Pregnancy-associated glycoproteins (PAG) as pregnancy markers in the ruminants (original) (raw)
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Theriogenology, 2003
Pregnancy-associated glycoproteins (PAGs) are antigens synthesized in the super®cial layers of the ruminant trophoblast. Initially, they were identi®ed either as proteins released into the maternal bloodstream (where they have applications in pregnancy diagnosis) (PAG1) or as molecules binding to the LH receptor (PAG2). In this study, double radial immunodiffusion was used to test the ability of antisera raised against different PAG molecules (bovine, ovine and caprine) to react with placental extracts from nonruminants (rabbit, cat, mouse, pig, and wild pig) and ruminants (cow, ewe, and goat). Placental extracts from all nonruminants tested except rabbit reacted with anti bovine PAG2 (anti-boPAG2). Extracts of ruminant placentas reacted with different antisera, con®rming the expression of various PAG molecules. According to the time at which the placentas were collected (early or middle pregnancy), the reaction differed as regards the thickness, position, and number of precipitation lines, suggesting that PAG expression varies as pregnancy progresses. Bos indicus and Bos taurus placental extracts exhibited different reactions with anti-boPAG2: a single precipitation line in the former case and two lines in the latter. This suggests differential expression of boPAG2 related glycoproteins in these two subspecies.
2007
Pregnancy diagnosis is an important part in reproduction management of ruminants. In the last years, a large polymorphic family of placenta-expressed proteins has been discovered in ruminant species and used for pregnancy diagnosis. Members of this family are named pregnancy-associated glycoproteins (PAG), being synthesized in the mono-and binucleate cells of the ruminant's trophectoderm. Part of them are released in the maternal blood circulation where they can be assayed by different laboratory techniques. Due to large variety of expressed molecules and to large variations in the post-translational processing of the PAG, different immuno-systems present different ability to quantify the PAG released in blood. The sensitivity (92 to 100%) and specificity of PAG radioimmunoassay when used for pregnancy diagnosis are very high. The assay of PAG can also bring very interesting information for researchers working in programs focused on the study of embryonic and fetal mortalities, as well as on embryo biotechnology (ET, FIV, clonage), animal nutrition, or infections diseases resulting in pathologies affecting the pregnancy.
Research in Veterinary Science, 2009
The measurement of serum or plasma PAG concentrations is currently used as a specific method for pregnancy diagnosis in cattle. In this study, the correlation between five radioimmunoassay systems (RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool) developed for measurement of PAG concentrations in ruminant species was investigated in plasma from pregnant Friesian Holstein females. Plasma PAG concentrations (ng/mL) measured by different RIA systems were significantly correlated between them (P 0.81; P < 0.001). PAG concentrations increased significantly from Day 21 (n = 27) to 30 (n = 37) after AI by use of all PAG-RIA systems. From Day 30 to 80 after AI, lower PAG concentrations were observed when using the homologous system RIA-497. The addition of several proteinase inhibitors changed neither the non specific binding nor the B 0 binding to the tracer. Our results suggest that all tested PAG-RIA (RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool) are highly correlated and can be useful to follow PAG concentrations in samples collected during the first trimester of gestation.
Reproductive biology, 2005
Characterization of the Pregnancy-Associated Glycoproteins (PAG) is important for studies of reproduction of various eutherian domestic, wild and endangered mammals. Distinct chorionic PAG genes are expressed in embryo-origin cells: pre-placental trophoblast (TR) and in placental trophectoderm (TRD) of various entherians. This study demonstrates in vitro production of the PAG proteins during long-term cultures of various chorionic explants: porcine TR or TRD, cotyledonary (CT) of European bison (Eb), and CT or intercotyledonary (intCT)-TRD of the cattle. Chorionic proteins isolated from media were analyzed by homologous or heterologous Western immunoblotting with anti-PAG sera, raised against cellular bovine or secretory porcine antigens. Used anti-PAG sera identified diverse molecular forms of released PAG proteins: 43-69 kDa for EbPAG proteins, 40-85 kDa for bovine PAG (bPAG), and 43-73 kDa for porcine PAG (pPAG). Immunoblotting revealed also that both CT and intCT-TRD explants se...
Pregnancy – associated glycoproteins as a new diagnostic tool in cattle reproduction
Schweizer Archiv für Tierheilkunde, 2009
Pregnancy-associated glycoproteins as a new diagnostic tool in cattle reproduction Abstract Pregnancy-associated glycoproteins are powerful pregnancy markers in domestic cattle. These proteins are expressed in mono-and binucleate trophoblast cells from the first days of gestation until calving. Different molecules were identified as being expressed at various stages of pregnancy. However, up to date, their functions and activities during pregnancy have not yet been established. Specific RIA tests were developed (classic and alternative RIA) and used to measure the concentration of these glycoproteins in blood during gestation and the postpartum period in cattle. In maternal blood, PAGs rise to detectable levels from days 24 to 28 after fertilization. A recent study indicated that PAGs can also be detected in milk samples. However, concentrations in milk are much lower when compared to those of plasma.
