Expression of proto-oncogenes in bovine preimplantation blastocysts.
Proto-oncogenes are involved in the regulation of gene expression, for example after ligand binding to growth factor receptors. Expression of the proto-oncogenes c-fos, c-jun, c-ha-ras and c-myc was studied in in vivo grown and in vitro cultured bovine preimplantation blastocysts employing RT-PCR, ribonuclease protection assay and immunohistochemistry. Thirteen- and 14- day-old preimplantation blastocysts, i.e. stages before and during trophoblast elongation, were used. In in vivo-grown blastocysts c-fos, c-jun and c-ha-ras transcripts as well as c-Fos, c-Jun and c-Myc proteins were detected in all stages studied. Cultured blastocysts were treated with 10 nM epidermal growth factor and 10 nM transforming growth factor-alpha simultaneously. Epidermal growth factor and transforming growth factor-alpha treatment induced c-fos mRNA and c-Myc protein expression. The induction of downstream targets of the epidermal growth factor receptor by epidermal growth factor and transforming growth factor-alpha indicates a functional epidermal growth factor signal transduction pathway in elongating bovine blastocysts.
Tetens
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F
Department of Anatomy and Cell Biology, Martin Luther University Faculty of Medicine, Halle (Saale), Germany.
Kliem
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A
Tscheudschilsuren
G
G
Navarrete Santos
A
A
Fischer
B
B
D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002417:Cattle; D010064:Embryo Implantation / Q000187:drug effects / Q000502:physiology*; D004622:Embryo, Mammalian; D004717:Endometrium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D016760:Proto-Oncogene Proteins c-fos / Q000187:drug effects / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000187:drug effects / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc / Q000187:drug effects / Q000235:genetics; D011519:Proto-Oncogenes / Q000187:drug effects / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000187:drug effects / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D016211:Transforming Growth Factor alpha / Q000378:metabolism / Q000494:pharmacology
D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor