, Sesn2, in pathological phenotype of Rpl24-heterozygous mice, and show the molecular mechanisms by which p53 and Sesn2 regulate these phenotypes.
Our findings may have important implications for understanding p53-dependent mechanisms underlying the pathogenesis of ribosomopathies and could result in the discovery of potential targets for treatment of these diseases.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Mycoplasmalike organisms, now renamed phytoplasmas, are associated with severe plant diseases and, because of the inability to isolate them in pure culture, their identification has been difficult. ...Recently this has become possible, due to the introduction of molecular tools such as DNA probes and PCR/RFLP on conserved ribosomal phytoplasma region (16rDNA) and/or unidentified chromosomal DNA. These approaches provide rapid and reliable means for classification and are also useful in epidemiological studies of phytoplasma associated diseases
Gli organismi micoplasmasimili, ora denominati fitoplasmi, sono associati a gravi malattie delle piante e, per la incapacita' di isolarli in coltura pura, la loro identificazione e' risultata difficoltosa. Recentemente questo e' divenuto possibile per l'introduzione di strumenti di carattere molecolare come le sonde a DNA e la PCR/RFLP sulla regione ribosomiale conservata del fitoplasma (16rDNA) e/o sul DNA cromosomico non identificato. Questi approcci metodologici rendono disponibili metodi rapidi e attendibili per la classificazione e sono pure utili negli studi epidemiologici delle malattie associate ai fitoplasmi
The ribosomal internal transcribed spacers (ITS1 and ITS2) were sequenced from isolates of Botrytis aclada, the causal agent of onion neck rot, and isolates of each of the closely related species B. ...byssoidea and B. squamosa. Alignment of the obtained ITS1 and ITS2 DNA sequences and published sequences from other closely related species showed very little variation between species of Botrytis. Differences were only found at four positions in the ITS1 DNA region and none were found in the ITS2 DNA region. A B. aclada specific primer pair (ITS1ba and ITS2rev) was designed based on one base pair difference, giving a PCR amplification product of 280 base pairs. Using pure fungal cultures it was possible to exclusively amplify DNA from B. aclada
Da isolati di Botrytis aclada, l'agente causale del marciume del colletto della cipolla, sono stati sequenziati gli spacer ribosomiali interni trascritti (ITS1 e ITS2), cosi' come da isolati delle specie strettamente affini B. byssoidea e B. squamosa. L'allineamento delle sequenze del DNA ITS1 e ITS2 ottenute e le sequenze pubblicate relative ad altre specie affini evidenziava una variazione molto piccola fra le specie di Botrytis. Sono state ritrovate differenze solo in quattro posizioni nella regione del DNA ITS1, mentre non ne e' stata ritrovata alcuna nella regione ITS2. E' stato messo a punto un paio di primer specifici di B. aclada (ITS1ba e ITS2rev) in base alla differenza di un paio di basi, ottenendo un prodotto di amplificazione PCR di 280 paia di basi. Utilizzando colture pure di funghi e' stato possibile amplificare il DNA esclusivamente da B. aclada
A rapid and sensitive method has been developed for the differentiation of the species of Seiridium causing cypress canker in the Mediterranean region. The assay was based on the PCR-amplification of ...the Internal Transcribed Spacer 2 (ITS2) region from the ribosomal RNA. Once the piece of DNA was generated, the SSCP technique was applied to detect sequence polymorphism in the investigated fungal species. Minor sequence variations in the single-stranded amplified DNA fragments caused subtle changes in conformation and thus a different mobility on the polyacrylamide gels, allowing the species S. cardinale and S. cupressi to be differentiated. The SSCP assay showed inter-, but not intra-specific differences in the patterns. PCR-SSCP analysis provides a novel method by which to recognise and distinguish important plant pathogenic fungi and should have obvious applications in taxonomic classification
E' stato sviluppato un metodo rapido e sensibile per la differenziazione delle specie di Seiridium cardinale agenti del cancro del cipresso nella regione mediterranea. Il saggio era basato sull'amplificazione PCR della regione Internal Transcriber spacer 2 (ITS2) dell'RNA ribosomiale. Una volta che il pezzo di DNA era stato generato, veniva applicata la tecnica SSCP per determinare il polimorfismo della sequenza nelle specie fungine studiate. Variazioni minori della sequenza nei frammenti di DNA amplificato a elica semplice determinavano variazioni impercettibili nella conformazione e cosi' una mobilita' differente sui gel di poliacrilamide, consentendo la differenziazione delle specie S. cardinale e S. cupressi. Il saggio SSCP evidenziava differenze inter-, ma non intra-specifiche nelle configurazioni. L'analisi PCR-SSCP fornisce un metodo innovativo mediante il quale e' possibile individuare e distinguere importanti funghi patogeni delle piante e dovrebbe avere ovvie applicazioni nella classificazione tassonomica
