Transferrin gene expression in maternal liver, fetal liver and placenta during pregnancy in the mouse.

Two clones that are homologous to the mouse liver transferrin gene were isolated from a differential screen performed on a mouse cDNA library constructed from placenta. Using an insert derived from the larger of these clones as a template for the generation of random primed cDNA probes, northern blots were conducted against total RNA collected sequentially from placenta (7 days before birth to birth), maternal liver (7 days before birth to birth) and fetal liver (5 days before birth to birth). An approximately 2.3 kb message was detected in all three tissues which was upregulated in late gestation. Message was very abundant in both maternal and fetal liver, and present, but weak, in placenta. The clones were partially sequenced and both clones contain sequence that is identical to mouse liver transferrin. The data presented demonstrate an increase in mRNA transferrin in late gestation in maternal and fetal liver. Additionally, the placenta expresses a gene homologous to liver transferrin and it also is upregulated in late gestation.