Gene expression in bovine embryos derived from oocytes with different developmental competence collected at the defined follicular developmental stage

Němcová, Lucie; Machatkova, Marie; Hanzalova, K.; Horakova, J.; Kaňka, Jiří

doi:10.1016/j.theriogenology.2005.08.006

Cited by 25 publications

(21 citation statements)

References 40 publications

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“…Cx43, a maternal gene important in early embryo development, is a critical protein in preimplantation development. It is a marker of developmental potential for bovine embryos derived from oocytes with different developmental competences; in other words, low Cx43 expression is an indicator of blastocysts with low developmental competence, which is commonly seen in thawed embryos [28,29]. Interferon tau is a key factor that controls the expression of several trophoblast-related factors that prepare the uterus for placental attachment, alter the uterine immune system and regulate early conceptus development [30,31].…”

Section: Expression Of Developmentally Important Genesmentioning

confidence: 99%

Effects of Repetitive Ionomycin Treatment on <i>In Vitro</i> Development of Bovine Somatic Cell Nuclear Transfer Embryos

Kim¹,

Lee²,

Jeong³

et al. 2012

Journal of Reproduction and Development

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Abstract. To artificially activate embryos in somatic cell nuclear transfer (SCNT), chemical treatment with ionomycin has been used to induce transient levels of Ca 2+ and initiate reprogramming of embryos. Ca 2+ oscillation occurs naturally several times after fertilization (several times with 15-to 30-min intervals). This indicates how essential additional Ca 2+ influx is for successful reprogramming of embryos. Hence, in this report, the experimental design was aimed at improving the developmental efficiency of cloned embryos by repetitive Ca 2+ transients rather than the commonly used ionomycin treatment (4 min). To determine optimal Ca 2+ inflow conditions, we performed three different repetitive ionomycin (10 μM) treatments in reconstructed embryos: Group 1 (4-min ionomycin treatment, once), Group 2 (30-sec treatment, 4 times, 15-min intervals) and Group 3 (1-min treatment, 4 times, 15-min intervals). Pronuclear formation rates were checked to assess the effects of repetitive ionomycin treatment on reprogramming of cloned embryos. Cleavage rates were investigated on day 2, and the formation rates of blastocysts (BLs) were examined on day 7 to demonstrate the positive effect of repeated ionomycin treatment. In Group 3, a significant increase in BL formation was observed [47/200 (23.50%), 44/197 (22.33%) and 69/195 (35.38%) in Groups 1, 2 and 3, respectively]. Culturing embryos with different ionomycin treatments caused no significant difference among the groups in terms of the total cell number of BLs (164.3, 158.5 and 145.1, respectively). Additionally, expression of the anti-apoptotic Bcl-2 gene and MnSOD increased significantly in Group 3, whereas the expression of the pro-apoptotic Bax decreased statistically. In conclusion, the present study demonstrated that repeated ionomycin treatment is an improved activation method that can increase the developmental competence of SCNT embryos by decreasing the incidence of apoptosis. Key words: Apoptosis, Bovine embryos, Ca 2+ oscillation, SCNT (J. Reprod. Dev. 58: [132][133][134][135][136][137][138][139] 2012) C a 2+ oscillation is a universal signaling cue that activates numerous cellular responses. Ca 2+ signaling is ubiquitous in some somatic cells and germ lines. In particular, in early embryo development, the fluctuating Ca 2+ concentration is a factor that brings about serial developmental mechanisms [1]. After fertilization, matured oocytes arrested in the metaphase stage of the second meiotic division (MII) turn into zygotes with subsequent signaling events such as depolarization, Ca 2+ oscillation, cortical reaction and pronucleus formation [2,3]. The exit from MII resumption and the further processes for forthcoming development do not occur before the concentration of intracellular Ca 2+ is increased by sperm penetration. Sperm is the initial signal for Ca 2+ release mediated by IP 3 (inositol trisphosphate), protein tyrosine kinases and PLC gamma (PLC-ζ in mammals), followed by reorganization of Ca 2+ -releasing machinery to trigger subsequent s...

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Section: Expression Of Developmentally Important Genesmentioning

confidence: 99%

Effects of Repetitive Ionomycin Treatment on <i>In Vitro</i> Development of Bovine Somatic Cell Nuclear Transfer Embryos

Kim¹,

Lee²,

Jeong³

et al. 2012

Journal of Reproduction and Development

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“…The intercellular structures are altered in the IVP embryos (Boni et al 1999), and the expression of genes responsible for compaction and cell-to-cell adhesion, such as GJA1 (CX43) and E-cadherin (CDH1), is diminished (Wrenzycki et al 1996, 2001, Rizos et al 2002. A low expression of GJA1 has been associated to low quality of IVP blastocysts (Lonergan et al 2003a, 2003b, Rizos et al 2003, low Development and gene expression in parthenotes developmental competence as oocytes (Nemcova et al 2006), and reduced survival to cryopreservation (Rizos et al 2002). CDH1 intervenes in cell-to-cell adhesion as it associates to compaction (Pratt et al 1982, Fleming et al 1984, while its transcripts are found at comparable levels in the ICM and TE of bovine blastocysts (Shehu et al 1996, Barcroft et al 1998, Wrenzycki et al 2003.…”

