Expression Profile of Genes as Indicators of Developmental Competence and Quality of In Vitro Fertilization and Somatic Cell Nuclear Transfer Bovine Embryos

Abstract

Reproductive biotechnologies such as in vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT) enable improved reproductive efficiency of animals. However, the birth rate of in vitro-derived embryos still lags behind that of their in vivo counterparts. Thus, it is critical to develop an accurate evaluation and prediction system of embryo competence, both for commercial purposes and for scientific research. Previous works have demonstrated that in vitro culture systems induce alterations in the relative abundance (RA) of diverse transcripts and thus compromise embryo quality. The aim of this work was to analyze the RA of a set of genes involved in cellular stress (heat shock protein 70-kDa, HSP70), endoplasmic reticulum (ER) stress (immunoglobulin heavy chain binding protein, Bip; proteasome subunit β5, PSMB5) and apoptosis (BCL-2 associated X protein, Bax; cysteine aspartate protease-3, Caspase-3) in bovine blastocysts produced by IVF or SCNT and compare it with that of their in vivo counterparts. Poly (A) + mRNA was isolated from three pools of 10 blastocysts per treatment and analyzed by real-time RT-PCR. The RA of three of the stress indicators analyzed (Bax, PSMB5 and Bip) was significantly increased in SCNT embryos as compared with that of in vivo-derived blastocysts. No significant differences were found in the RA of HSP70 and Caspase-3 gene transcripts. This study could potentially complement morphological analyses in the development of an effective and accurate technique for the diagnosis of embryo quality, ultimately aiding to improve the efficiency of assisted reproductive techniques (ART).

Molecular cloning and expression of FGF2 gene in pre‐implantation developmental stages of in vitro‐produced sheep embryos

“…A better knowledge about gene expression patterns during early embryo development would give an accurate evaluation and prediction system of embryo competence, both for commercial purposes and for scientific research (Cánepa et al., ). It is necessary to have a better understanding of stage‐specific gene expression because each stage of embryo is characterized by temporal and spatial activation of a specific subset of genes (Ko et al., ).…”

“…As anticipated, the homology of the cloned sheep embryo FGF2 with cattle FGF2 was very high (100% in terms of both nucleotide and amino acid sequence, respectively), whereas a lower degree of similarity was noticed between rat and mouse (69.2% and 98.2%, respectively). At nucleotide level, changes were observed from T to A better knowledge about gene expression patterns during early embryo development would give an accurate evaluation and prediction system of embryo competence, both for commercial purposes and for scientific research (Cánepa et al, 2014). It is necessary to have a better understanding of stage-specific gene expression because each stage of embryo is characterized by temporal and spatial activation of a specific subset of genes (Ko et al, 2000).…”

Lack of effects of ooplasm transfer on early development of interspecies somatic cell nuclear transfer bison embryos

“…In the last decade, revolutionary disciplines, such as transcriptomics have allowed comprehension of complex processes occurring during early development [ 33 ]. Quantification of transcripts in embryos has been used to assess embryo developmental competence in vitro and in vivo [ 34 , 35 ]. However, very few OT reports have included PCR studies to understand the interactions taking place between ooplasmic and nuclear components.…”

Baicalin increases developmental competence of mouse embryos <i>in vitro</i> by inhibiting cellular apoptosis and modulating <i>HSP70</i> and DNMT expression

“…Apart from morphological criteria, expression levels of developmentally important genes have also been monitored to assess blastocyst quality [4, 20], which may explain how baicalin improves developmental competence of mouse embryos in vitro . The level of Gja1 mRNA, which is one of the gap junction proteins, has been shown to be higher in in vivo derived mouse and bovine blastocysts compared to those produced in vitro [15, 28], which is consistent with the higher quality blastocysts recorded in terms of cryotolerance [29].…”

“…Previously, it has been reported that in vitro culture conditions can lead to increased incidence of cellular stress and apoptosis [15, 16] and induce aberrant DNA methylation in mouse embryos [17, 18], both of which may result in decreased blastocyst quality and even affect the viability of offspring after transfer into a surrogate. Gene expression analysis, a preferred method over conventional criteria like embryo morphology and developmental rates [19], has commonly been used to assess embryo quality and to optimize in vitro culture conditions [20]. Therefore, in this study, a group of marker genes related to cellular stress and apoptosis, and DNA methylation were measured to explore the regulatory mechanism of baicalin in developmental competence of mouse embryos in vitro .…”