Wolfgang Tomek

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In many species, large numbers of macromolecules are accumulated during oocyte growth. The messenger and ribosomal RNAs produced in these cells are far in excess of those necessary to support protein synthesis. Thus, the aim of this study was to elucidate the processes of translational regulation during meiotic maturation. The relationship between(More)
Oocyte selection based on glucose-6-phosphate dehydrogenase (G6PDH) activity has been successfully used to differentiate between competent and incompetent bovine oocytes. However, the intrinsic molecular and subcellular characteristics of these oocytes have not yet been investigated. Here, we aim to identify molecular and functional markers associated with(More)
Prolactin stimulates the expression of milk genes during lactation through the activation of STAT5 transcription factors, which subsequently bind to their cognate target sequence on the promoters. Demethylation of 5methylCpG dinucleotides permits the tissue-specific accessibility of transcription factor-binding sites during development, but remethylation(More)
Since a discrepancy concerning the effects of phytoestrogens on steroidogenesis exists in the literature we investigated the effects of genistein and daidzein on progesterone and estradiol synthesis in cultured primary granulosa cells derived from follicles of porcine ovaries. In this context, the investigation was performed to test the hypothesis that(More)
Mycotoxins are contaminants of animal feed that can impair fertility and cause abnormal fetal development in farm animals. The aim of the present study was to investigate the influence of Fusarium-toxin contaminated feed on cumulus morphology and maturation of pig oocytes. Naturally with the Fusarium-toxins deoxynivalenol (DON) and zearalenone (ZON)(More)
Mycotoxins as contaminants of animal food can impair fertility in farm animals. In the regulation of female fertility the ovarian steroid hormone progesterone (P(4)) plays an important role. In the present study we have investigated the influence of the mycotoxins alternariol (AOH), alternariol mono-methyl ether (AME), and tenuazonic acid (TeA) on cell(More)
The mammalian target of rapamycin (mTor), a Ser/Thr protein kinase, is implicated in the phosphorylation-triggered inactivation of translation repressors, the so-called eukaryotic initiation factor 4E (eIF4E)-binding proteins (4E-BPs). Previous observations in porcine and bovine oocytes revealed an increasing phosphorylation of 4E-BP1 during meiotic(More)
In this study, we document that the overall rate of protein synthesis decreases during in vitro maturation (IVM) of pig oocytes despite enhanced formation of the 5' cap structure eIF4F. Within somatic/interphase cells, formation of the eIF4F protein complex correlates very well with overall rates of protein translation, and the formation of this complex is(More)
Mycotoxins as contaminants of animal food can impair fertility and can cause abnormal fetal development in farm animals. Therefore, the present study has investigated whether derivatives of the mycotoxin zearalenone, alpha-zearalenol (alpha-ZOL) and beta-zearalenol (beta-ZOL), influence progesterone synthesis via cytochrome p450 side chain cleavage enzyme(More)
In somatic cells, the serine/threonine kinase Akt (or protein kinase B) was shown to contribute to processes linked to cellular growth, cell survival and cell cycle regulation. In contrast to these findings, the function of Akt during the meiosis of mammalian oocytes remains to be investigated. We analysed the phosphorylation pattern and the activity of Akt(More)