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Full-Text Articles in Obstetrics and Gynecology

Differential Involvement Of Na(+),K(+)-Atpase Isozymes In Preimplantation Development Of The Mouse., D J Macphee, D H Jones, K J Barr, D H Betts, A J Watson, G M Kidder Jun 2000

Differential Involvement Of Na(+),K(+)-Atpase Isozymes In Preimplantation Development Of The Mouse., D J Macphee, D H Jones, K J Barr, D H Betts, A J Watson, G M Kidder

Obstetrics & Gynaecology Publications

Na(+),K(+)-ATPase plays an essential role in mammalian blastocoel formation (cavitation) by driving trans-epithelial sodium transport. Previously, the alpha1 and beta1 subunit isoforms of this enzyme were identified in preimplantation mouse embryos and were assumed to be responsible for this function. Here we show that mRNAs encoding an additional alpha subunit isoform (alpha3) and the remaining two beta subunit isoforms are also present in preimplantation embryos. Whereas alpha3 mRNA accumulates between the four-cell and the blastocyst stages and thus results from embryonic transcription, the same could not be demonstrated for beta2 and beta3 mRNAs. Immunoblot analyses confirmed that these subunits are …


Trophectoderm Differentiation In The Bovine Embryo: Characterization Of A Polarized Epithelium., L C Barcroft, A Hay-Schmidt, A Caveney, E Gilfoyle, E W Overstrom, P Hyttel, A J Watson Nov 1998

Trophectoderm Differentiation In The Bovine Embryo: Characterization Of A Polarized Epithelium., L C Barcroft, A Hay-Schmidt, A Caveney, E Gilfoyle, E W Overstrom, P Hyttel, A J Watson

Obstetrics & Gynaecology Publications

Blastocytst formation is dependent on the differentiation of a transporting epithelium, the trophectoderm, which is coordinated by the embryonic expression and cell adhesive properties of E-cadherin. The trophectoderm shares differentiative characteristics with all epithelial tissues, including E-cadherin-mediated cell adhesion, tight junction formation, and polarized distribution of intramembrane proteins, including the Na-K ATPase. The present study was conducted to characterize the mRNA expression and distribution of polypeptides encoding E-cadherin, beta-catenin, and the tight junction associated protein, zonula occludens protein 1, in pre-attachment bovine embryos, in vitro. Immunocytochemistry and gene specific reverse transcription--polymerase chain reaction methods were used. Transcripts for E-cadherin and …


Transient Expression Of A Translation Initiation Factor Is Conservatively Associated With Embryonic Gene Activation In Murine And Bovine Embryos., P A De Sousa, A J Watson, R M Schultz Oct 1998

Transient Expression Of A Translation Initiation Factor Is Conservatively Associated With Embryonic Gene Activation In Murine And Bovine Embryos., P A De Sousa, A J Watson, R M Schultz

Obstetrics & Gynaecology Publications

In the present study the abundance of mRNAs for eukaryotic translation initiation factors eIF-1A (formerly known as eIF-4C), -2alpha, -4A, -4E, and -5 was examined in in vivo-derived mouse embryos throughout preimplantation development using a semiquantitative reverse transcription-polymerase chain reaction assay. Although the mRNA profile for each gene is unique, only mRNA for eIF-1A transiently increases during embryonic gene activation (EGA) at the 2-cell stage, and this was confirmed by an independent hybridization-based assay. In in vitro-developed bovine embryos, mRNA for eIF-1A was transiently detected at the 8-cell stage, when the major activation of the genome occurs in this species. …


Expression Of Genes Encoding Antioxidant Enzymes In Preimplantation Mouse And Cow Embryos And Primary Bovine Oviduct Cultures Employed For Embryo Coculture., M B Harvey, M Y Arcellana-Panlilio, X Zhang, G A Schultz, A J Watson Sep 1995

Expression Of Genes Encoding Antioxidant Enzymes In Preimplantation Mouse And Cow Embryos And Primary Bovine Oviduct Cultures Employed For Embryo Coculture., M B Harvey, M Y Arcellana-Panlilio, X Zhang, G A Schultz, A J Watson

Obstetrics & Gynaecology Publications

Preimplantation embryos from a variety of mammalian species contrast markedly in their response to culture in vitro. Murine preimplantation embryos display a wider tolerance than other mammalian species to culture environments, and this has contributed to the development of several effective defined culture media. Embryo coculture on somatic cells remains the most effective method of supporting reasonable rates of bovine preimplantation development in vitro. The patterns of gene expression for several antioxidant enzymes during preimplantation murine and bovine development were examined by use of the reverse transcription-polymerase chain reaction technique to determine whether the differential developmental capacity of mammalian preimplantation …


How To Make A Blastocyst., A J Watson, G M Kidder, G A Schultz Oct 1992

How To Make A Blastocyst., A J Watson, G M Kidder, G A Schultz

Obstetrics & Gynaecology Publications

Several of the new reproductive technologies have been cultivated from our current understanding of the genetic programming and cellular processes that are involved in the major morphogenetic events of mammalian preimplantation development. Research directed at characterizing the patterns of gene expression during early development has shown that the embryo is initially under maternal control and later superseded by new transcriptional activity provided by the activation of the embryonic genome. Several embryonic transcripts encoding: (i) growth factors, (ii) cell junctions, (iii) plasma membrane ion transporters, and (iv) cell adhesion molecules have been identified as contributing directly to the progression of the …