Detection of pregnancy in sheep by radioimmunoassay of sera for pregnancy-specific protein B

Ruder, C. A.; Stellflug, J. N.; Dahmen, J. J.; Sasser, R.G.

doi:10.1016/0093-691x(88)90227-0

Cited by 63 publications

(23 citation statements)

References 13 publications

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“…In the control ewes immunized against KLH, the biphasic serum profiles of PAGs were quite similar to those obtained by other laboratories (Ruder et al, 1988;Ranilla et al, 1994). The PAG-immunized animals that failed to develop strong reactivity toward PAGs (the 'low-titer' group) exhibited profiles that were essentially identical to the KLHimmunized animals.…”

Section: Discussionsupporting

confidence: 78%

Autoimmunization of ewes against pregnancy-associated glycoproteins does not interfere with the establishment and maintenance of pregnancy

Egen

Ealy²,

Landon³

et al. 2009

Animal

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Pregnancy-associated glycoproteins (PAGs) are a large grouping of placental proteins that belong to the aspartic peptidase gene family. Although useful to detect pregnancy in ruminant species, the function of these molecules is unclear. Several PAGs expressed by trophoblast binucleate cells can enter the maternal circulation, suggesting that they could have a systemic role in altering maternal physiology. The objective of this work was to examine whether these circulating placental antigens were important in pregnancy by actively immunizing ewes against them. PAGs were purified by pepstatin-affinity chromatography and conjugated to the immunogenic protein, keyhole limpet hemocyanin (KLH). Ewes were immunized with PAG-KLH conjugate (n 5 22) or with KLH alone (n 5 9), and bred to intact rams. Blood samples, collected on Day 0 (day of estrus), Day 10, Days 15 to 25 and weekly throughout pregnancy, were analyzed for PAG by an ELISA. On Day 30, pregnancy was confirmed by ultrasound. Ewes immunized against PAG-KLH produced a range of reactive anti-PAG titers, whereas all immunized ewes had high anti-KLH immunoreactivity. PAGs became detectable in the anti-KLH (control) ewes at Day 21.6 6 2.2 of pregnancy. Those ewes immunized against PAGs (n 5 7), that had very low immunoreactivity toward PAGs, had measurable PAG by Day 22.9 6 1.3, and their PAG serum profiles throughout pregnancy did not differ from the controls. Those exhibiting moderate to high anti-PAG immunoreactivity (n 5 15), had significantly lower PAG concentrations than controls, with antigen not becoming detectable until Day 48.1 6 15.6. The decrease in circulating PAG in the immunized animals did not correlate with changes in pregnancy rates, lamb number or lamb birth weight. These results suggest that while PAGs may play a role in maintaining pregnancy, their major contribution is likely to be at the fetal-maternal interface. Their actions at extra-placental sites are presumably of more secondary importance.

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Section: Discussionsupporting

confidence: 78%

Autoimmunization of ewes against pregnancy-associated glycoproteins does not interfere with the establishment and maintenance of pregnancy

Egen

Ealy²,

Landon³

et al. 2009

Animal

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“…The presence of PAGs can be measured by radioimmunologic (RIA) and immunoenzymatic (ELISA) tests. These PAG tests allow for early pregnancy diagnoses in domestic cattle [69,80,91,[95][96][97][98], sheep [70,[99][100][101][102][103][104] and goats [105,106]. Moreover, heterologous PAG tests were also useful for pregnancy diagnoses in wild ruminants, i.e.…”

Section: Pregnancy Diagnostic Pag Testsmentioning

confidence: 99%

Biodiversity of multiple Pregnancy-Associated Glycoprotein (PAG) family: gene cloning and chorionic protein purification in domestic and wild eutherians (Placentalia) – a review

