Comparative aspects of implantation

Bazer, Fuller W.; Spencer, Thomas E.; Johnson, Greg A.; Burghardt, Robert C.; Wu, Guoyao

doi:10.1530/rep-09-0158

Cited by 345 publications

(305 citation statements)

References 112 publications

(118 reference statements)

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“…Around days 10 and 14 of pregnancy, embryos elongate and start to attach to the uterine wall. Further developed embryos will elongate quicker and get a larger implantation site (reviewed by Bazer et al 2009), which will provide an increased placental surface area (Stroband and Van der Lende, 1990). Foxcroft et al (2000) showed that substantial embryonic losses occur between day 26 and 44 of pregnancy.…”

mentioning

confidence: 99%

Relationships between ovulation rate and embryonic and placental characteristics in multiparous sows at 35 days of pregnancy

Silva

Brand

Laurenssen

et al. 2016

Animal

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The objective of this study was to investigate relationships between ovulation rate (OR) and embryonic and placental development in sows. Topigs Norsvin ® sows (n = 91, parity 2 to 17) from three different genetic backgrounds were slaughtered at 35 days of pregnancy and the reproductive tract was collected. The corpora lutea (CL) were counted and the number of vital and non-vital embryos, embryonic spacing (distance between two embryos), implantation length, placental length, placental weight and embryonic weight were assessed. The difference between number of CL and total number of embryos was considered as early embryonic mortality. The number of non-vital embryos was considered as late mortality. Relationships between OR and all other variables were investigated using two models: the first considered parity as class effect (n = 91) and the second used a subset of sows with parities 4 to 10 (n = 47) to analyse the genetic background as class effect. OR was significantly affected by parity ( P < 0.0001), but was not affected by the genetic background of the sows. Parity and genetic background did not affect embryonic and placental characteristics at 35 days of pregnancy. OR (varying from 17 to 38 CL) was positively related with early embryonic mortality (β = 0.49 ± 0.1 n/ovulations, P < 0.0001), with late embryonic mortality or number of non-vital embryos (β = 0.24 ± 0.1 n/ovulations, P = 0.001) and with the number of vital embryos (β = 0.26 ± 0.1 n/ovulations, P = 0.01). However, dividing OR in four classes, showed that the number of vital embryos was lowest in OR class 1 (17 to 21 CL), but not different for the other OR classes, suggesting a plateau for number of vital embryos for OR above 22. There was a negative linear relationship between OR and vital embryonic spacing (β = −0.45 ± 0.1 cm/ovulation, P = 0.001), implantation length (β = −0.35 ± 0.1 cm/ovulation, P = 0.003), placental length (β = −0.38 ± 0.2 cm/ovulation, P = 0.05) and empty space around embryonic-placental unit (β = −0.4 ± 0.2 cm/ovulation, P = 0.02), indicating uterine crowding. Further analyses showed that effects of OR on embryonic and uterine parameters were related with the increase in late mortality and not early embryonic mortality. Therefore, we conclude that a high OR results in an moderate increase in the number of vital embryos at day 35 of pregnancy, but compromises development in the surviving embryonic/placental units, suggesting that the future growth and survival of the embryos might be further compromised.

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Relationships between ovulation rate and embryonic and placental characteristics in multiparous sows at 35 days of pregnancy

Silva

Brand

Laurenssen

et al. 2016

Animal

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“…Like other ungulates (Perisodactyla and Artiodactyla), ruminant conceptuses remain freefloating after hatching from the zona pellucida (day 8-10 of pregnancy in cattle). Intimate contact with the uterus does not occur until on or after day 16 of pregnancy in cattle (Bazer et al 2009). This requires the development of a very different pregnancy signal, one that can function locally within the uterus instead of systemically.…”

