Morphological Evaluation of Embryos in Domestic Species

Merton, S.

doi:10.1007/978-94-010-0343-8_2

Cited by 15 publications

(13 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It has been recently shown that stereomicroscopic evaluation of porcine blastocysts is correlated with ultrastructural alterations and cell death (Cuello et al 2007). This observation, along with previous observations that blastocysts with greater total cell numbers often result in higher pregnancy and birth rates than those with lower total cell numbers (Merton 2002), suggests that our grade 1 blastocysts were of better quality than our grade 3 blastocysts (because the former contained more cells than the latter), and that bOF treatment stimulated cleavage and the production of blastocysts with higher number of cells than in the control group for grade 3 and 4 blastocysts.…”

Section: Discussionsupporting

confidence: 83%

Effects of oviductal fluid on the development, quality, and gene expression of porcine blastocysts produced in vitro

Lloyd¹,

Romar²,

Matás³

et al. 2009

Reproduction

View full text Add to dashboard Cite

In mammals, fertilization and early pre-implantation development occur in the oviduct. Previous results obtained in our laboratory have identified specific molecules in the oviduct that affect porcine sperm-egg interactions. The aim of the present study was to determine whether the contact between oocytes and oviductal fluid also affect embryo development, quality, and gene expression. In vitro matured porcine oocytes were exposed to bovine oviductal fluid (bOF) for 30 min prior to fertilization. Cleavage and blastocyst development rates were significantly higher from bOF-treated oocytes than from untreated oocytes. Blastocysts obtained from bOF-treated oocytes had significantly greater total cell numbers than those obtained from untreated oocytes. Using real-time PCR, grade 1 (very good morphological quality) and grade 2 (good morphological quality) blastocysts were analyzed for gene transcripts related to apoptosis (BAX, BCL2L1), mitochondrial DNA (mtDNA) transcription/replication (POLG, POLG2, and TFAM), blastomere connection and morula compaction (GJA1), and blastocyst formation and pluripotency (POU5F1). We found that the entire set of genes analyzed was differentially expressed between grade 1 and 2 blastocysts. Furthermore, bOF treatment reduced the ratio of BAX to BCL2L1 transcripts and enhanced the abundance of TFAM transcripts in grade 2 blastocysts. Not only do these findings demonstrate that factors within the bOF act on porcine oocytes both quickly and positively, but they also suggest that such factors could promote embryo development and quality by protecting them against adverse impacts on mtDNA transcription/replication and apoptosis induced by the culture environment.

show abstract

Section: Discussionsupporting

confidence: 83%

Effects of oviductal fluid on the development, quality, and gene expression of porcine blastocysts produced in vitro

Lloyd¹,

Romar²,

Matás³

et al. 2009

Reproduction

View full text Add to dashboard Cite

show abstract

“…In vitro ‐produced embryo quality is the cumulative effect of so many factors, which can roughly be classified as genetic and environmental (culture) factors. So far, morphological classifications (Gordon 1994; Mertons 2002) were used to judge embryo quality. As a result, previous work in our laboratory has showed low cell number (91.6 ± 13.75), and morphological irregularities for bad‐quality blastocyst compared with good‐quality (106 ± 12.76) ones (Kesseler et al.…”

Section: Discussionmentioning

confidence: 99%

Expression of Retinoid X Receptor Transcripts and their Significance for Developmental Competence in In Vitro‐produced Pre‐implantation‐stage Bovine Embryos

