The anatomy and physiology of pre-attachment bovine embryos

Betteridge, K.; Fléchon, J.‐E.

doi:10.1016/0093-691x(88)90038-6

Cited by 227 publications

(190 citation statements)

References 120 publications

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“…These observations are similar to that of normal bovine blastocysts developed in vivo (Betteridge and F16chon, 1988). The presence of apical junctional complexes (tight junctions, adherent junctions and desmosomes) between adjacent trophoblast cells is also characteristic of the blastocysts of a large number of mammalian species (Enders, 1971) and is a necessary condition for the establishment of the blastocoele cavity (review by F16chon and Guillomot, 1992).…”

Section: Discussionsupporting

confidence: 63%

Cellular evaluation of bovine nuclear transfer embryos developed in vitro

Heyman¹,

Degrolard²,

Adenot³

et al. 1995

Reprod. Nutr. Dev.

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Section: Discussionsupporting

confidence: 63%

Cellular evaluation of bovine nuclear transfer embryos developed in vitro

Heyman¹,

Degrolard²,

Adenot³

et al. 1995

Reprod. Nutr. Dev.

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“…Similarly, although my results confirmed the hypothesis that EB performed at Day 7 post-oestrus will not affect the CL lifespan, CL functionality is impaired throughout the oestrous cycle due to the lower level of P4 found in heifers biopsied at Day 7 post-oestrus compared to heifers biopsied at Day 4 post-oestrus. Since the role of P4 during the second week of gestation is to regulate embryo elongation (Betteridge and Fléchon, 1988) and it is also required for a successful maternal recognition of pregnancy, reduction of P 4 output from the CL results in changes to the endometrial transcriptome which in turn is responsible for a delay in conceptus elongation (Clemente et al, 2009, Forde et al, 2012. In conclusion, this Model could be the most accurate and indicative of endometrial receptivity but embryo survival may be highly compromised.…”

Section: Discussionmentioning

confidence: 98%

“…After the embryo enters the uterus, 4 to 6 days after fertilisation (Betteridge and Fléchon, 1988) a coordinated dialogue between the embryo and the endometrium starts. The endometrial-conceptus interaction is necessary to prepare the endometrium to support embryo development, elongation, maternal recognition of pregnancy and establish a successful attachment and ongoing pregnancy (Bazer et al, 2012).…”

Section: Role Of Progesterone On Embryo Development and Survivalmentioning

confidence: 99%

63 Effect of Endometrial Biopsy on Uterine Health of Tropically Adapted Beef Cattle

Ramirez-Garzon

Satake

Lyons

et al. 2017

Reprod. Fertil. Dev.

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In cattle, early embryonic loss during the first two to three weeks after fertilisation is recognised as the major cause of reproductive failure, with consequent significant impacts on business performance of beef and dairy farms. Inadequate endometrial receptivity is considered an important cause of early embryonic mortality in cattle. A pilot experiment was conducted to compare the outcome of performing different endometrial sampling procedures in tropically adapted (Bos indicus x Bos taurus) heifers, and to select the most suitable method to collect samples for investigation of endometrial gene expression. Endometrial biopsy (EB) using a biopsy device with a diameter similar to an artificial insemination gun (10366L Karl Storz®, Germany) was found to be the most reliable method of collecting endometrial samples in these heifers, with the samples recovered yielding a mean concentration of RNA of 72.9 ±39.3 ng/µl and mean RNA integrity number (RIN) of 7.3 ±1.1.To assess the likely safety of conducting EB in cattle a systematic review of published information assessing the impact of EB on subsequent pregnancy rates was conducted. Using the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) protocol, online searches identified 1164 possible studies. After applying the exclusion criteria, six studies allowed the comparison of pregnancy rates between sampled (n= 1,208) and non-sampled cows (n=2,393). The results showed that EB can be performed before breeding without adversely affecting the likelihood of cows becoming pregnant.A major objective of the research was to determine whether EB and evaluation of endometrial gene expression could be used to identify tropically adapted embryo transfer (ET) recipients more likely to become pregnant. Three potential EB scenarios were investigated, 1) EB on Day 7 of the oestrous cycle prior to the cycle when ET would be performed, 2) EB on Day 4 of the oestrous cycle in which ET would be performed i.e. EB 3 days before ET, and 3) EB on the same day when ET would be performed.The first study assessed the morphological and inflammatory changes induced by endometrial biopsy. Pre-synchronised heifers underwent EB from the horn ipsilateral to the corpus luteum (CL) either at Day 7 of the previous cycle (Group 1 n=10) followed by administration of a luteolytic dose of prostaglandin F2α or at Day 4 (Group 2, n=7) of the present cycle. All heifers were slaughtered on Day 7 of the present cycle. The site of EB was visually evident in 40% (4/10) of Group 1 and 42% (3/7) of Group 2 heifers. Histological assessment revealed no evidence of changes indicative of endometritis in either the biopsied or non-biopsied horns in both groups. The histological iii changes observed included mild mononuclear infiltration of the epithelium and mild vascular changes associated with haemorrhage and congestion.Initial investigation of the endometrial expression of the pro-inflammatory cytokine IL1β and wound healing cytokine TGFβ genes found no significant difference betwe...

