Control of gene expression at the onset of bovine embryonic development

• Published in: Biology of reproduction 1999-11, Vol.61 (5), p.1198-1207
• Main Authors: Memili, E, First, N.L
• Format: Article
• Language: English
• Subjects: acetylation; Acylation; alpha-amanitin; Animals; aphidicolin; Aphidicolin - pharmacology; Biological and medical sciences; Cattle; Cells, Cultured; Chromatin - metabolism; DNA replication; DNA Replication - drug effects; Early stages. Segmentation. Gastrulation. Neurulation; Electrophoresis, Polyacrylamide Gel; embryo (animal); embryo culture; embryogenesis; Embryology: invertebrates and vertebrates. Teratology; Embryonic and Fetal Development - genetics; Enzyme Inhibitors - pharmacology; Female; Fertilization in Vitro; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental - genetics; Gene Expression Regulation, Developmental - physiology; histones; Histones - chemistry; inhibition; inhibitors; messenger RNA; Oocytes - drug effects; Oocytes - metabolism; Protein Biosynthesis - genetics; protein synthesis; RNA - biosynthesis; transcription (genetics); Transcription, Genetic - genetics; Transcriptional Activation; translation; tricostatin a; Uridine - metabolism; zygote; Zygote - drug effects; Zygote - metabolism
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod61.5.1198

The objective of this study was to examine the timing and mechanisms involved in transcription initiation in bovine embryos. Transcriptional activity and its regulation were explored by labeling 1-cell zygotes and 2-cell embryos with [ 3 H]uridine in the presence or absence of alpha-amanitin, aphidicolin, and tricostatin A (TSA) (inhibitors of mRNA synthesis, DNA replication, and histone deacetylases, respectively) followed by a total RNA isolation and determination of [ 3 H]uridine incorporation. We also analyzed translation of zygotic/embryonic mRNAs by labeling zygotes and 2-cell embryos with [ 35 S]methionine in the presence or absence of alpha-amanitin, aphidicolin, and TSA followed by two-dimensional PAGE and autoradiography. We show that bovine 1-cell zygotes and 2-cell embryos are transcriptionally and translationally active. The first and second rounds of DNA replication are important regulators of early gene expression as the inhibition of DNA replication resulted in a dramatic decrease in both transcriptional and translational activity. Moreover, acetylation of histones plays an important role in this early gene activation at the onset of embryonic development in the cow.