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Endogenous retroviral gene elements (syncytin-Rum1 and BERV-K1), interferon-τ, and pregnancy associated glycoprotein-1 are differentially expressed in maternal and fetal tissues during the first 50 days of gestation in beef heifers - PubMed

  • ️Sun Jan 01 2017

Endogenous retroviral gene elements (syncytin-Rum1 and BERV-K1), interferon-τ, and pregnancy associated glycoprotein-1 are differentially expressed in maternal and fetal tissues during the first 50 days of gestation in beef heifers

K J McLean et al. Transl Anim Sci. 2017.

Abstract

We hypothesized that the endogenous retroviruses [ERV: syncytin-Rum1 and (BERV-K1)], and pregnancy hormones [interferon-τ (IFN-τ), and pregnancy associated glycoprotein-1 (PAG-1)] would be differentially expressed whereas progesterone and insulin concentrations in maternal blood would remain steady during early gestation. To test this hypothesis Angus crossbred heifers (n = 46; ∼15 mo of age; BW = 363 ± 35 kg) were fed native grass hay, supplemented with cracked corn to gain 0.3 kg/d, and given ad libitum access to water. All heifers were subjected to a 5-d CO-Synch + CIDR estrous synchronization protocol and AI (breeding = d 0). Ovariohysterectomies were performed on d 16, 22, 28, 34, 40, and 50 of gestation and at d 16 of the estrous cycle for non-pregnant (NP) controls. Utero-placental tissues [maternal caruncle (CAR); maternal intercaruncular endometrium (ICAR); and fetal membranes, (FM, chorion on d 16, chorioallantois on d 22 to 50)] were collected from the uterine horn ipsilateral to the corpus luteum (CL). Tissues were flash frozen and stored at -80°C. Expression of mRNA was evaluated using qPCR. In CAR, syncytin-Rum1 expression was greater (P < 0.01) on d 50 (81.5-fold) compared with NP controls or any other day of early pregnancy. In contrast, syncytin-Rum1 expression in I-CAR only tended (P = 0.09) to change across days of early pregnancy and did not differ (P = 0.27) in FM tissues. In CAR, the expression of BERV-K1 was not different (P > 0.79) at d 16 and 22, was intermediate at d 28, 34, and 40, and was greatest on d 50 (108-fold increase compared with NP). Expression of BERV-K1 in FM was increased (P < 0.01) on d 28, 34, and 50 compared with NP controls, but at d 40 did not differ from NP controls. The mRNA expression of IFN-τ in FM at d 22 was greater (P < 0.01) than all other days of gestation. In CAR, expression of PAG-1 increased (P < 0.001) dramatically on d 40 (20,000-fold) and d 50 (86,000-fold) compared with NP heifers (P < 0.01). In ICAR, expression of PAG-1 was greater (P < 0.05) on d 28 and 40 (fold increases of 113 and 102, respectively, compared with NP). Insulin concentrations were not different (P = 0.53) but progesterone was greater (P < 0.01) on d 16, 22, 28, 34, and 40 compared with d 50 of gestation. These data confirm differential ERV, IFN-τ, and PAG-1 gene expression during critical time points of early gestation in utero-placental tissues.

Keywords: bovine; early pregnancy; endogenous retroviruses; hormones; maternal recognition.

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Figures

Figure 1.
Figure 1.

Expression of syncytin-Rum1 in reproductive tissues during the establishment of pregnancy in beef heifers: A) syncytin-Rum1 in maternal caruncles (CAR), B) syncytin-Rum1 in uterine endometrium (ICAR), and C) syncytin-Rum1 in fetal membranes (FM). Data presented as a 2-ΔΔCT-fold change normalized to β-Actin and the average of non-pregnant (NP; maternal tissues) or d 22 FM (fetal tissues). Expression pattern line ( – – ) via regression (P < 0.05); regression analysis does not include NP heifers. Means without a common superscript differ (P < 0.05).

Figure 2.
Figure 2.

Expression of bovine endogenous retrovirus-K1 (BERV-K1) in reproductive tissues during the establishment of pregnancy in beef heifers: A) BERV-K1 in maternal caruncles (CAR), B) BERV-K1 in uterine endometrium (ICAR), and C) BERV-K1 in fetal membranes (FM). Data presented as a 2-ΔΔCT-fold change normalized to β-Actin and the average of non-pregnant (NP; maternal tissues) or d 22 FM (fetal tissues). Expression pattern line ( – – ) via regression (P < 0.05); regression analysis does not include NP heifers. Means without a common superscript differ (P < 0.05).

Figure 3.
Figure 3.

Expression of (IFN-τ) in fetal membranes (FM) during the establishment of pregnancy in beef heifers. Data presented as a 2-ΔΔCT-fold change normalized to β-Actin and the average of d 22 FM (fetal tissues). Expression pattern line ( – – ) via regression (P < 0.05); regression analysis does not include NP heifers. Means without a common superscript differ (P < 0.05).

Figure 4.
Figure 4.

Expression of pregnancy associated glycoprotein-1 (PAG-1) in reproductive tissues during the establishment of pregnancy in beef heifers: A) PAG-1 in maternal caruncles (CAR), B) PAG-1 in uterine endometrium (ICAR), and C) PAG-1 in fetal membranes (FM). Data presented as a 2-ΔΔCT-fold change normalized to β-Actin and the average of non-pregnant (NP; maternal tissues) or d 22 FM (fetal tissues). Expression pattern line ( – – ) via regression (P < 0.05); regression analysis does not include NP heifers. Means without a common superscript differ (P < 0.05).

Figure 5.
Figure 5.

Concentrations of hormones in serum of beef heifers during early gestation. A) Concentrations of circulating progesterone in serum of beef heifers B) Concentrations of circulating insulin in serum of beef heifers. Hormones are reported as a pooled mean from heifers (n = 38, 30, 25, 18, 11, and 5 for d 16, 22, 28, 34, 40, and 50; respectively) on each d. Means without a common superscript differ (P < 0.05).

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References

    1. Bassil S., Magritte J. P., Roth J., Nisolle M., Donnez J., Gordts S.. 1995. Uterine vascularity during stimulation and its correlation with implantation in in-vitro fertilization. Hum. Reprod. 10:1497–1501. doi:10.1093/HUMREP/10.6.1497 - PubMed
    1. Bazer F. W. 1992. Mediators of maternal recognition of pregnancy in mammals. Proc. Soc. Exp. Biol. Med. 199:373–384. doi:10.3181/00379727-199-43371A - PubMed
    1. Bazer F. W., Thatcher W. W., Hansen P. J., Mirando M. A., Ott T. L., Plante C.. 1991. Physiological mechanism of pregnancy recognition in ruminants. J. Reprod. Fertil. 43:39–47. - PubMed
    1. Bazer F. W., Ying W., Wang X., Dunlap K. A., Zhou B., Johnson G. A., Wu G.. 2015. The many faces of interferon tau. Invited Review. Amino Acids 47:449–460. doi:10.1007/s00726-014-1905-x - PubMed
    1. Binelli M., Subramaniam P., Diaz T., Johnson G. A., Hansen T. R., Thatcher W. W.. 2001. Bovine interferon-τ stimulates Janus kinase-signal transducer and activator of transcription pathway in bovine endometrial epithelial cells. Biol. Reprod. 64:654–665. doi:10.1095/biolreprod64.2.654 - PubMed

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