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“…More than 20 years ago Betteridge and Fléchon [21] stated: "So much embryological information and teaching material is based on the extensive studies of early development in Fig. 3 A selection of transcriptionally conserved and divergent pathways mediating pluripotency and differentiation of murine and human embryonic stem cells mice and humans that there is a real danger of being misled by consequent extrapolations and assumptions".…”

Section: Discussionmentioning

confidence: 99%

Constraints to Progress in Embryonic Stem Cells from Domestic Species

Muñoz

Trigal

Molina

et al. 2009

Stem Cell Rev and Rep

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Domestic animal embryonic stem cells are of potentially big value in transgenic research and studies of lineage commitment and development. Unfortunately, despite many efforts, validated embryonic stem cell lines in species other than mice and primates are yet to be isolated. Here we review some factors that might help to explain why derivation of domestic animal embryonic stem cells is still unsuccessful. Keywords Embryonic stem cells . Domestic speciesSince the first embryonic stem cell lines isolation from mouse embryos in 1981 [1, 2] the number of published articles dealing with these unique cells has steadily increased ( Fig. 1. Pubmed citations dated on January 1981-December 2008). The rise in the number of publications can be taken as a reflection of the interest aroused by these cells due to their unique biological properties and numerous applications.Stem cells derived from early embryos (Embryonic Stem Cells; ESC) are cultured cell lines that can be clonally propagated and maintained in culture indefinitely, while their ability to differentiate in vitro or in vivo into derivatives of all three germ layers remains preserved. Thus, ESC can contribute to form all tissues and organs, including germ cells. These singular traits have made ESC a useful tool for studying mammalian development, nuclear reprogramming, and cell lineage commitment and differentiation.Manipulation of ESC by homologous recombination is highly efficient [3], which provides a route for the precise modification of the animal genome by gene targeting. Currently, genetically modified mice are routinely produced by embryonic stem cell technology [4]. Transgenic mice are essential tools in the understanding of functional genomics, mammalian physiology and as animal models for a number of human diseases.Several animal reproductive biology research initiatives have envisaged the production of gene-targeted farm animals for improving productive traits and disease resistance and as models for human diseases. Such farm species would not show some of the limitations of the mouse model i.e. short life span or a physiology and anatomy very different from humans. Unfortunately, contrary to mice and primates, a key barrier to genetic modification in livestock has been the failure to establish embryonic stem cell lines from domestic species, which remains as a multi-faceted challenge. As pointed-out within several recent reviews [5][6][7][8][9], progress in ESC will arise from research focusing on the understanding of species-specific mechanisms that maintain pluripotency; identification of appropriate stem cell markers; and optimization of culture conditions.The existence of significant morphological and functional similarities between ESC from very different species [10,11] might have led researchers to an inappropriate, direct application on farm species of specific conditions used to isolate and maintain ESC from mice and humans. As a result of this misconception, and provided that important differences have also been observed [11], we n...

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The anatomy and physiology of pre-attachment bovine embryos

Cited by 227 publications

References 120 publications

Cellular evaluation of bovine nuclear transfer embryos developed in vitro

Cellular evaluation of bovine nuclear transfer embryos developed in vitro

63 Effect of Endometrial Biopsy on Uterine Health of Tropically Adapted Beef Cattle

Constraints to Progress in Embryonic Stem Cells from Domestic Species

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