Compositions and methods for early pregnancy diagnosis

Abstract

Pregnancy-associated glycoproteins (PAGs) are structurally related to the pepsins, thought to be restricted to the hoofed (ungulate) mammals and characterized by being expressed specifically in the outer epithelial cell layer (chorion/trophectoderm) of the placenta. By cloning expressed genes from ovine and bovine placental cDNA libraries, the inventors estimate that cattle, sheep, and most probably all ruminant Artiodactyla, possess possibly 100 or more PAG genes, many of which are placentally expressed. The PAGs are highly diverse in sequence, with regions of hypervariability confined largely to surface-exposed loops. Selected PAG that are products of the i0nvasive binucleate cells, expressed highly in early pregnancy at the time of trophoblast invasion and expressed weakly, if at all, in late gestation are useful in the early diagnosis of pregnancy. In a preferred embodiment, the invention relates to immunoassays for detecting these PAGs.

1 - 181 . (canceled)  
     
     
         182 . A method for detecting pregnancy in a bovine animal comprising: 
 (a) obtaining a sample from said animal; and    (b) detecting at least one pregnancy associated antigen (PAG) in the sample that is present early in pregnancy and is undetectable at about two months post-partum; whereby detection of the PAG indicates that the animal is pregnant.    
     
     
         183 . The method of  claim 182 , wherein said sample is selected from the group consisting of saliva, serum, blood, milk or urine.  
     
     
         184 . The method of  claim 182 , wherein said detecting comprises ELISA.  
     
     
         185 . The method of  claim 182 , wherein said detecting comprises RIA.  
     
     
         186 . The method of  claim 182 , wherein said detecting comprises Western blot.  
     
     
         187 . The method of  claim 182 , wherein detecting is carried out by immunologic detection.  
     
     
         188 . The method of  claim 187 , wherein immunologic detection comprises detection with polyclonal antisera.  
     
     
         189 . The method of  claim 187 , wherein immunologic detection comprises detection with a monoclonal antibody preparation.  
     
     
         190 . The method of  claim 182 , wherein detecting comprises RNA detection.  
     
     
         191 . The method of  claim 182 , further comprising detecting at least two PAGs in said sample.  
     
     
         192 . The method of  claim 191 , further comprising detecting at least three PAGs in said sample.  
     
     
         193 . The method of  claim 184 , wherein said ELISA is a sandwich ELISA comprising binding the PAG to a first antibody preparation fixed to a substrate and a second antibody preparation labeled with an enzyme.  
     
     
         194 . The method of  claim 193 , wherein said enzyme is alkaline phosphatase or horseradish peroxidase.  
     
     
         195 . The method of  claim 193 , wherein said first antibody preparation is monoclonal.  
     
     
         196 . The method of  claim 193 , wherein said first antibody preparation is polyclonal.