Regulation of heat-inducible HSPA1A gene expression during maternal-to-embryo transition and in response to heat in in vitro-produced bovine embryos

2017 ◽  
Vol 29 (9) ◽  
pp. 1868 ◽  
Author(s):  
Jean-Marc Lelièvre ◽  
Nathalie Peynot ◽  
Sylvie Ruffini ◽  
Ludivine Laffont ◽  
Daniel Le Bourhis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Heat Shock ◽  
Transcriptional Activation ◽  
Luciferase Activity ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Nuclei ◽  
Cell Stage

In in vitro-produced (IVP) bovine embryos, a burst in transcriptional activation of the embryonic genome (EGA) occurs at the 8–16-cell stage. To examine transcriptional regulation prior to EGA, notably in response to heat stress, we asked (1) whether the spontaneous expression of a luciferase transgene that is driven by the minimal mouse heat-shock protein 1b (hspa1b) gene promoter paralleled that of HSPA1A during EGA in IVP bovine embryo and (2) whether expression of the endogenous heat-inducible iHSPA group member HSPA1A gene and the hspa1b/luciferase transgene were induced by heat stress (HS) prior to EGA. Using two culture systems, we showed that luciferase activity levels rose during the 40-h long EGA-associated cell cycle. In contrast, iHSPA proteins were abundant in matured oocytes and in blastomeres from the two-cell to the 16-cell stages. However, normalised results detected a rise in the level of HSPA1A and luciferase mRNA during EGA, when transcription was required for their protein expression. Prior to EGA, HS-induced premature luciferase activity and transgene expression were clearly inhibited. We could not, however, establish whether this was also true for HSPA1A expression because of the decay of the abundant maternal transcripts prior to EGA. In bovine embryos, heat-induced expression of hspa1b/luciferase, and most likely of HSPA1A, was therefore strictly dependent on EGA. The level of the heat-shock transcription factor 1 molecules that were found in cell nuclei during embryonic development correlated better with the embryo’s capacity for heat-shock response than with EGA-associated gene expression.

236 EFFECT OF HEAT STRESS DURING OOCYTE MATURATION ON GENE EXPRESSION OF IN VITRO-FERTILIZED AND PARTHENOGENETIC BOVINE BLASTOCYSTS

2010 ◽  
Vol 22 (1) ◽  
pp. 276
Author(s):  
F. Q. Costa ◽  
M. M. Pereira ◽  
S. Wohlres-Viana ◽  
R. V. Serapiao ◽  
B. C. Carvalho ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
In Vitro Maturation ◽  
Rna Extraction ◽  
Residual Effect ◽  
Blastocyst Stage ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Peroxiredoxin 1

