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

Abstract

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.

Prosurvival effect of cumulus prostaglandin G/H synthase 2/prostaglandin2 signaling on bovine blastocyst: impact on in vivo posthatching development†

“…The quality of the preovulatory follicle has been identified as being one of the major reasons for pregnancy losses at the start of pregnancy [ 22 , 23 ]. The developmental potential of the oocyte has been shown to be reflected in cumulus gene expression [ 24 , 25 ]. Higher prostaglandin G/H synthase-2 (PTGS2) expression in the human periconceptional cumulus is correlated with oocytes that develop into higher quality embryos [ 26 ].…”

Evolution of egg coats: linking molecular biology and ecology

“…; Assidi et al . ), ecologists are typically interested in their functional role and fitness consequences (e.g. Salthe ; Pechenik ; Podolsky ; Bovill et al .…”

“…Wong & Wessel 2006;Izquierdo-Rico et al 2009;Pang et al 2011) and medical researchers in linking their variation to pregnancy (e.g. Host et al 2002;Assidi et al 2015), ecologists are typically interested in their functional role and fitness consequences (e.g. Salthe 1963;Pechenik 1979;Podolsky 2002;Bovill et al 2015).…”

Cumulus Cell Genes as Potential Biomarkers of Oocyte and Embryo Developmental Competence

“…Нині цей відбір ґрунтується на таких морфологічних показниках, як швидкість росту, раннє дроблення, ступінь фрагментації, формування бластоцисти [1][2][3][4]. Однак прогностична можливість цього під-ходу обмежена, оскільки він є суб'єктивним і недостатньо точним [1,2,[4][5][6]. Морфоло-гічний зовнішній вигляд ооцита і ембріона не дає адекватного прогнозу їх розвитку.…”

“…Врешті решт, численні гени в КК могли б бути потенцій-ними маркерами для діагностики здатності розвитку ооцитів та ембріонів [3,5,8,32,33]. Треба визначити профіль їх експресії, важли-вий для селекції ембріона, провести дослід-ження, щоб виявити зв'язок між зміненою експресією мРНК в КК і розвитком ембріона, його життєздатністю.…”