TY - JOUR
T1 - Expression of nucleolar-related proteins in porcine preimplantation embryos produced in vivo and in vitro.
AU - Bjerregaard, Bolette
AU - Wrenzycki, Christine
AU - Strejcek, Frantisek
AU - Laurincik, Jozef
AU - Holm, Peter
AU - Ochs, Robert L
AU - Rosenkranz, Christine
AU - Callesen, Henrik
AU - Rath, Detlef
AU - Niemann, Heiner
AU - Maddox-Hyttel, Poul
PY - 2004
Y1 - 2004
N2 - The expression of nucleolar-related proteins was studied as an indirect marker of the ribosomal RNA (rRNA) gene activation in porcine embryos up to the blastocyst stage produced in vivo and in vitro. A group of the in vivo-developed embryos were cultured with alpha-amanitin to block the de novo embryonic mRNA transcription. Localization of proteins involved in the rRNA transcription (upstream binding factor [UBF], topoisomerase I, RNA polymerase I [RNA Pol I], and the RNA Pol I-associated factor PAF53) and processing (fibrillarin, nucleophosmin, and nucleolin) was assessed by immunocytochemistry and confocal laser-scanning microscopy, and mRNA expression was determined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). These findings were correlated with ultrastructural data and autoradiography following 20-min [3H]uridine incubation. Additionally, expression of the pocket proteins pRb and p130, which are involved in cell-cycle regulation, was assessed by semiquantitative RT-PCR up to the blastocyst stage. Toward the end of third cell cycle, the nuclei in non-alpha-amanitin-treated, in vivo-produced embryos displayed different stages of transformation of the nuclear precursor bodies (NPBs) into fibrillogranular nucleoli associated with autoradiographic labeling. However, on culture with alpha-amanitin, NPBs were not transformed into a fibrillogranular nucleolus during this cell cycle, demonstrating that embryonic nucleogenesis requires de novo mRNA transcription. Moreover, immunolocalization of RNA Pol I, but not of UBF, and the mRNA expression of PAF53 and UBF were significantly reduced or absent after culture with alpha-amanitin, indicating that RNA Pol I, PAF53, and presumably, UBF are derived from de novo embryonic transcription. Embryonic genomic activation was delayed in porcine embryos produced in vitro compared to the in vivo-derived counterparts with respect to mRNAs encoding PAF53 and UBF. Moreover, differences existed in the mRNA expression patterns of pRb between in vivo- and in vitro-developed embryos. These findings show, to our knowledge for the first time, a nucleolus-related gene expression in the preimplantation porcine embryo, and they highlight the differences in quality between in vivo and in vitro-produced embryos.
AB - The expression of nucleolar-related proteins was studied as an indirect marker of the ribosomal RNA (rRNA) gene activation in porcine embryos up to the blastocyst stage produced in vivo and in vitro. A group of the in vivo-developed embryos were cultured with alpha-amanitin to block the de novo embryonic mRNA transcription. Localization of proteins involved in the rRNA transcription (upstream binding factor [UBF], topoisomerase I, RNA polymerase I [RNA Pol I], and the RNA Pol I-associated factor PAF53) and processing (fibrillarin, nucleophosmin, and nucleolin) was assessed by immunocytochemistry and confocal laser-scanning microscopy, and mRNA expression was determined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). These findings were correlated with ultrastructural data and autoradiography following 20-min [3H]uridine incubation. Additionally, expression of the pocket proteins pRb and p130, which are involved in cell-cycle regulation, was assessed by semiquantitative RT-PCR up to the blastocyst stage. Toward the end of third cell cycle, the nuclei in non-alpha-amanitin-treated, in vivo-produced embryos displayed different stages of transformation of the nuclear precursor bodies (NPBs) into fibrillogranular nucleoli associated with autoradiographic labeling. However, on culture with alpha-amanitin, NPBs were not transformed into a fibrillogranular nucleolus during this cell cycle, demonstrating that embryonic nucleogenesis requires de novo mRNA transcription. Moreover, immunolocalization of RNA Pol I, but not of UBF, and the mRNA expression of PAF53 and UBF were significantly reduced or absent after culture with alpha-amanitin, indicating that RNA Pol I, PAF53, and presumably, UBF are derived from de novo embryonic transcription. Embryonic genomic activation was delayed in porcine embryos produced in vitro compared to the in vivo-derived counterparts with respect to mRNAs encoding PAF53 and UBF. Moreover, differences existed in the mRNA expression patterns of pRb between in vivo- and in vitro-developed embryos. These findings show, to our knowledge for the first time, a nucleolus-related gene expression in the preimplantation porcine embryo, and they highlight the differences in quality between in vivo and in vitro-produced embryos.
U2 - 10.1095/biolreprod.103.021683
DO - 10.1095/biolreprod.103.021683
M3 - Journal article
C2 - 14585813
SN - 0006-3363
VL - 70
SP - 867
EP - 876
JO - Biology of Reproduction
JF - Biology of Reproduction
IS - 4
ER -