NONRADIOACTIVE IN-SITU HYBRIDIZATION OF PORCINE EMBRYOS - A METHOD TODETECT AND LOCALIZE THE EXPRESSION OF EARLY DEVELOPMENTAL GENES

In situ hybridization is a method commonly used for detection and cell ular localization of gene transcription in mammalian embryos. During i mplantation, cells of the blastocyst synthesize paracrine signaling mo lecules in an appropriate manner, via alterations in trophoblast gene expression. We used a digoxigenin-labeled probe for detection of mRNA encoding the embryo isoform of porcine cytochrome P350 aromatase, the terminal enzyme in the estrogen biosynthetic cascade, to localize the cells in which transcription of this gene occurs in late preimplantati on-stage porcine embryos. Trophectodermal cells stained positive, indi cating that transcription of the embryo aromatase isoform-encoding gen e is active in these cells. Similar methods could be used to localize the expression of other early developmental genes in preimplantation p orcine embryos.