Heat stress has been shown to have detrimental effects (41°C) during the first 12 h of in vitro maturation on bovine embryo development (Edwards JL and Hansen PJ 1996 Biol. Reprod. 55, 341-346). However, little is known about the effect on gene expression of in vitro-fertilized andparthenogenetic bovine embryos. This study evaluated the gene expression of in vitro-fertilized andparthenogenetic blastocysts derived fromheat-stressed oocytes. The transcripts evaluated were associated with genes encoding proteins involved in blastocoel formation [aquaporin (Aqp) 3 and Na+/K+-ATPase alpha 1; Watson AJ and Barcroft LC 2001 Frontiers Biosci. 6:d708-730] and cell viability (Bax and Peroxiredoxin 1; Van Delft MF and Huang DCS 2006 Cell Res. 16, 203-213; RaguS etal. 2007 PNAS104, 9747-9752). Oocytes were in vitro matured for 12 h at 41°C followed by 12 h at 38.5°C (heat-stressed oocytes; HS) or for 24 h at 38.5°C (non-heat-stressed oocytes; NHS) under 5% CO2. Heat-stressed and NHS oocytes were in vitro fertilized with Holstein sperm (HS-IVF and NHS-IVF subgroups, respectively) or activated with ionomycin and 6-DMAP (HS-PART and NHS-PART subgroups, respectively). Presumptive zygotes were cultured in CR2aa medium under 5% CO2, 5% O2, and 90% N2 at 38.5°C. Embryos at blastocyst stage with same quality grade for all subgroups were obtained from 3 different replicates and distributed in pools of 10 embryos for relative quantification of the target transcripts. RNA extraction and reverse transcription were performed and cDNA quantified by real-time PCR. Transcripts of H2a gene were used as endogenous control, and statistical analysis was performed by pair-wise, fixed reallocation randomization test. Gene expression comparisons were performed between HS-IVF and NHS-IVF, HS-PART and NHS-PART, NHS-PART and NHS-IVF, and HS-PART and HS-IVF subgroups. Blastocyst rate is shown as mean ± SEM and relative expression as n-fold. The heat stress on oocytes during in vitro maturation decreased (P < 0.05, ANOVA) the development of presumptive zygotes to blastocyst stage at Day 8 for in vitro-fertilized (19.9 ± 2.9% and 10.5 ± 2.0% for NHS-IVF and HS-IVF, respectively) and parthenogenetic (33.0 ± 1.8% and 22.8 ± 2.8% for NHS-PART and HS-PART, respectively) embryos. Embryos from the HS-IVF subgroup showed less (P < 0.01) expression of Na+/K+-ATPase alpha 1 (0.67-fold) than did NHS-IVF embryos, whereas no difference was found for others genes. Embryos from the HS-PART subgroup showed less (P < 0.01) expression of Aqp 3 (0.77-fold) and greater (P < 0.05) expression of Bax (1.40-fold) than did NHS-PART embryos. Expression of Aqp 3 was up-regulated (P < 0.01) in NHS-PART (1.42-fold) embryos when compared with NHS-IVF ones, whereas expression of Na+/K+-ATPase alpha 1 (1.42-fold), Bax (1.67-fold), and Peroxiredoxin 1 (1.40-fold) were up-regulated (P < 0.05) in HS-PART embryos when compared with HS-IVF embryos. In conclusion, heat stress on oocytes during in vitro maturation can affect the amount of transcripts of in vitro-fertilized andparthenogenetic blastocysts, suggesting a residual effect on gene expression of bovine embryos. Financial support was provided by CNPq and FAPEMIG.

The requirement for protein kinase C delta (PRKCD) during preimplantation bovine embryo development

2016 ◽  
Vol 28 (4) ◽  
pp. 482 ◽  
Author(s):  
Qi-En Yang ◽  
Manabu Ozawa ◽  
Kun Zhang ◽  
Sally E. Johnson ◽  
Alan D. Ealy
Keyword(s):  
Gene Expression ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Embryonic Development ◽  
Embryo Development ◽  
Early Embryonic Development ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Kinase C

Protein kinase C (PKC) delta (PRKCD) is a member of the novel PKC subfamily that regulates gene expression in bovine trophoblast cells. Additional functions for PRKCD in early embryonic development in cattle have not been fully explored. The objectives of this study were to describe the expression profile of PRKCD mRNA in bovine embryos and to examine its biological roles during bovine embryo development. Both PRKCD mRNA and protein are present throughout early embryo development and increases in mRNA abundance are evident at morula and blastocyst stages. Phosphorylation patterns are consistent with detection of enzymatically active PRKCD in bovine embryos. Exposure to a pharmacological inhibitor (rottlerin) during early embryonic development prevented development beyond the eight- to 16-cell stage. Treatment at or after the 16-cell stage reduced blastocyst development rates, total blastomere numbers and inner cell mass-to-trophoblast cell ratio. Exposure to the inhibitor also decreased basal interferon tau (IFNT) transcript abundance and abolished fibroblast growth factor-2 induction of IFNT expression. Furthermore, trophoblast adhesion and proliferation was compromised in hatched blastocysts. These observations provide novel insights into PRKCD mRNA expression profiles in bovine embryos and provide evidence for PRKCD-dependent regulation of embryonic development, gene expression and post-hatching events.

