Time of embryo transport through the mare oviduct

Freeman, D.A.; Weber, J.A.; Geary, R.T.; Woods, G.L.

doi:10.1016/0093-691x(91)90348-h

Cited by 79 publications

(54 citation statements)

References 11 publications

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“…The conceptus arrives into the uterus around 5.5-6.5 days after fertilization (Oguri & Tsutsumi 1972, Betteridge et al 1982, Freeman et al 1991, and in horses and other species, uterine inflammation was found to be harmful to the conceptus and interfere with pregnancy (Adams et al 1987, Reilas et al 2000, Hill & Gilbert 2008. Therefore, it is important that breeding-induced endometritis be resolved before the arrival of the conceptus into the uterus.…”

Section: Introductionmentioning

confidence: 99%

Endometrial inflammatory markers of the early immune response in mares susceptible or resistant to persistent breeding-induced endometritis

Woodward¹,

Christoffersen²,

Campos³

et al. 2013

Reproduction

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Transient endometritis after breeding is necessary for clearance of bacteria and spermatozoa; however, in a subpopulation of mares, the inflammation fails to resolve in a timely fashion. The objective of this study was to describe the uterine inflammatory response in mares susceptible or resistant to persistent breeding-induced endometritis (PBIE) during the first 24 h after induction of uterine inflammation. Twelve mares were classified as susceptible (nZ6) or resistant (nZ6) to PBIE. Mares were inseminated over five estrous cycles and endometrial biopsies were collected at one time point per cycle before (0) and 2, 6, 12, and 24 h after insemination. qPCR analysis for IL1B, IL6, IL8, IFNG, TNF (TNFA), IL10, and IL1RN was performed, and endometrial inflammatory cells were counted for each sample. Relative quantification values reported fold changes in mRNA expression from 0 h values. A general pattern of expression post insemination was observed in both groups of mares. Cytokine mRNA increased at 2 h, peaked between 2 and 12 h, and then decreased. Differences were detected between groups of mares 6 h after challenge; resistant mares had higher mRNA expression of IL6, IL1RN, and IL10 than susceptible mares. Susceptible mares had an increased number of polymorphonuclear neutrophils in the endometrium 2 and 12 h after breeding when compared with resistant mares. These findings describe an inherent difference in the initial immune response to insemination and may help explain the transient nature of inflammation in resistant mares, whereas susceptible mares develop a persistent inflammation.

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Section: Introductionmentioning

confidence: 99%

Endometrial inflammatory markers of the early immune response in mares susceptible or resistant to persistent breeding-induced endometritis

Woodward¹,

Christoffersen²,

Campos³

et al. 2013

Reproduction

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“…First the equine embryo does not exit the oviduct via the prominent uterotubal papilla until as late as 144-156 h after ovulation (Freeman et al 1991). Moreover, unfertilised eggs are not capable of stimulating passage through the ampullary-isthmic junction and are instead retained in the oviduct.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, unfertilised eggs are not capable of stimulating passage through the ampullary-isthmic junction and are instead retained in the oviduct. The stimulus to this selective oviductal transport is the stage-specific production of prostaglandin E 2 by days 4-5 equine conceptuses (Weber et al 1991), and is a clear example of very early embryo-maternal interaction in the horse.…”

Section: Introductionmentioning

confidence: 99%

Influence of the uterine environment on the development of in vitro-produced equine embryos

et al. 2012

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The necessity for early interaction between the embryo and the oviductal and/or uterine environment in the horse is reflected by several striking differences between equine embryos that develop in vivo and those produced in vitro. Better understanding of the salient interactions may help to improve the efficiency of in vitro equine embryo production. In an initial experiment, cleavage-stage in vitro-produced (IVP) equine embryos were transferred into the uterus of recipient mares that had ovulated recently to determine whether premature placement in this in vivo environment would improve subsequent development. In a second experiment, an important element of the uterine environment was mimicked by adding uterocalin, a major component of the endometrial secretions during early pregnancy, to the culture medium. Intrauterine transfer of cleavage-stage IVP equine embryos yielded neither ultrasonographically detectable pregnancies nor day 7 blastocysts, indicating that the uterus is not a suitable environment for precompact morula stage horse embryos. By contrast, exposure to uterocalin during IVP improved capsule formation, although it did not measurably affect the development or expression of a panel of genes known to differ between in vivo and in vitro embryos. Further studies are required to evaluate whether uterocalin serves purely as a carrier protein or more directly promotes improved capsule development.

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“…This acellular membrane forms after the entry of the embryo into the uterus, on late Day 5 after ovulation , Freeman et al 1991. The equine capsule is composed of mucin-like glycoproteins that are produced by the trophoblast and likely modified by the uterine environment; it has great mechanical strength and is extraordinarily resistant to chemical or enzymatic solubilization (Oriol et al 1993a, 1993b, Albihn et al 2003.…”

Section: Introductionmentioning

confidence: 99%

Viability of equine embryos after puncture of the capsule and biopsy for preimplantation genetic diagnosis

Choi¹,

Gustafson-Seabury²,

Velez³

et al. 2010

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The equine embryo possesses a capsule that is considered essential for its survival. We assessed viability after breaching the capsule of early (Day 6) and expanded (Day 7 and 8) equine blastocysts by micromanipulation. The capsule was penetrated using a Piezo drill, and trophoblast biopsy samples were obtained for genetic analysis. Pregnancy rates for Day-6 embryos, which had intact zonae pellucidae at the time of recovery, were 3/3 for those biopsied immediately after recovery and 2/3 for those biopsied after being shipped overnight under warm (w28 8C) conditions. The pregnancy rates for encapsulated Day-7 expanded blastocysts were 5/6 for those biopsied immediately and 5/6 for those biopsied after being shipped overnight warm. Two of four encapsulated Day-8 blastocysts, 790 and 1350 mm in diameter, established normal pregnancies after biopsy. Nine mares were allowed to maintain pregnancy, and they gave birth to nine normal foals. Biopsied cells from eight embryos that produced foals were subjected to whole-genome amplification. Sex was successfully determined from amplified DNA in 8/8 embryos. Identification of disease-causing mutations matched in the analyses of 6/6 samples for the sodium channel, voltage-gated, type IV, alpha subunit (SCN4A) gene and in 6/7 samples for the peptidylprolyl isomerase B (PPIB) gene, in embryo-foal pairs. Thus, the capsule of the equine embryo can be breached without impairing viability. Further work is needed to determine whether this breach is transient or permanent. These findings are relevant to the understanding of equine embryo development and to the establishment of methods for micromanipulation and embryo cryopreservation in this species.

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Time of embryo transport through the mare oviduct

Cited by 79 publications

References 11 publications

Endometrial inflammatory markers of the early immune response in mares susceptible or resistant to persistent breeding-induced endometritis

Endometrial inflammatory markers of the early immune response in mares susceptible or resistant to persistent breeding-induced endometritis

Influence of the uterine environment on the development of in vitro-produced equine embryos

Viability of equine embryos after puncture of the capsule and biopsy for preimplantation genetic diagnosis

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