Section: Interferons At the Placental-maternal Interfacementioning

confidence: 99%

The evolution of interferon-tau

Ealy¹,

Wooldridge²

2017

Reproduction

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Thirty years ago, a novel type I interferon (IFN) was identified by molecular cloning of cDNA libraries constructed from RNA extracted from ovine and bovine pre-implantation embryos. This protein was eventually designated as IFN-tau (IFNT) to highlight its trophoblast-dependent expression. IFNT function is not immune related. Instead, it interacts with the maternal system to initiate the establishment and maintenance of pregnancy. This activity is indispensable for the continuation of pregnancy. Our review will describe how IFNT evolved from other type I IFNs to function in this new capacity. IFNT genes have only been identified in pecoran ruminants within the Artiodactyla order (e.g. cattle, sheep, goats, deer, antelope, giraffe). The ancestral IFNT gene emerged approximately 36 million years ago most likely from rearrangement and/or insertion events that combined an ancestral IFN-omega (IFNW) gene with a trophoblast-specifying promoter/enhancer. Since then, IFNT genes have duplicated, likely through conversion events, and mutations have allowed them to adapt to their new function in concert with the emergence of different species. Multiple IFNT polymorphisms have been identified in cattle, sheep and goats. These genes and gene alleles encode proteins that do not display identical antiviral, antiproliferative and antiluteolytic activities. The need for multiple IFNT genes, numerous alleles and distinct activities remains debatable, but the consensus is that this complexity in IFNT expression and biological activity must be needed to provide the best opportunity for pregnancy to be recognized by the maternal system so that gestation may continue. Reproduction (2017) 154 F1-F10

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“…In contrast to what occurs in primates and mice, in cattle, embryo implantation and placentation do not take place immediately after fertilisation; instead, the conceptus spends an extended period of time in the uterine lumen before fixing itself to the endometrium (BAZER et al, 2009). …”

Section: Introductionmentioning

confidence: 97%

Administration of GnRH on the day of fixed-time artificial insemination (FTAI) and melengestrol acetate (MGA) administration after ftai in non-suckling nelore cattle

Silva¹,

Leão²,

Rodrigues³

et al. 2015

Sem. Ci. Agr.

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The present study evaluated the effect of administering buserelin acetate (GnRH) at the time of fixedtime artificial insemination (FTAI), along with the effect of oral administration of melengestrol acetate (MGA) after FTAI on conception rates in non-suckling Nelore cattle. In Experiment I, the effect of GnRH application at the time of FTAI was evaluated, as was administration of MGA from the 13 th through the 18 th day following FTAI (D24 to D29 after the initiation of the FTAI protocol). Experiment I was performed in 215 non-suckling cattle of the Nelore breed, divided into four experimental groups: Control group: 56 cows subjected to FTAI without GnRH injection; GnRH group: 51 cows subjected to GnRH at the time of FTAI; MGA Group: 57 cows subjected to FTAI without the application of GnRH with mineral supplementation and the addition of 2.28 g of MGA ® Premix per cow per day from D24 to D29 after the initiation of the FTAI protocol; MGA and GnRH group: 51 cows subjected to GnRH injection at the time of FTAI, with mineral supplementation and the addition of 2.28 g of MGA ® Premix per cow per day from D24 to D29 after the initiation of the FTAI protocol. In Experiment II, the effect of providing MGA five to ten days after FTAI was evaluated in 196 non-suckling pluriparous Nelore cows, divided into two groups: Control group: 104 cows subjected to FTAI, not supplemented with MGA; treated group: 92 cows supplemented with the addition of 2.28 g of MGA ® Premix per cow per day from D15 to D20 after the initiation of the FTAI protocol. Diagnosis of gestation was carried out 45 days after FTAI. Both experiments were conducted using a completely randomised design and analysed via the SAS MIXED procedure. In Experiment I, the control group displayed a lower conception rate (32.1%) compared with the groups administered GnRH, MGA, and both MGA and GnRH, which were respectively provided with MGA after FTAI (45.6%), GnRH at the time of FTAI (50.9%), and the combination of the two treatments (50.9%) (P<0.05). In Experiment II, the control group displayed a higher conception rate (40.38%) compared with the group receiving MGA post-FTAI (18.48%) (P<0.05). It was concluded that the injection of buserelin acetate (GnRH) at the time of FTAI and the oral administration of MGA ® Premix from the 13 th to the 18 th day after FTAI increased the conception rates in non-suckling Nelore cattle. However, when MGA ® Premix was administered orally from the fifth to tenth day post-FTAI, conception rates in non-suckling Nelore cattle were reduced.

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Comparative aspects of implantation

Cited by 345 publications

References 112 publications

Relationships between ovulation rate and embryonic and placental characteristics in multiparous sows at 35 days of pregnancy

Relationships between ovulation rate and embryonic and placental characteristics in multiparous sows at 35 days of pregnancy

The evolution of interferon-tau

Administration of GnRH on the day of fixed-time artificial insemination (FTAI) and melengestrol acetate (MGA) administration after ftai in non-suckling nelore cattle

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