148 EFFECT OF FOLLISTATIN TREATMENT POST-FERTILIZATION ON TIME TO FIRST CLEAVAGE, DEVELOPMENT TO THE BLASTOCYST STAGE, AND CELL ALLOCATION OF IN VITRO-PRODUCED BOVINE EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 191
Author(s):  
K. B. Lee ◽  
A. Bettegowda ◽  
J. J. Ireland ◽  
G. W. Smith
Keyword(s):  
Blastocyst Stage ◽  
Total Cell ◽  
Mrna Abundance ◽  
Differential Staining ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Oocyte Competence ◽  
Trophectoderm Cells

Previous studies from our laboratory have demonstrated a positive association of follistatin mRNA abundance with oocyte competence. Follistatin mRNA is greater in germinal vesicle stage oocytes collected from prepubertal (model of poor oocyte competence) vs. adult animals. Furthermore, follistatin mRNA abundance is also greater in early-cleaving 2-cell bovine embryos (collected prior to the maternal zygotic transition and initiation of significant transcription from the embryonic genome) than their late-cleaving counterparts. Given these results and the fact that early-cleaving embryos develop to the blastocyst stage at a greater rate, we hypothesized that follistatin has a stimulatory role in early embryonic development. To begin to test this hypothesis, we determined the effects of follistatin treatment of in vitro-produced bovine embryos (during the initial 72 h post-fertilization) on time to first cleavage, development to the blastocyst stage (Day 7), and blastocyst cell allocation (quality). Cumulus–oocyte complexes (COCs) were harvested from ovaries obtained from a local abattoir, matured, and fertilized in vitro. After 20 h of co-incubation with spermatozoa, presumptive zygotes were stripped of cumulus cells and cultured in KSOM medium supplemented with 0.3% BSA containing 0, 1, 10, or 100 ng mL-1 follistatin (n = 25 presumptive zygotes per treatment; n = 6 replicates). Proportions of embryos reaching the 2-cell stage within 30 h (early-cleaving), 30–36 h (late-cleaving), and within 48 h post-fertilization (total cleavage rate) were recorded. Embryos at the 8–16-cell stage were separated 72 h after fertilization and cultured in fresh KSOM medium supplemented with 0.3% BSA and 10% FBS until Day 7. The proportion of embryos reaching the blastocyst stage at Day 7 post-fertilization was recorded and the numbers of inner cell mass (ICM) and trophectoderm (TE) cells determined by differential staining. Follistatin treatment did not increase the rate of total cleavage and the proportion of late-cleaving embryos when compared to control. However, supplementation with 1 and 10, but not 100, ng mL-1 follistatin increased the proportion of early-cleaving embryos (26.3 and 35.3% vs. 9.5%) and development to the blastocyst stage (28.6 and 31.7% vs. 18.4%) relative to controls (P &lt; 0.05). Treatment with 10 ng mL-1 follistatin increased total cell numbers (130.1 vs. 110.9) and proportion of trophectoderm cells (61.6% vs. 48.4%) and decreased the ICM/total cell ratio (38.4% vs. 51.5%) in Day 7 blastocysts relative to controls (P &lt; 0.05). The results indicate that exogenous follistatin treatment during the early stages of in vitro bovine embryo development can enhance time to first cleavage, development to the blastocyst stage, and cell allocation in favor of increased trophectoderm cells, and can support a potential functional role for follistatin in early embryogenesis.

98 EXPERIMENTAL TRANSFER OF BOVINE IVF-DERIVED 32-CELL STAGE EMBRYOS INTO THE UTERUS: ENVIRONMENTAL EFFECTS ON DEVELOPMENTAL CHARACTERISTICS

2016 ◽  
Vol 28 (2) ◽  
pp. 179
Author(s):  
M. Hoelker ◽  
D. Salilew-Wondim ◽  
F. Rings ◽  
D. Tesfaye ◽  
K. Schellander
Keyword(s):  
Culture Media ◽  
Uterine Cavity ◽  
Blastocyst Stage ◽  
Considerable Proportion ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Developmental Rates ◽  
Uterine Environment

