Promoter analysis of the rabbit POU5F1 gene and its expression in preimplantation stage embryos
 

Background

The POU5F1 gene encodes the octamer-binding transcription factor-4 (Oct4). It is crucial in the regulation of pluripotency during embryonic development and widely used as molecular marker of embryonic stem cells (ESCs). The objective of this study was to identify and to analyse the promoter region of rabbit POU5F1 gene; furthermore to examine its expression pattern in preimplantation stage rabbit embryos.

Results

The upstream region of rabbit POU5F1 was subcloned sequenced and four highly conserved promoter regions (CR1-4) were identified. The highest degree of similarity on sequence level was found among the conserved domains between rabbit and human. Among the enhancers the proximal enhancer region (PE-1A) exhibited the highest degree of homology (96.4%). Furthermore, the CR4 regulator domain containing the distal enhancer (DE-2A) was responsible for stem cell-specific expression. Also, BAC library screen revealed the existence of a processed pseudogene of rabbit POU5F1. The results of quantitative real-time PCR experiments showed that POU5F1 mRNA was abundantly present in oocytes and zygotes, but it was gradually reduced until the activation of the embryonic genome, thereafter a continuous increase in POU5F1 mRNA level was observed until blastocyst stage. By using the XYClone laser system the inner cell mass (ICM) and trophoblast portions of embryos were microdissected and examined separately and POU5F1 mRNA was detected in both cell types.

Conclusion

In this study we provide a comparative sequence analysis of the regulatory region of rabbit POU5F1 gene. Our data suggest that the POU5F1 gene is strictly regulated during early mammalian development. We proposed that the well conserved CR4 region containing the DE-2A enhancer is responsible for the highly conserved ESC specific gene expression. Notably, we are the first to report that the rabbit POU5F1 is not restricted to ICM cells only, but it is expressed in trophoblast cells as well. This information may be well applicable to investigate further the possible phylogenetic role and the regulation of POU5F1 gene.

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Scientific Week
2009-08-31 10:29:27

September Training and conference week


  On the 21-25. September, 2009. BioTalentum ltd organize a Scientific Week, connected to its several FP6 and 7 projects. Duirng the event are great authorities will persent about embrionic stem cells and induced pluripotent stem cells.  Read the detailed agenda....

Research Connection Conference 2009
2009-05-13 09:46:22

The conference and exhibition took place in Prague from 7 to 8 May 2009.  Prof. András Dinnyes was an invited speaker in Marie Curie Session. Webcast of the presentations can be seen HERE and HERE.
My Science project exhibited in the conference.
Photos can bee seen in the gallery. HERE.

OTDK triumph
2009-04-21 14:32:25