TGF-BETA-2 GENE AND PROTEIN EXPRESSION IN MATERNAL AND FETAL TISSUES AT VARIOUS STAGES OF MURINE DEVELOPMENT

The transforming growth factor beta family of peptides have diverse ac tions on the reproductive tracts of primates and rodents. In this stud y we report the expression of high levels of mRNA of one member of thi s superfamily, TGF-beta 2, in the pregnant mouse uterus. Using Norther n blot analysis and in situ hybridization techniques, we have examined the pattern of expression of TGF-beta 1, TGF-beta 2 and colony-stimul ating factor (CSF-1) in mouse maternal and fetal tissue at specific da ys of gestation. We report here that TGF-beta 2 is synthesized primari ly in maternal decidual and uterine epithelial tissues. We observed a shift in the major site of synthesis from decidua to uterus between da ys 8.5 and 10.5 of gestation. These data demonstrate that the expressi on of TGF-beta 2 is differentially regulated in the decidua and uterin e epithelial cells at various times during gestation. Small amounts of TGF-beta 2 mRNAs were detected in the fetus, and none was detected in placenta, yolk sac, or amniotic membrane. The uterus is likely the ma jor site of synthesis of the TGF-beta 2 found in mouse amniotic fluid. TGF-beta 1 mRNAs are expressed in the uterus at markedly lower levels when compared to TGF-beta 2 mRNAs in both the decidua and uterus. Our results suggest that there is a,unique regulation of TGF-beta 2 durin g pregnancy which may depend on pregnancy hormone(s) and differentiate s it from the other mammalian isoforms of the TGF-beta s. TGF-beta 2 m ay play an important, albeit unknown, role at the maternal/fetal inter face.