Usually, in vitro-produced bovine embryos are cultured in vitro in static culture systems for 7 to 9 days in media composed according the oviducal fluid although it is well accepted that around Day 4.5–5 the bovine embryo enters the uterine cavity, providing environmental conditions different from the oviduct. Therefore, one has to raise the question whether changing culture media properties after Day 5 of culture could have beneficial effects on early development of bovine embryos. To answer that question, we transferred bovine IVF derived 32-cell stage embryos into the uterine cavity of synchronized recipients. All embryos had been matured and fertilized under routine standard conditions and were cultured in synthetic oviducal fluid supplemented with essential and nonessential amino acids (SOFaa) supplemented with either 0.3% fatty acid free bovine serum albumin (BSAfaf/Uterus) or 10% serum (serum/uterus) at 38.5°C, 5% O2, and 5% CO2 in humidified air prior transfer into the uterine environment, allowing further development to the blastocyst stage within the physiological environment prior recollection at Day 7 by routine uterine flushing followed by comparison with statically in vitro-developed embryos cultured in media supplemented with serum (serum/serum group) or BSAfaf (BSAfaf/BSAfaf group). All in all, a total of 1031 in vitro-derived 32-cell stage embryos were transferred to 21 synchronized Simmental recipient heifers. Of these, a total of 680 embryos (66%) could be recollected at Day 7. Embryos of the serum/serum group reached a higher blastocyst rate compared with embryos of the BSAfaf/BSAfaf group (68% v. 41%; P < 0.05, ANOVA, Tukey test), whereas the developmental rate to the blastocyst stage did not differ after 9 days of in vitro culture, indicating higher developmental kinetics of bovine 32-cell stage embryos when culture media is supplemented with serum. Moreover, embryos of the serum/uterus group reached significantly lower developmental rates to the blastocyst stage until Day 7 compared with embryos of the serum/serum group (12.9% v. 68.4%). Likewise, embryos in the BSAfaf/uterus group reached significantly lower developmental rates to the blastocyst stage until Day 7 compared with embryos in the BSAfaf/BSAfaf group (16.0% v. 40.1%). When allowed to develop for additional 48h in vitro, developmental rates to the blastocyst stage at Day 9 were still higher in BSAfaf/BSAfaf treatment compared with the BSAfaf/uterus treatment (91.4% v. 74.4%) and the serum/serum treatment compared with the serum/uterus treatment (92.5% v. 56.0%). Taken together, the results of our study demonstrate that uterine transfer of bovine 32-cell stage embryos results in reduction of developmental kinetics as well as lower developmental rates compared with embryos statically cultured in vitro. That might indicate, that a considerable proportion of bovine 32-cell stage embryos might not be able to adapt to the uterine environment.

scholarly journals Actions of thermal stress in two-cell bovine embryos: oxygen metabolism, glutathione and ATP content, and the time-course of development

Reproduction ◽  
2004 ◽  
Vol 128 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Rocío Melissa Rivera ◽  
Gabriella M Dahlgren ◽  
Luiz Augusto de Castro e Paula ◽  
Robert T Kennedy ◽  
Peter J Hansen
Keyword(s):  
Heat Shock ◽  
Time Course ◽  
Oxygen Metabolism ◽  
Bovine Embryo ◽  
Atp Content ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Continue Development ◽  
Cellular Physiology ◽  
Radical Production

The mechanism by which heat shock disrupts development of the two-cell bovine embryo was examined. The reduction in the proportion of embryos that became blastocysts caused by heat shock was not exacerbated when embryos were cultured in air (20.95% O2) as compared with 5% O2. In addition, heat shock did not reduce embryonic content of glutathione, cause a significant alteration in oxygen consumption, or change embryonic ATP content. When embryos were heat-shocked at the two-cell stage and allowed to continue development until 72 h post insemination, heat-shocked embryos had fewer total nuclei and a higher percentage of them were condensed. Moreover, embryos became blocked in development at the eight-cell stage. The lack of effect of the oxygen environment on the survival of embryos exposed to heat shock, as well as the unchanged content of glutathione, suggest that free radical production is not a major cause for the inhibition in development caused by heat shock at the two-cell stage. In addition, heat shock appears to have no immediate effect on oxidative phosphorylation since no differences in ATP content were observed. Finally, the finding that heat shock causes a block to development at the eight-cell stage implies that previously reported mitochondrial damage caused by heat shock or other heat shock-induced alterations in cellular physiology render the embryo unable to proceed past the eight-cell stage.

