Les piwi-interacting RNAs (piRNA) interagissent avec les protéines qui font partie de la branche PIWI de la famille des Argonautes. Ils participent à la répression des transposons dans la ligne germinale. Chez la souris, les protéines PIWI sont indispensables pour la fertilité des mâles et sont responsables de la méthylation de l'ADN au niveau des promoteurs des transposons. Les piRNA sont produis à partir de deux mécanismes: la biogenèse primaire et le cycle d'amplification ping-pong. Nous avons fait des études fonctionnelles sur deux protéines qui participent à la voie des piRNA: l'hélicase d'ARN MOV10L1 et l'immunophiline FKBP6. Nous avons décrit le rôle de MOV10L1 en tant que facteur de biogenèse primaire. La disruption génétique du domaine hélicase de MOV10L mène à une activation des transposons et à une perte de la méthylation de l'ADN. Ainsi, les piRNA ne sont pas produits chez le mutant, ce qui suggère que MOV10L1 est essentielle pour la biogenèse des piRNA. Tdrd1 interagit avec les protéines PIWI et joue un rôle dans la voie des piRNA en recrutant quelques facteurs à partir de son domaine MYND N-terminal. Nous avons montré que le domaine MYND de Tdrd1 interagit avec FKBP6, une protéine qui appartient à une famille d'isomérases de prolines qui sont présentes dans des complexes de chaperonnes. Les études biochimiques réalisées indiquent que FKBP6 est inactive et qu'elle utilise son domaine isomérase comme un module structural qui interagit avec les protéines PIWI, alors qu'elle interagit avec Hsp90 avec son domaine TPR. L'analyse d'une souris mutante pour fkbp6 a révélé une dérépression des transposons et une perte de la méthylation de l'ADN, mais peu d'effets sur la biogenèse primaire. Ces résultats sont en accord avec un rôle de FKBP6 en aval de Tdrd1, et nous pouvons penser que ce rôle pourrait être le recrutement de Hsp90 pour participer au cycle d'amplification ping-pong.

The graduation thesis deals with history of winery and the culture of wine in the Czech Republic. In the first part the author focused on attribute of wineyard Pustina, its original and climatic charakteristics. There is a description od selected variaties of grapevine, which were used as experimental plants. The practical part of thesis is based on the result of experimental planting of chosen varieties of grapevine as recommendation for another wineyards with the same weather conditions as Pustina.

This thesis deals with evaluation of analytical and organoleptic properties of new PIWI varieties. The aim of the thesis is to describe and evaluate the suitability of selected PIWI varieties for cultivation in the Czech Republic winery. In the thesis fifty-two bottles of varieties and cuvée wines from the Czech Republic, Germany, the Netherlands, Denmark, Poland and Sweden are analysed, tasted, evaluated and briefly described. All nineteen tested varieties should be recommended to certain growing conditions in the Czech Republic. The top rated varieties with three or more samples are PIWI varieties of Cabernet Blanc, Solaris and Hibernal. All varieties proved the ability to produce on average up to above average harmonious wines which can be the basis for winemaking in organic viticulture in the Czech Republic.

No description available.

Mosquito-borne diseases remain a significant burden on global public health. Maintenance of mosquito-borne viruses in nature requires a biological transmission cycle that involves alternating virus replication in a susceptible vertebrate and mosquito host. Although infection of the vertebrate host is acute and often associated with disease, continual transmission of these viruses in nature depends on the establishment of a persistent, nonpathogenic infection in the mosquito vector. It is well known that invertebrates rely on small RNA pathways as an adaptive antiviral defense. The canonical antiviral response in these organisms involves dicer enzymes that cleave viral double-stranded RNA replicative intermediates (RIs) into small interfering RNAs (siRNAs; ~21-24 nucleotides). One strand of the siRNA duplex guides the targeting and destruction of complementary viral RNAs when loaded and retained in a multi-protein complex called the RNA-induced silencing complex. Here, we show that mosquito vectors mount a redundant double defense against virus infection mediated by two different small RNA pathways. Specifically, we demonstrate that in addition to a canonical antiviral response mediated by siRNAs, virus infection of the mosquito soma also triggers an antiviral immune pathway directed by ping-pong-dependent PIWI-interacting RNAs (piRNAs; ~24-30 nucleotides). The complexity of mosquito antiviral immunity has important implications for understanding how viruses both induce and modulate RNA-silencing responses in mosquito vectors. In mammals, viral RIs induce a range of relatively nonspecific antiviral responses. However, it remains unclear if viral RIs also trigger RNA silencing in mammals. Mosquito-borne viruses represent an ideal model for addressing this question as their transmission cycles involve alternating replication in mammalian and invertebrate hosts. Although we report identifying a subset of virus-derived small RNAs that appear to be products of RNA silencing in two mammalian cell lines infected with the mosquito-borne chikungunya virus (CHIKV), our studies suggest these small RNAs have little biological relevance in combating virus infections. Thus, while the accumulation of virus-derived siRNAs is essential to the survival of mosquitoes infected with CHIKV, they appear to have little functional significance in mammalian antiviral immunity. / Ph. D.

Development, Growth & Differentiation: This is the peer reviewed version of the following article: Heterogeneity of chromatoid bodies in adult pluripotent stem cells of planarian Dugesia japonica, which has been published in final form at [Link to final article using the DOI10.1111/dgd.12268]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. / 京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19540号 / 理博第4200号 / 新制||理||1603(附属図書館) / 32576 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 阿形 清和, 教授 森 和俊, 教授 大野 睦人 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Argonaute proteins are small DNA/RNA-guided endonucleases found in all domains of life. In animals, small RNAs of length 21–35 nucleotides direct the PIWI-clade of Argonautes to silence complementary target RNAs; these are called PIWI-interacting RNAs (piRNAs). During spermatogenesis in mice, piRNA-guided PIWI proteins, MIWI2, MILI, and MIWI, silence transposons, regulate expression of protein-coding genes and are necessary for fertility. A working endonuclease activity of MIWI and MILI is essential to complete spermatogenesis. Yet, both MIWI and MILI produce weak and slow target cleavage in vitro, thwarting biochemical examination of the silencing step. Here, we find that PIWI proteins require an auxiliary protein to efficiently cleave their targets, unlike any other known Argonaute. Gametocyte Specific Factor 1 (GTSF1) is a conserved zinc-finger protein essential for fertility and piRNA-directed silencing. We show GTSF1 accelerates the pre-steady-state rate of target cleavage by MIWI and MILI; this role of GTSF1 is also preserved in insects. A critical step in GTSF1 mechanism entails binding RNA. GTSF1 allowed detailed kinetic analyses of catalytic PIWIs: they require extensive 3′ complementarity between the guide and target to efficiently cleave them, but this base-pairing also limits turnover. Interestingly, within a species, different PIWI proteins have unique kinetic properties. In sum, our findings provide molecular mechanisms of GTSF1 function and target silencing by PIWIs as well as a useful method for future studies.

This diploma thesis deasl with the chemical charakterization of wine from selected PIWI varieties. The theoretical part describes the general origin and reason for breeding PIWI varieties, a closer characterization of selected three PIWI varieties, Johaniter, Hibernal and Solaris. The next part is devoted to the description of analytical methods that were used to determine the chemical characteristics. The experimental part is developed to the determination of chemical characteristics, namely general characteristics such as alcohol, total phenols, phenolic substances, volatile substances and elemental composition. The results show that are differences between wines from selected PIWI varieties in therms of chemical composition. The most represented organic acid was in the range of 735,1-1286,2mg/l malic acid. This was followed by acetic in the range of 100-400mg/l. The antioxidant activity was determined in the range of 0,2988-0,9683 mmol/l of Trollox and content of total phenols 273,5-390,3mg/l. Of the phenolic substances, gallic acid was the most represented, ranging from 6,9-13,9mg/l. As another, abundant phenolic substances, catechin in the range of 1,6-6,0mg/l was detected. Of the determined elements, phosphorus in the range of 165,4-450,5mg/l was the most represented. Representatives of ethyl ester, ethyl acetate, decanoic acid ethyl acetate and hexanoic acid ethyl ester, were detected as the most abundant volatiles. From the measured data it was evident that wines from PIWI varieties different from standard varieties, especially in the profile of aromatic substances.

PiRNAs and their Piwi family protein partners are part of a germline specific epigenetic regulatory mechanism essential for proper spermatogenesis, silencing of transposable elements, and maintaining germline genome integrity, yet their role in the response of the male germline to genotoxic stress is unknown. Ionizing radiation (IR) is known to cause transgenerational genome instability that is linked to carcinogenesis. Although the molecular etiology of IR-induced transgenerational genomic instability is not fully understood, it is believed to be an epigenetically mediated phenomenon. IR-induced alterations in the expression pattern of key regulatory proteins involved in the piRNA pathway essential for paternal germline genome stability may be directly involved in producing epigenetic alterations that can impact future generations. Here we show whole body and localized X-irradiation leads to significant altered expression of proteins that are necessary for, and intimately involved in, the proper functioning of the germline specific piRNA pathway in mice and rats. In addition we found that IR-induced alterations to piRNA pathway protein levels were time and dose dependent. / ix, 123 leaves : ill. (some col.) ; 29 cm