Expression of @entity1192 system mRNA in single blastomeres from XXXX preimplantation embryos.

@entity1 @entity217 @entity1356 @entity10496 @entity1193 @entity1192 @entity52
Gathering knowledge about the molecular events during preimplantation development is one of the most important challenges in @entity52 ( @entity52 ). The @entity1192 ( @entity1192 ) system has been shown to be intimately involved in embryonic implantation. The aim of our study was to detect the major components of the @entity1192 system in single blastomeres from @entity1 preimplantation embryos and to relate our findings to the further development of the biopsied embryos in vitro. Single blastomeres were removed from morphologically normal embryos obtained from dipronuclear zygotes and examined by reverse transcription (RT)-nested polymerase chain reaction (PCR). Expression of @entity217 (external standard), @entity1356 , @entity1193 ( @entity1193 ) and @entity10496 ( @entity10496 ) type I mRNA were related to embryonic development and @entity52 outcome. Blastomeres from 12 embryos were examined: @entity217 and @entity10496 type I mRNA were detected in all blastomeres (100%) whereas @entity1356 could be detected in only nine of the blastomeres (75%). @entity1193 was expressed in only two (17%) of the blastomeres and those were simultaneously positive for @entity1356 . Both @entity1193 positive embryos were arrested in development before reaching blastocyst stage. Five embryos (three of them @entity1356 mRNA positive and two @entity1356 mRNA negative) were transferred as blastocysts; none of the transfers resulted in a pregnancy. We postulate that embryos expressing @entity1193 mRNA in a detectable amount appear more likely to be arrested in early developmental stages.