scholarly journals 221 TYPICAL HIF1-REGULATED GENES ARE UNALTERED BY OXYGEN IN BOVINE BLASTOCYSTS

2005 ◽  
Vol 17 (2) ◽  
pp. 261
Author(s):  
A. Harvey ◽  
K. Kind ◽  
J. Thompson
Keyword(s):  
Gene Expression ◽  
Oxygen Concentration ◽  
Hypoxia Inducible Factor ◽  
Fold Increase ◽  
Blastocyst Stage ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Expression Of Genes ◽  
Regulated Gene Expression

Oxygen-regulated gene expression in the bovine embryo contrasts markedly with that observed in the mouse. Under low (2%) post-compaction oxygen conditions moderate changes in gene expression are observed in the bovine blastocyst (Harvey et al. 2004 Biol. Reprod. 71, in press), compared with 3–4 fold increases in the mouse (Kind et al. 2004 Mol. Reprod. Dev., in press). Specifically, GLUT-1 (Harvey et al. 2004), myotrophin, and anaphase-promoting complex 1 (Harvey et al., unpublished) mRNAs are increased in bovine blastocysts following 2% oxygen culture, compared with those cultured under 20% oxygen. These oxygen-mediated differences in gene expression in the bovine are most likely regulated by hypoxia-inducible factor (HIF)2 transcription factor activity, as we have previously observed that HIF1α protein is not detectable in bovine embryos whereas HIF2α is readily detectable (Harvey et al. 2004). The aim of this study was to determine the effect of post-compaction oxygen concentration on the expression of typically HIF1-regulated and potential HIF2-regulated (suggested from a mouse knockout study; Scortegagna et al. 2003 Nat. Genet. 35, 371) genes in bovine blastocysts. In vitro-produced bovine embryos were generated using standard protocols. Compact morulae were randomly allocated to treatments under 2%, 7%, or 20% oxygen for 72 h from Day 5. Blastocyst RNA was isolated using TriReagent (Molecular Research Center, Inc., Cincinnati, OH, USA) and samples were reverse-transcribed using Superscript II (Invitrogen, Melbourne, Australia). Amplification and analysis of cDNA was achieved by real-time PCR using specific primers and Sybr green PCR master mix (Applied BioSystems, Melbourne, Australia). Statistically significant differences in gene expression were analyzed by ANOVA, P < 0.05. Examination of expression of genes known to be regulated by HIF1 in somatic cells (reviewed by Semenza 2002 Biochem. Pharm. 64, 993) revealed no oxygen-mediated alteration in expression of aldose reductase, cyclooxygenase 2, or inducible nitric oxide synthase. However, the expression of lactate dehydrogenase A (LDHA) displayed a 4-fold increase under 2% oxygen, compared with 7% and 20% oxygen (P < 0.001). Expression of glutathione peroxidase, and CuZn- and Mn-superoxide dismutase (putative HIF2-regulated genes) was not influenced by oxygen concentration post-compaction. This study suggests that typical HIF1-regulated genes are not influenced by alterations in the external oxygen environment in the bovine embryo. These results complement previous observations that HIF1α protein is not detectable in blastocyst-stage bovine embryos, and suggest that LDHA may be an HIF2 target gene in the bovine embryo. As embryo development is influenced by oxygen concentration, levels of LDHA at the blastocyst stage may be used as a marker of oxygen responsiveness.

scholarly journals Changes in the relative abundance of mRNA transcripts for insulin-like growth factor (IGF-I and IGF-II) ligands and their receptors (IGF-IR/IGF-IIR) in preimplantation bovine embryos derived from different in vitro systems