An indexing procedure for the identification of phytoplasmas in olive trees is presented. Olive trees collected in different locations showing discolorations and malformations have been sampled for ...analysis. The DNA extracted form leaf veins has been amplified in reactions assisted by universal or group-specific primers designed on nucleotide sequences of phytoplasmatal 16S rRNA gene. Amplicons revealing the presence of phytoplasmas of groups 16Sr-IB, -V e -XII have been identified in several samples, also in mixed infections. Although correlation between symptomatology and a given phytoplasma was not feasible, we show that such prokaryotes are ubiquitous in the surveyed areas
Viene presentato un protocollo per il rilevamento di fitoplasmi in piante di olivo. Le indagini sono state condotte su piante di olivo con varie alterazioni morfologiche e cromatiche, raccolte in diverse aree geografiche. Il DNA purificato, estratto da nervature fogliari, e' stato amplificato con l'ausilio di iniziatori di reazione universali o gruppo-specifici costruiti sulla sequenza nucleotidica codificante l'RNA ribosomico 16S dei fitoplasmi. Fitoplasmi appartenenti ai gruppi 16Sr-IB, -V e -XII sono stati riscontrati singolarmente o in infezione mista in numerosi campioni. Pur non potendo associare un determinato fitoplasma ad una sintomatologia ben definita, si puo' comunque affermare che tali procarioti sono presenti in tutte le aree interessate dall'indagine
Prigodom istraživanja djelovanja UV-svjetlosti na razvitak plastida pronađene su u citoplazmi ozračenih stanica produžene zavojite (helikal- ne) nakupine ribosoma, kakve su dosad bile samo rijetko ...opisane. Reproducibilnost eksperimenata govori u prilog mišljenju da opisane tvorevine nisu nastale slučajno.
Interspecific polymorphism of rDNA of Thelazia Bosc 1819 cattle and horse eyeworms Otranto, D; Tarsitano, E. (Bari Univ. (Italy). Dipartimento di Sanita, Patologia, Farmacotossicologia e Benessere degli Animali); Giangaspero, A. (Teramo Univ. (Italy). Istituto di Malattie Infettive)
Atti della Societa' Italiana delle Scienze Veterinarie (Italy),
(1999), Letnik:
53
Conference Proceeding
In order to assess a valuable diagnostic assay for the detection and the identification of the different species of parasites affecting cattle, we are currently developing some molecular approaches ...to charactherize portions of the parasite genome that could be useful for the development of a diagnostic assay. On the basis of the nucleotide sequences of the ribosomal genes of several nematodes, we have synthesised several pairs of primers to be used in the PCR amplification of the genomic DNA of Thelazia gulosa, T. rhodesi, T. skrjabini and T. lacrimalis. One pair of primers revealed length polymorphism which distinguished the four species. The same primers do not amplify the genomic DNA of Musca autumnalis, M larvipara and M. domestica. Amplification products obtained with several other pairs of primers are currently under characterisation in order to identify likely polimorphysms valuable for setting up diagnostic PCR-RFLP based assay
Allo scopo di verificare un metodo diagnostico valido per la scoperta e identificazione delle diverse specie di parassiti che interessano i bovini, stiamo attualmente sviluppando alcuni approcci molecolari per caratterizzare porzioni del genoma dei parassiti che potrebbero essere utili per lo sviluppo di un saggio diagnostico. Sulla base delle sequenze nucleotidiche dei geni ribosomiali di numerosi nematodi, abbiamo sintetizzato numerose paia di primer da utilizzare nell'amplificazione mediante PCR del DNA genomico di Thelazia gulosa, T. rhodesi, T. skrjabini e T. lacrimalis. Un paio di primer evidenziava un polimorfismo di lunghezza che distingueva le quattro specie. Gli stessi primer non amplificano il DNA genomico di Musca autumnalis, M. larvipara e M. domestica. I prodotti di amplificazione ottenuti con numerose altre paia di primer sono attualmente in corso di caratterizzazione allo scopo di identificare probabili polimorfismi interessanti per la messa a punto di un saggio diagnostico basato su PCR-RFLP
Pseudomonas spp. and chromatic alterations in some foods Cantoni, C; Cozzi, M. (Milan Univ. (Italy). Dipartimento di Scienze e Tecnologie Veterinarie per la Sicurezza Alimentare)
Industrie Alimentari (Italy),
(Jun 2002), Letnik:
41, Številka:
415
Magazine Article
P aeruginosa, P putida, P fluorescens and P libanensis clones have been reported here. Some of these strains produce blue and green pigments which alterate the foods. With the help of biomolecular ...methods their identification is made easier
Sono riportati i cloni di Pseudomonas spp. che macchiano di color blu-verde alcuni alimenti. Con l'aiuto di tecniche di biologia molecolare l'identificazione dei vari cloni e' piu' certa