Mamo

Ponsuksili

Wimmers

et al. 2005

Reprod Domestic Animals

View full text Add to dashboard Cite

Retinoid X receptors are frequently implicated in their role in embryonic development. However, there is no report regarding their expression in embryos with different qualities. In this study, expression pattern and levels of retinoid X receptor transcripts in different qualities and stages of in vitro-produced pre-implantation bovine embryos were examined using real-time polymerase chain reaction (PCR) techniques. Four independent cDNA pools per sample were prepared from mRNAs isolated from different developmental-stage embryos, after classifying them to be of good and bad quality. Primers were also designed to amplify products with PCR. Based on analysis, except retinoid X receptor gamma (RXRG) transcripts, the remaining two types (alpha and beta forms) were expressed in all samples with significantly higher (p < or = 0.05) levels until the eight-cell stage compared with the stages thereafter. However, the transcript levels for bad-quality embryos were consistently lower in all cases in comparison with good-quality embryos. RXRG was identified in 39% of the samples, but all in the pre-embryonic genome activation development stage. Therefore, strong expression patterns of these transcripts in earlier stages indicates their possible role during the maternal phase of embryo development, and the variations of copy number in embryos with different qualities substantiates their possible candidacy as potential quality markers. Moreover, identifying the transcript variations in different qualities and expression of RXRG at these stages is a novel input to the pre-implantation-stage knowledge.

show abstract

“…In vitro ‐produced bovine pre‐implantation embryos were categorized into three groups (Good, Fair and Poor) at each stage of development considered in this study, based on the International Embryo Transfer Society criteria (Merton 2002) as: Grade I (Good): Symmetrical and spherical embryo mass with individual blastomeres that are uniform in size, colour and density and have at least 85% of the cellular material remains intact; Grade II (Fair): At least 50% of the cellular material should be an intact, viable embryonic mass; moderate irregularities in overall shape of the embryonic mass, size, colour and density of individual cells, ≤ 25% of fragmentation. Grade III (Poor): Major irregularities in shape, size, colour and density; At least 25% of the cellular material should be an intact, viable embryonic mass.…”

Section: Methodsmentioning

confidence: 99%

Expression of Apoptosis Regulatory Genes and Incidence of Apoptosis in Different Morphological Quality Groups of In Vitro-produced Bovine Pre-implantation Embryos

Melka

Rings

Hölker

et al. 2009

Reproduction in Domestic Animals

View full text Add to dashboard Cite

Apoptosis occurs during early development in both in vivo- and in vitro-produced embryos, and is considered as one of the causes of embryonic loss. The objectives of this study were, therefore, investigating stage-specific expression profiles of apoptosis regulatory genes in three quality groups of in vitro-produced bovine pre-implantation embryos; and analysing the relationship between cell number and DNA fragmentation with expressions of those genes. The relative abundance of mRNA of 9 pro- (Bax, caspase-9, Bcl-xs, P53, Caspase-3 and Fas) and anti- (Bcl-w and Mcl-1) apoptotic genes was analysed. Differential cell staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling were performed to analyse the variation in cell numbers and detect apoptotic nuclei respectively. Expression of Bax and Caspase-3 genes was significantly (p < 0.05) higher in poor quality pre-implantation embryos as compared with that of morphologically good quality embryos of the same developmental stages. Moreover, Mcl-1 expression was significantly higher in good quality immature oocytes than that in the poor quality group. Moreover, higher DNA fragmentation was evidenced in morphologically poor quality blastocysts. In conclusion, our study demonstrates that Bax, caspase-3 and Mcl-1 can be used as potential markers of embryo quality to evaluate in vitro-produced bovine embryos. Further studies are required to investigate specific molecular signatures that can be used in evaluating in vivo-derived embryos.

show abstract

Morphological Evaluation of Embryos in Domestic Species

Cited by 15 publications

References 32 publications

Effects of oviductal fluid on the development, quality, and gene expression of porcine blastocysts produced in vitro

Effects of oviductal fluid on the development, quality, and gene expression of porcine blastocysts produced in vitro

Expression of Retinoid X Receptor Transcripts and their Significance for Developmental Competence in In Vitro‐produced Pre‐implantation‐stage Bovine Embryos

Expression of Apoptosis Regulatory Genes and Incidence of Apoptosis in Different Morphological Quality Groups of In Vitro-produced Bovine Pre-implantation Embryos

Contact Info

Product

Resources

About