Reproduction ◽  
2001 ◽  
pp. 601-610 ◽  
Author(s):  
MA Yaseen ◽  
C Wrenzycki ◽  
D Herrmann ◽  
JW Carnwath ◽  
H Niemann
Keyword(s):  
Growth Factor ◽  
Polyvinyl Alcohol ◽  
Blastocyst Stage ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Culture Systems ◽  
Igf I ◽  
Oviduct Fluid

The aim of this study was to determine the relative abundance of mRNAs for the insulin-like growth factor I (IGF-I) and IGF-II ligands, and for the IGF receptors (IGF-IR and IGF-IIR) in in vitro preimplantation bovine embryos from the oocyte to the hatched blastocyst stage using two different culture systems: TCM-199 supplemented with oestrous cow serum, or synthetic oviduct fluid supplemented with polyvinyl alcohol. Development to the two- to four-cell stage and blastocyst stage was significantly higher (P < or = 0.05) in embryos cultured in TCM supplemented with oestrous cow serum than in those cultured in synthetic oviduct fluid supplemented with polyvinyl alcohol (61 and 25% versus 55 and 17%, respectively). A semi-quantitative RT-PCR assay did not detect IGF-I transcripts at any stage of preimplantation bovine development, including the hatched blastocyst stage. In both culture systems, IGF-IR, IGF-II and IGF-IIR were expressed throughout preimplantation development up to the hatched blastocyst stage in a varying pattern. The expression patterns of IGF-IR, IGF-II and IGF-IIR in embryos generated in the two culture systems were not significantly different, except at the expanded blastocyst stage, at which significantly higher amounts of IGF-IIR were observed in the TCM system than in the synthetic oviduct fluid system. These results indicate that transcripts of IGF-IR and IGF-IIR follow the standard pattern in which maternal stores of mRNA in the oocyte are slowly depleted up to the 16-cell stage and then re-established at the onset of embryonic expression of these genes. The lack of detectable IGF-I transcripts in the bovine embryo indicates a predominantly paracrine mode of action. The bovine embryo is capable of producing IGF-II, IGF-IIR and IGF-IR in large amounts, particularly after hatching, which may be important for the formation of the filamentous conceptus. Results indicate an autocrine mechanism for IGF-II and modulation of IGF family expression by culture conditions.

Paternal influence on apoptosis, and expression of BCL2, BAX, TP53, heat shock protein-70 and interferon tau genes in bovine preimplantation embryo

2007 ◽  
Vol 87 (2) ◽  
pp. 157-165 ◽  
Author(s):  
G. Giritharan ◽  
N. Ramakrishnappa ◽  
M. Aali ◽  
P. Madan ◽  
A. Balendran ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Return Rate ◽  
Bovine Embryo ◽  
Interferon Tau ◽  
Expression Levels ◽  
Frozen Semen

The bull effects on apoptosis, and BAX, BCL2, TP53, heat shock protein 70 (HSPA1A) and interferon tau (IFNT) gene expression in in vitro produced embryos were investigated. The degree of correlation of this effect with the 60- to 90-d non-return rates was also investigated. Standard in vitro fertilization and embryo culture were performed using frozen semen from six genetically unrelated bulls. Live, apoptotic, and dead cell percentages in blastocysts were determined, after staining with annexin V, propidium iodide, and bisbenzamide. BAX, BCL2, TP53, HSPA1A and IFNT gene expression levels in blastocysts were determined by RT-PCR. The non-return rate data for all experimental bulls were obtained from a local artificial insemination center. Apoptotic, live and dead blastomere percentages, and HSPA1A and IFNT expression levels in blastocysts were different (P < 0.01) among bulls. BAX, BCL2 and TP53 expression levels were not different among bulls. The non-return rate was highly correlated (P < 0.05) with BCL2 (r = -0.93) or the ratio of BAX to BCL2 (r = 0.84) gene expression. None of the other in vitro fertility parameters were correlated with non-return rate. This study concluded that the development, apoptosis, and HSPA1A and IFNT gene expression of in vitro produced embryos are influenced by individual bulls. Key words: Bovine, embryo, fertility, apoptosis, gene expression, interferon

Insulin, insulin-like growth factors and glucose transporters: temporal patterns of gene expression in early murine and bovine embryos

1992 ◽  
Vol 4 (4) ◽  
pp. 361 ◽  
Author(s):  
GA Schultz ◽  
A Hogan ◽  
AJ Watson ◽  
RM Smith ◽  
S Heyner
Keyword(s):  
Transcriptional Activation ◽  
Preimplantation Embryos ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Rt Pcr ◽  
Cell Stage ◽  
Embryonic Genome ◽  
Igf I ◽  
Murine Embryos ◽  
Receptor Mrnas

mRNA phenotyping by the reverse transcription-polymerase chain reaction (RT-PCR) method was used to compare the patterns of expression of insulin and insulin-like growth factor (IGF) ligand and receptor genes in preimplantation bovine embryos with those established previously for preimplantation murine embryos. In the early bovine embryo, transcripts for IGF-I, IGF-II and mRNAs encoding receptors for insulin, IGF-I and IGF-II were all detectable at all embryo stages from the 1-cell zygote to the blastocyst. In the mouse, IGF-II ligand and receptor mRNAs were not expressed until the 2-cell stage, and the insulin and IGF-I receptor mRNAs were not detectable until the 8-cell stage. Since transcriptional activation of the embryonic genome occurs at the 8- to 16-cell stage in the bovine embryo and at the 2-cell stage in the murine embryo, it is suggested that these transcripts are products of both the maternal and embryonic genomes in the bovine embryo whereas in the mouse they are present only after activation of the embryonic genome. Transcripts for insulin were not detected in preimplantation embryos of either species. Colloidal-gold immunocytochemistry with antibodies directed against the insulin receptor, IGF-I receptor and IGF-I ligand has confirmed the presence of these molecules in bovine blastocysts. RT-PCR and indirect immunofluorescence procedures demonstrated that the glucose transporter (GLUT) isoform 1 is present in murine embryos from the oocyte to blastocyst stage whereas GLUT 2 expression begins at the 8-cell stage.

scholarly journals Effects of supplementation with heat shock cognate 17 KDA protein (HSC70) on in vitro bovine embryo viability

2021 ◽  
Author(s):  
Aimé Jazmín Garza Arredondo ◽  
Diana Elisa Zamora Ávila ◽  
Uziel Castillo Velásquez ◽  
Gustavo Moreno Degollado ◽  
José Fernando De La Torre Sánchez ◽  
...  
Keyword(s):  
Heat Shock ◽  
Blastocyst Stage ◽  
Vital Role ◽  
Control Group ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Embryo Viability ◽  
Stage Of Development

Abstract Endogenous heat shock cognate 71 kDa protein (HSC70) has a vital role in early embryonic development. This study assessed the effects of exogenous HSC70 on bovine embryo development and expression of genes associated with apoptosis. Expression analyses of HSPA1A, HSPA8, Bcl-2, and Bax genes were performed in bovine embryos in vivo on day 7 of development. Subsequently, expression of HSPA1A and HSPA8 were associated with apoptotic genes (Bcl-2 and Bax) in cultured bovine embryos in vitro that were supplemented with various concentrations (0 or control group, 50, and 100 ng) of HSC70. The results indicated that the control group (0 ng) in vitro embryos had higher expression of HSPA8, Bax, and Bcl-2 genes, compared with the vivo embryos (P < 0.01). In vitro-produced embryos supplemented with 50 ng or 100 ng HSC70 had higher expression of HSPA1A, HSC70, Bcl-2, and Bax genes, compared with the control group (P < 0.01). Embryos supplemented with 100 ng had greater expression of the HSPA8 gene compared with the control group and the group supplemented with 50 ng. However, embryos supplemented with 50 ng had better characteristics (i.e., stage of development and quality) than the control and 100-ng groups. In conclusion, supplementation of in vitro culture medium with HSC70 promoted development to the blastocyst stage and improved blastocyst quality.

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