|Matteri, Robert - Bob|
Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract only
Publication Acceptance Date: 7/31/1999
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Successful pregnancy requires multiple interactions between the conceptus and the mother. Pregnancy-associated glycoproteins (PAG), members of the aspartic proteinase gene family, may participate in these interactions. A fragment of PAG 2 has been identified as early as d 11 in pig embryos. In contrast, there are no reports on the expression of PAG 1 and 2 genes in normal or parthenogenetic expanded blastocysts. The objective of this study was to determine whether PAG genes are expressed in expanded blastocysts. Day 7 expanded blastocysts produced in vitro or via electric activation of oocytes were analyzed by RT-PCR for the presence of mRNA specific for PAG1 and 2. Zonae pellucidae-free blastocysts were lysed by freezing-thawing and the whole lysate was used for RT-PCR. RT was performed on 30 embryos, and PCR was conducted on 10 embryo equivalents for PAG1 and 2, and 5 embryo equivalents for beta-actin as an internal control. .As a negative control, in vitro-derived embryos were subjected to RT without RTase prior to PCR to examine whether the products were derived from genomic DNA or contamination. PCR products were analyzed by electrophoresis on agarose gels and subjected to Southern blotting with nonradioactive probes. Southern blot analysis revealed the presence of mRNA encoding PAG1 and 2 in fertilized and parthenogenetic blastocysts. Partial sequencing of PAG1 and 2 in in vitro-derived blastocysts showed that they shared 99% and 100% identity, respectively, to porcine PAG genes identified in pig trophoblast at d 15. This study indicates that PAG1 and 2 genes are expressed as early as d 7 in expanded blastocysts and that these genes are not maternally imprinted.