TRANSFORMING GROWTH FACTOR-ALPHA AND FACTOR-BETA EXPRESSION IN FERTILIZED AND PARTHENOGENETIC PREIMPLANTATION MOUSE EMBRYOS - RNA DETECTIONWITH FLUORESCENT IN-SITU HYBRIDIZATION

Transforming growth factor (TGF)-alpha and -beta are expressed in pre- implantation embryos and could play an important role in development. Usually gene expression is studied using reverse transcription-polymer ase chain reaction (RT-PCR) but here, we developed a fluorescent in si tu hybridization (FISH) procedure applied on whole embryos that were s pread and fixed on slides after hypotonic shock. This procedure allowe d a rapid and specific detection of mRNA. For the first time, this tec hnique was applied successfully to TGF-alpha, TGF-beta 1 and TGF-beta 2 on parthenogenetic embryos (maternal genome only) and fertilized con trols (maternal and paternal genomes). TGF-beta 1 and beta 2 mRNA both appeared at the late 8-cell stage and increased in morulae and blasto cysts. TGF-alpha expression increased from the 2-cell stage to the bla stocyst stage. Patterns of expression were similar in parthenogenetic and caryogamic embryos, suggesting that no maternal imprinting exists for these three genes.