EXPRESSION PROFILE OF TRANSFORMING GROWTH FACTOR BETA (TGF-B) MEMBERS IN THE RAT OVIDUCT

PABLO A. VALDECANTOS; CONSTANAZA M. LOPEZ; MARTIN E. ARGAÑARAZ; DORA C. MICELI

Capital Federal, Buenos Aires, Argentina

Jornada; I Jornadas Internacionales del Instituto de Investigacion y Tecnologia en Reproduccion Animal.; 2008

Instituto de Investigacion y Tecnologia en Reproduccion Animal

The mammalian oviduct provides an appropriate environment for fertilization and early embryonic development synthesizing and releasing molecules into the lumen. Active cell divisions, the embryonic genome activation and the reprogramming of the embryo gene expression take place after a few cleavage divisions in the oviduct. During this preimplantation period, the oviduct creates a microenvironment that serves to facilitate the optimal early embryo development, in part by the secretion of cytokines and growth factors that are known to be important for the survival of very early embryos. Members of the superfamily of the Transforming Growth Factor beta (TGF-b) and their receptors have been detected in the mammalian oviduct. In this work, we use the reverse transcription polymerase chain reaction (RT-PCR) to study the expression pattern of the TGF-b/activin subfamily (TGF-b1, TGF-b2, TGF-b3, Inhibin a, Inhibin ba, Inhibin bb, Inhibin bc, Lefty1, Lefty2 and Nodal) and some members of the BMP/GDF subfamily (Bmp2, Bmp7, Bmp10, Bmp15, Gdf9 and Gdf10) in the rat oviduct during normal sexual cycle and early pregnancy. Oviducts from normal sexual cycling (proestrus, diestrus and estrus) and early pregnant rats (day 1 to 6 after mating) were used. Total RNA samples for cDNA synthesis were isolated with TriReagent (MRC) and reverse transcribed using oligo dT and M-MLV reverse transcriptase. Primers sequences for each mRNA were designed according to the nucleotide sequences obtained from the rat genome database. Transcripts for all of the members studied, except Inhibin bc, were detected in rat oviducts. As compared to the constitutively expressed b-actin mRNA, Bmp7 mRNA was the more abundant; lowest mRNA levels were found for Nodal, Bmp10, Lefty1 and Inhibin a. Significant changes in the expression profile of Inhibin ba, Lefty1, Lefty2 and Gdf9 were observed during the estrous cycle; increasing levels from day 1 to 6 of early pregnancy were also observed for Inhibin ba and Bmp10 mRNAs. To the best of our knowledge, this is the first time Lefty1, Nodal, Bmp1, Bmp7, Bmp10 and Gdf10 genes are reported as being expressed in the mammalian oviduct. Our results indicate that the rat oviduct express a complex combination of TGF-bs; proteins codified by these mRNAs may influence fertilization, early embryonic development or oviduct remodeling.