Section: Development and Gene Expression In Parthenotesmentioning

confidence: 99%

Biological differences between in vitro produced bovine embryos and parthenotes

Gómez¹,

Gutiérrez‐Adán²,

Díez³

et al. 2009

Reproduction

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Parthenotes may represent an alternate ethical source of stem cells, once biological differences between parthenotes and embryos can be understood. In this study, we analyzed development, trophectoderm (TE) differentiation, apoptosis/necrosis, and ploidy in parthenotes and in vitro produced bovine embryos. Subsequently, using real-time PCR, we analyzed the expression of genes expected to underlie the observed differences at the blastocyst stage. In vitro matured oocytes were either fertilized or activated with ionomycin C6-DMAP and cultured in simple medium. Parthenotes showed enhanced blastocyst development and diploidy and reduced TE cell counts. Apoptotic and necrotic indexes did not vary, but parthenotes evidenced a higher relative proportion of apoptotic cells between inner cell mass and TE. The pluripotence-related POU5F1 and the methylation DNMT3A genes were downregulated in parthenotes. Among pregnancy recognition genes, TP-1 was upregulated in parthenotes, while PGRMC1 and PLAC8 did not change. Expression of p66 shc and BAX/BCL2 ratio were higher, and p53 lower, in parthenotes. Among metabolism genes, SLC2A1 was downregulated, while AKR1B1, PTGS2, H6PD, and TXN were upregulated in parthenotes, and SLC2A5 did not differ. Among genes involved in compaction/blastulation, GJA1 was downregulated in parthenotes, but no differences were detected within ATP1A1 and CDH1. Within parthenotes, the expression levels of SLC2A1, TP-1, and H6PD, and possibly AKR1B1, resemble patterns described in female embryos. The pro-apoptotic profile is more pronounced in parthenotes than in embryos, which may differ in their way to channel apoptotic stimuli, through p66 shc and p53respectively, and in their mechanisms to control pluripotency and de novo methylation.Reproduction (2009) 137 285-295

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“…McKenzie et al [69] showed that the expression of PTGS2, HAS2 and GREM1 genes in CCs was higher from oocytes that developed into higher quality embryos compared with lower quality embryos. Similarly, Nemcova et al [70] also showed that the level of Cx43 transcript was greater in embryos derived from oocytes with greater developmental competence compared with those derived from oocytes with lesser developmental competence. Thus, these authors suggested these genes as a reliable indicator of the oocyte quality.…”

Section: Hormonal Stimulationmentioning

confidence: 83%

“…There may not be a single common reason that explains the differential gene expression between the COH protocols, but what is important and certain is that gene expression in the granulose cells of periovulatory follicles is highly dependent on the specific gonadotrophin regimens used for COH. In humans [69] and bovines [70] gene expression in the granulose cells has been correlated with oocyte developmental competence. McKenzie et al [69] showed that the expression of PTGS2, HAS2 and GREM1 genes in CCs was higher from oocytes that developed into higher quality embryos compared with lower quality embryos.…”

Section: Hormonal Stimulationmentioning

confidence: 99%

Factors Influencing the Biochemical Markers for Predicting Mammalian Oocyte Quality

Ola

Sun

2012

Journal of Reproduction and Development

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Abstract. The need for accurate selection of the best oocytes for in vitro fertilization protocols and thus, production of embryos has driven the search for oocyte quality markers from morphological criteria to biochemical parameters. Current studies are focused on the biochemical constituents of the follicular fluid and gene expression profiling of the cumulus cells. These parameters are, however, affected by factors that must be considered before making a judgment of the oocyte's quality. These includes factors such as the type of hormonal stimulation protocol, age of oocyte donor and heat stress on the donor, all of which have been reported to influence the concentrations of many hormones, apolipoproteins, metabolites, fatty acids and growth factors in the follicular fluid and the expression of several genes in the cumulus cells. Another important point to note is species variation in the response to these extraneous influences, which thus calls for species targeted investigations. As reports are still scanty and investigations assumed to be very keen, we employed this review paper to bring attention of researchers and clinicians to those factors that may come to bear on the outcome of their investigations on oocyte and embryo quality. Key words: Cumulus cells, Follicular fluid, Mammalian oocytes, Quality prediction (J. Reprod. Dev. 58: [385][386][387][388][389][390][391][392] 2012) I t is well known that only part of the in vivo ovulated oocytes and in vitro matured oocytes are capable of developing to viable embryos after fertilization. This led to the search for a reliable indicator of oocyte quality. Thus, one of the important puzzles for reproductive biologists today is the search for a reliable noninvasive marker of the quality of oocytes for both human and animal assisted reproduction.Initial attempts at evaluating the quality of oocytes meant for in vitro fertilization (IVF) focused on the physical/morphological characteristics of the Cumulus-oocyte-complexes (COCs) [1,2]. These criteria are both noninvasive and rapid and are still generally in use today. However, recent reports on the inadequacies of a simple morphological appearance as a measure of quality suggest that morphological markers cannot be completely relied upon [3,4]. This has led to intensification of the search for alternative or complementary criteria with focus on the follicular fluid (FF) and the cumulus cells (CCs) around the oocyte.The preovulatory oocyte communicates intimately and directly with the surrounding cumulus granulosa cells through specialized transzonal cytoplasmic projections [5] and with the more distant mural granulosa cells through the follicular fluid [6]. Many biochemical substances found in these close associates of the oocyte have been studied and correlated with the developmental competence of the oocyte. Very recent attempts are even looking beyond a single substance to the totality of the biochemical constituents of the follicular fluid. This area of research is referred to as metabolomics [7]. Revelli e...

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Gene expression in bovine embryos derived from oocytes with different developmental competence collected at the defined follicular developmental stage

Cited by 25 publications

References 40 publications

Effects of Repetitive Ionomycin Treatment on <i>In Vitro</i> Development of Bovine Somatic Cell Nuclear Transfer Embryos

Effects of Repetitive Ionomycin Treatment on <i>In Vitro</i> Development of Bovine Somatic Cell Nuclear Transfer Embryos

Biological differences between in vitro produced bovine embryos and parthenotes

Factors Influencing the Biochemical Markers for Predicting Mammalian Oocyte Quality

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