2006

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-This review presents a broad overview of chorionic glycoproteins encoded by the Pregnancy-Associated Glycoprotein (PAG) gene family and also serves to illustrate how the recent discovery of the PAG family has contributed to our general knowledge of genome evolution, placental transcription and placental protein expression. The complex and large PAG family is restricted to the Artiodactyla order, although single PAG-like genes have also been identified in species outside the Artiodactyla. The PAGs are members of the aspartic proteinase (AP) superfamily. Unexpectedly, however, some members of the PAG family possess amino acid substitutions within and around the active site that likely render them unable to act as proteinases. This paper summarises the available information regarding biodiversity of PAG gene expression based on cDNA cloning, mRNA localisation studies and the structural organisation of the PAG genes with a particular emphasis on PAG promoters. It also compares available data regarding PAG protein purifications, sequencing and their N-glycodiversity. Finally, it discusses the scientific relevance, possible functional roles of the PAGs and describes possible profitable applications related to the detection of PAG proteins in the blood of pregnant domestic and wild species. chorionic glycoproteins / eutherian PAG family / diagnostic PAG markers

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“…Although the RIA test for the measurements of bovine PSPB accurately detects pregnancy (100%) and non-pregnancy (83%) in sheep from Days 26 to 106 of gestation (Table 4), ovine PSPB concentration cannot be measured quantitatively because ovine antigen cross-reacts only incompletely with antibodies to bPSPB (Ruder et al 1988 Willard et al (1987) developed a quantitative RIA test for the measurements of ovine pregnancy specific protein B (oPSPB). oPSPB became detectable at 19.7 ± 0.1 (Mean ± SE) (Willard et al 1987;1995) and 21.7 ± 0.6 days postmating (Wallace et al 1997).…”

Section: Assessment Of Pregnancy Proteins 41 Pregnancy-specific Promentioning

confidence: 99%

Pregnancy Dagnosis in Sheep: Review of the Most Practical Methods

Karen¹,

Kovács²,

Beckers³

et al. 2001

Acta Vet. Brno

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Various practical methods have been used for pregnancy diagnosis in sheep. Both pregnancy and fetal numbers are accurately diagnosed by using radiography after day 70 of gestation. Rectal abdominal technique detects pregnancy with an accuracy of 66 to 100% from d 49 to 109 of gestation, however, it has a low (17 to 57%) accuracy for determining multiple fetuses. Progesterone assays have a high sensitivity (88% to 100%) and a low specificity (60% to 72%) at d 16 to 18. Estrone sulphate assay accurately detects pregnant ewe at d 30 to 35. Ovine pregnancy specific protein B (PSPB) assay accurately (100%) detects pregnancy from d 26 after breeding onwards. The accuracy of progesterone, estrone sulphate and oPSPB assays for determining fetal numbers is relatively low. A-mode and Doppler ultrasonic techniques accurately detect pregnancy during the second half of gestation. Fetal numbers cannot be determined by A-mode ultrasound, while the Doppler technique needs experience to achieve high accuracy. Transrectal B-mode, real time ultrasonography identifies the embryonic vesicles as early as d 12.8 after mating, but the sensitivity of the technique for pregnancy is very low (12%) earlier than 25 d after mating. Transabdominal B-mode ultrasonography achieved high accuracy for pregnancy diagnosis (94% to 100%) and the determination of fetal numbers (92% to 99%) on d 29 to 106 of gestation. Realtime, B-mode ultrasonography appears to be the most practical and accurate method for diagnosing pregnancy and determining fetal numbers in sheep.

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Detection of pregnancy in sheep by radioimmunoassay of sera for pregnancy-specific protein B

Cited by 63 publications

References 13 publications

Autoimmunization of ewes against pregnancy-associated glycoproteins does not interfere with the establishment and maintenance of pregnancy

Autoimmunization of ewes against pregnancy-associated glycoproteins does not interfere with the establishment and maintenance of pregnancy

Biodiversity of multiple Pregnancy-Associated Glycoprotein (PAG) family: gene cloning and chorionic protein purification in domestic and wild eutherians (Placentalia) – a review

Pregnancy Dagnosis in Sheep: Review of the Most Practical Methods

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