REDR1990 Reproduction in Domestic Ruminants II Maternal Recognition of Pregnancy (5 abstracts)
Departments of Animal Sciences and Biochemistry, University of Missouri, Columbia, MO 65211, USA
Summary. Ovine and bovine trophoblast protein-1 (oTP-1 and bTP-1) have been strongly implicated as antiluteolytic agents and responsible for maternal recognition of pregnancy in sheep and cattle, respectively. Both are interferons (IFN) belonging to the IFN-α family, but their length (172 residues versus 166 for most IFN-α) places them in an unusual subclass (the IFN-αII). The various isoforms of oTP-1 and bTP-1 produced by trophoblast tissue appear to arise in part from translation of multiple mRNAs which are themselves the products of distinct genes. These genes, like those for other IFN-α, are without introns. However, the genes for oTP-1 and bTP-1 form a distinct subgroup within the IFN-αII on the basis of their overall primary sequences and the high conservation of the 3'-untranslated ends of their transcription units. The bTP-1 genes also differ from the bovine IFN-αII in the organization of the promoter regions upstream from the transcription start site. Nevertheless, computer-aided analysis of the primary polypeptide sequences of oTP-1 and bTP-1 indicates that the molecules are likely to have approximately the same shapes and dimensions as all other IFN-α moleculcs. It remains to be determined whether they have unique biological properties which distinguish them from other IFN-α moleculcs.
Keywords: α-interferons; trophoblast; molecular cloning; sheep; cattle
© 1991 Journals of Reproduction & Fertility Ltd