Theriogenology, 2003
The aim of the present work was undertaken to describe three cases of the bPAG concentration measure by three RIA systems during the post-partum period in non-pregnantcow. Three Holstein-Friesian cows of mixed age and parity were diagnosed as non-pregnant. Blood samples were removed from the coccygeal vessel into EDTA-coated tubes. Samples were collected every 2 days during a stabling period of two months in the absence of males. Plasma was obtained by centrifugation immediately after collection and was stored at-20 °C until assay. Plasmatic PAG concentration was measured by radioimmunoassay technique with some modifications. In RIA-780 and RIA-809, there were high peak of PAG concentration that reached 2.56 ng/ml and 0.89 ng/ml, respectively. These peaks lasted longer than 3 days (two successive samples were positive). The other RIA systems gave the values of PAG concentrations below cutoff of pregnancy diagnosis (> 0.8 ng/ml) and remains always non-pregnant. Our data shows clearly that there is another source of glycoproteins expression (e.g. ovarian) apart from the placenta in cow. The present study could be a field for future larger studies on the same subject by exploring deeply other extra structures placental.
2014
The aim of the present study was to investigate the use of a PAGs ELISA-Sandwich kit (Ref. code E.G.7. CER. Marloie, Belgium) for both early pregnancy diagnosis (in Sardi sheep) and the pregnancy follow up (in Boujaâd and Boujaâd x D’man sheep). In Sardi breed, plasma samples were obtained from pregnant ewes (n = 17) from day 18 to 30 of gestation at 2 days interval. In Boujaâd (n = 8) and Boujaâd x D’man (n = 20) the blood samples were weekly collected from the first week of gestation till the 4th week after lambing. The PAG concentrations were determined by a sandwich-ELISA based on purified bovine PAG (boPAG-67 kDa) as a standard, the antiserum raised against caprine PAG (caPAG-55+62 kDa) as a capture antibody (1/40 000) and antiserum raised against purified PAG from buffalo (AS 859) as detection antibody (1/32 000). The Avidin-HRP and TMB were used to reveal reactions. Ewes were assumed to be pregnant when PAG concentrations were higher than 0.8 ng/ml. Results showed that in Sar...
Animals
This study was carried out to determine ovine pregnancy-associated glycoprotein (oPAG) levels in the plasma of Sarda and Lacaune ewes throughout gestation and in the first month postpartum, using two heterologous radioimmunoassays (RIA-706 and RIA-srPool) and to study the correlations between PAG levels and fetal gender and number. On Day 18 of pregnancy, PAG concentrations were detected in 90.1% and 80.8% of Sarda pregnant ewes with RIA-706 and RIA-srPool, respectively; and in 90% and in 75% of Lacaune pregnant ewes with RIA-706 and RIA-srPool, respectively. From Day 30, PAG concentrations were detected in all pregnant ewes by using both RIA methods. In the postpartum period, the PAG concentrations in Sarda ewes decreased rapidly reaching minimal levels (<1 ng/mL) on day 28 using both RIA-706 and RIA-srPool. In Lacaune ewes, PAG-706 levels were higher than PAG-srPool from parturition until the last day of observation (Day 28 postpartum). It was also observed that mean concentrat...
Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 2008
Pregnancy diagnosis is an important part in reproduction management of ruminants. The aim of the study was to use a new method for evaluating the bPAG and cPAG in milk and blood bPAG and compare this results with the other method for pregnancy diagnosis in the cows. The study was carried out in 220 Holstein Frisian cows. Heparinised blood samples were taken from the jugular vein and stored at -20 degrees C until PAG assay by RIA. For bPAG and cPAG, RIA test, milk samples were homogenized. Pure bPAG was used as a standard tracer described by Zoli et al. (1992). The cows were diagnosed as pregnant by means of USG (Aloka SSD 210) and by rectal palpation. bPAG and cPAG concentration in milk increased after 28 day of pregnancy and showed the rapid increase near the parturition. The same results of bPAG concentration we obtained in the blood samples. The decline of bPAG concentration was faster in the milk than in the blood. The data showed that the RIA method is precise enough to measure...
Measurement of Ovine Pregnancy-Associated Glycoprotein (PAG) During Early Pregnancy in Lacaune Sheep
Reproduction in Domestic Animals, 2007
This study describes ovine pregnancy-associated glycoprotein (ovPAG) concentrations in 20 Lacaune sheep during early pregnancy. Measurements were performed by using semipurified ovPAG as standard, tracer and immunogens for antibody production in rabbits. Antisera R780 (against ovPAG 57+59kDa ) and R805 (against ovPAG5 58+61kDa ) were used respectively in RIA-780 and RIA-805. Blood samples were collected at days 0, 18, 20, 22 and 25 after artificial insemination. From day 18 after breeding onward, the mean ovPAG concentration was significantly higher (p < 0.001) in plasma samples from pregnant ewes (n ¼ 17) than in nonpregnant ones (n ¼ 3). The specific activity of the tracer was 11 760 Ci/mmol in RIA-780 and 14 900 Ci/mmol in RIA-805. The minimal detection limits for RIA-780 and RIA-805 were 0.2 ng/ml and 0.3 ng/ml, respectively. The intra-assay CV of samples with low (1.0 ng/ml), medium (2.5 ng/ml) and high (4.0 ng/ml) PAG concentrations were 3%, 6% and 9% for RIA-780 and 8%, 9% and 5% for RIA-805. The inter-assay CV in the same samples were 13%, 12% and 7% for RIA-780 and 13%, 11% and 5% for RIA-805. The recovery was higher than 95% in both assays. No cross-reaction was observed with members of aspartic proteinase family as well as with other tested proteins. In both RIA-780 and RIA-805, inhibition of the binding of the tracer by antisera was parallel between standard curve and serial dilutions of pregnant ewe samples. In conclusion, the two homologous RIA systems are suitable for early quantification of ovPAG concentrations in ewe plasma samples from day 18 after breeding.