Pregnancy Associated Glycoproteins in Ruminants: Inactive Members of the Aspartic Proteinase Family

Abstract

The Pregnancy Associated Glycoproteins (PAGs) presented in this paper are largely expressed in the ruminant placenta. These proteins are classified as probably inactive members of the aspartic proteinase family. Pepsinogen, renin, cathepsin E & D and chymosine are typical members of this family, characterised by the presence of aspartic acids boarding the recognition sites. Secreted in the peripheral blood of the pregnant female from early pregnancy, these proteins can be used in serological tests for establishing different diagnoses. In the veterinary practice, these diagnoses are useful for both pregnancy confirmation and follow-up of trophoblastic function. The first aspect can help breeders in the management of reproduction, while the second one more specifically concerns clinicians and researchers wishing to establish a differential diagnosis of pathologic conditions affecting pregnancy.

Early pregnancy diagnosis using a commercial ELISA test based on pregnancy-associated glycoproteins in Holstein-Friesian heifers and lactating cows

“…Certain PAGs produced by trophoblastic giant cells on the outer sheet of the placenta pass into the maternal peripheral blood after implantation (8). Antibodies developed against PAGs can be detected by techniques such as radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA) as early as 21 days after insemination, although the most reliable results are obtained after day 27 (9,10).…”

Noninfectious Causes of Pregnancy Loss at the Late Embryonic/Early Fetal Stage in Dairy Cattle

“…The accuracy of the measurement method should also be considered when performing a clinical diagnosis and analyzing data, as results will affect decision making at the time of the initial pregnancy diagnosis. Both early RIA [17] and ELISA tests [18][19][20][21] serve to accurately determine maternal blood concentrations of PAGs and pregnancy-specific protein B (PSPB). These tests are available in laboratories and as on-farm tests and can be used on biological fluids (whole blood, serum, plasma, and milk).…”

Buffalo early pregnancy biomarker coding sequence cloning and partial length expression in E. coli after codon optimization

“…Pregnancy-associated glycoproteins (PAGs) are multi-isoform proteins generated by gene duplication probably due to continuous selection pressure at the maternal-conceptus junction [1]. They are products of mono- and bi-nucleated trophoblast cells, identified in cattle, buffalo, swine, camel, wild deer and bison placenta [2], released extracellular by exocytosis thus available in maternal circulation [3] and used for immunodetection of early pregnancy in ruminants. About 100 PAG genes in bovine [4] and 51 coding PAG transcripts in other ruminant species [5, 6] are reported in the literature.…”