Analysis of the Ultrastructure of the Canine Zona Pellucida

Lunn, Matthew O.; Wright, Shirley J.

doi:10.1017/s1431927606066281

Cited by 2 publications

(5 citation statements)

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“…According to CCs gene expression data, we confirmed herein the complexity of molecular and signalling events that drives the final steps of oocyte maturation, its interplay with CCs and ovulation. Since this study is comparing two treatment groups with different ZP birefringences, it is important to highlight that this oocyte’s coat remain in the oocyte immediate vicinity since the oocyte growth and maturation and remains during the early embryo development until hatching [ 23 , 24 ]. ZP structure is based on filaments of ZP2-ZP3 heterodimers proteins, linked in some binding sites by ZP1[ 26 ].…”

Section: Discussionmentioning

confidence: 99%

“…It is involved in vital functions related to ovarian function and oocyte quality as summarized in figures 2 and 5 following gene function analysis using IPA software. In fact, ZP is a filamentous matrix located in the perivitelline space around the oocyte and composed of well-structured and highly- glycosylated glycoproteins [ 24 , 28 ]. ZP genes transcription and their glycoprotein synthesis are reported in both the oocyte and CCs of most mammals and involved in maintaining both COCs and ZP morphologies (Figures 2 and 4 ), prevent polyspermy and protect early embryo development until the blastocyst hatching [ 25 ].…”

Section: Discussionmentioning

confidence: 99%

“…ZP genes’ transcription and glycoprotein synthesis are reported in both the oocyte and CCs of most mammals. This ZP acts as an oocyte’s coat since the oocyte growth and maturation, remains during the early embryo development until the blastocyst hatching [ 23 , 24 ]. Its thickness increases with the oocyte maturation progression to reach around 17 µm at the human MII stage [ 25 ].…”

Section: Introductionmentioning

confidence: 99%

“…ZP is also marked by layers of long filaments with repetitive protein heterodimers ZP2-ZP3 cross-linked by ZP1 homodimers [ 26 , 27 ]. ZP proteins’ glycosylation is maximal in the outer layers and decreases progressively to a more compact and less porous inner region [ 24 , 28 ]. In human and mice, ZP3 is crucial for sperm recognition and fertilization [ 27 , 29 - 31 ].…”

Section: Introductionmentioning

confidence: 99%

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Use of Both Cumulus Cells’ Transcriptomic Markers and Zona Pellucida Birefringence to Select Developmentally Competent Oocytes in Human Assisted Reproductive Technologies

2015

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BackgroundSelection of the best oocyte for subsequent steps of fertilization and embryo transfer was shown to be the crucial step in human infertility treatment procedure. Oocyte selection using morphological criteria mainly Zona pellucida (ZP) has been the gold standard method in assisted reproductive technologies (ART) clinics, but this selection approach has limitations in terms of accuracy, objectivity and constancy. Recent studies using OMICs-based approaches have allowed the identification of key molecular markers that quantitatively and non-invasively predict the oocyte quality for higher pregnancy rates and efficient infertility treatment. These biomarkers are a valuable reinforcement of the morphological selection criteria widely used in in vitro fertilization (IVF) clinics. In this context, this study was designed to investigate the relationship between transcriptomic predictors of oocyte quality found by our group and the conventional morphological parameters of oocyte quality mainly the ZP birefringence.ResultsMicroarray data revealed that 48 and 27 differentially expressed candidate genes in cumulus cells (CCs) were respectively overexpressed and underexpressed in the ZGP (Zona Good Pregnant) versus ZBNP (Zona Bad Non Pregnant) groups. More than 70% of previously reported transcriptomic biomarkers of oocyte developmental competence were confirmed in this study. The analysis of possible association between ZP birefringence versus molecular markers approach showed an absence of correlation between them using the current set of markers.ConclusionsThis study suggested a new integrative approach that matches morphological and molecular approaches used to select developmentally competent oocytes able to lead to successful pregnancy and the delivery of healthy baby. For each ZP birefringence score, oocytes displayed a particular CCs' gene expression pattern. However, no correlations were found between the 7 gene biomarkers of oocyte developmental potential and the ZP birefringence score. Further studies using larger lists of candidate markers are required to identify suitable genes that are highly correlated with the morphological criteria, and therefore able to reinforce the accuracy of oocyte selection and the effectiveness of infertility treatment.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Use of Both Cumulus Cells’ Transcriptomic Markers and Zona Pellucida Birefringence to Select Developmentally Competent Oocytes in Human Assisted Reproductive Technologies

2015

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“…These events are mainly induced by FSH stimulation [ 22,69 ] . At the antral stage, the zona pellucida (ZP), which is a fi lamentous glycoprotein-based matrix secreted around the oocyte, reaches its fi nal differentiation, and the CCs cover the COC [ 70,71 ] . Just prior to ovulation and following the LH surge, CCs respond by volumetric enlargement of the extracellular space (CC expansion), which is required for the oocyte's fi nal maturation, ovulation, and fertilization [ 7,72 ] .…”

Section: Cumulus Cell Phenotype As An Indicator Of Follicular Stagementioning

confidence: 99%

Cumulus Cell Gene Expression as a Marker of Oocyte Quality

Assidi

Sirard

2012

Oogenesis

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Cumulus cells (CCs) are a highly specialized cell type that surround the mammalian oocyte from antrum formation to the early stages of embryo development in the oviduct. During this period of close vicinity, CCs maintain paracrine and cell-to-cell communications with the oocyte. The increasing use of CCs to predict oocyte quality requires a growing understanding of their involvement in oocyte developmental competence acquisition. This chapter highlights the current knowledge about CC differentiation and communications with the oocyte. Special focus is given to the molecular biomarkers differentially expressed in CCs that re fl ect higher oocyte quality and therefore are associated with successful embryo development and/or implantation. The biological, signaling, and molecular functions and/or pathways of CCs during oocyte maturation, ovulation, fertilization, and early embryo development are also discussed. Using recent fi ndings in other tissues/species, some hypotheses about the processes whereby CCs exert their functions are suggested. Further characterization will be required to re fi ne these biomarkers in order to improve both animal and human ART.

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Analysis of the Ultrastructure of the Canine Zona Pellucida

Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005

Cited by 2 publications

References 1 publication

Use of Both Cumulus Cells’ Transcriptomic Markers and Zona Pellucida Birefringence to Select Developmentally Competent Oocytes in Human Assisted Reproductive Technologies

Use of Both Cumulus Cells’ Transcriptomic Markers and Zona Pellucida Birefringence to Select Developmentally Competent Oocytes in Human Assisted Reproductive Technologies

Cumulus Cell Gene Expression as a Marker of Oocyte Quality

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