Epigenetic Changes in Equine Embryos after Short-Term Storage at Different Temperatures.
Abstract: In embryos subjected to assisted reproductive techniques, epigenetic modifications may occur that can influence embryonic development and the establishment of pregnancy. In horses, the storage temperature during transport of fresh embryos before transfer is a major concern. The aim of this study was, therefore, to determine the effects of two storage temperatures (5 °C and 20 °C) on equine embryos, collected at day seven after ovulation and stored for 24 h, on: (i) morphological development; (ii) expression of candidate genes associated with embryo growth and development, maternal recognition of pregnancy, methylation and apoptosis, and (iii) gene-specific and global DNA methylation. Embryos (n = 80) were collected on day seven or day eight after ovulation and assigned to four groups: day seven control (E7F, fresh); day seven, stored for 24 h at 5 °C (E5C); day seven, stored for 24 h at 20 °C (E20C) and day eight control (E8F, fresh 24h time control). The embryos and the storage medium (EquiHold, holding medium, Minitube, Tiefenbach, Germany) from all treatment groups were analyzed for (i) medium temperature, pH, and lipid peroxidation (malondialdehyde; MDA) and (ii) embryo morphology, mRNA expression and DNA methylation (immunohistochemistry and gene-specific DNA methylation). The size of embryos stored at 5 °C was larger (p < 0.01), whereas embryos stored at 20 °C were smaller (p < 0.05) after 24 h. There were no changes in pH and MDA accumulation irrespective of the group. The mRNA expression of specific genes related to growth and development (POU5F1, SOX2, NANOG), maternal recognition of pregnancy (CYP19A1, PTGES2), DNA methylation (DNMT1, DNMT3A, DNMT3B) and apoptosis (BAX) in the E5C and E20C were either up or downregulated (p < 0.05) when compared to controls (E7F and E8F). The immune expression of 5mC and 5hmC was similar among treatment groups. Percentage of methylation in the CpG islands was lower in the specific genes ESR1, NANOG and DNMT1 (p < 0.001) in E20C embryos when compared to E8F (advanced embryo stage). Therefore, our study demonstrates for the first time the gene-specific and global DNA methylation status of fresh equine embryos collected on days seven and eight after ovulation. Although our results suggest some beneficial effects of storage at 20 °C in comparison to 5 °C, the short-term storage, regardless of temperature, modified gene expression and methylation of genes involved in embryo development and may compromise embryo viability and development after transfer.
Publication Date: 2021-05-06 PubMed ID: 34066466PubMed Central: PMC8148113DOI: 10.3390/ani11051325Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research investigates how the storage temperature of horse embryos influences their development and the success of pregnancy. The study particularly focuses on the effect of short-term storage at two different temperature (5 °C and 20 °C) on the embryos’ development, gene expression, and DNA methylation.
Objective and Methodology
- The researchers aimed to determine the consequences of storing equine embryos at either 5 °C or 20 °C for 24 hours.
- The evaluation was based on certain factors: their morphological development, the expression of genes associated with embryo growth and development, recognition of pregnancy, DNA methylation, and cellular death (apoptosis).
- 80 embryos were collected on the seventh or eighth day after ovulation and divided into four groups for comparative analysis. Two groups were controls, kept fresh without storage, while the remaining two were stored at the indicated temperatures.
Findings and Analysis
- Embryos stored at 5 °C had increased size, while those stored at 20 °C were smaller after 24 hours.
- No changes were observed in the acidity (pH value) and lipid peroxidation (MDA level, a parameter of oxidative stress) of the storage medium, which were consistent across all groups.
- There were noticeable alterations in the mRNA expression of specific genes linked to growth and development, pregnancy recognition, DNA methylation and apoptosis in embryos that were stored, compared to fresh ones. These modifications varied from upregulation to downregulation.
- The global DNA methylation – modification of DNA that usually represses gene transcription – appeared the same among all groups. However, the methylation percentage at certain specific genes decreased in embryos stored at 20 °C compared to the advanced-stage embryos (Day 8 fresh).
Conclusion
- The research revealed, for the first time, information on gene-specific and global DNA methylation status of fresh equine embryos collected on day seven and eight post-ovulation.
- The results suggest some benefits of storing embryos at 20 °C compared to 5 °C. However, short-term storage at any temperature affected gene expression and methylation related to embryo development and might reduce the success rate of embryo transfer and subsequent development.
Cite This Article
APA
Gastal GDA, Scarlet D, Melchert M, Ertl R, Aurich C.
(2021).
Epigenetic Changes in Equine Embryos after Short-Term Storage at Different Temperatures.
Animals (Basel), 11(5).
https://doi.org/10.3390/ani11051325 Publication
Researcher Affiliations
- Center for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, University of Veterinary Medicine Vienna, 1210 Vienna, Austria.
- Instituto Nacional de Investigación Agropecuaria INIA, Estación Experimental La Estanzuela, Ruta 50 km 11, 39173 Colonia, Uruguay.
- Division of Obstetrics, Gynecology and Andrology, Department for Small Animals and Horses, University of Veterinary Medicine Vienna, 1210 Vienna, Austria.
- Center for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, University of Veterinary Medicine Vienna, 1210 Vienna, Austria.
- Vetcore Facility, University of Veterinary Medicine Vienna, 1210 Vienna, Austria.
- Center for Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, University of Veterinary Medicine Vienna, 1210 Vienna, Austria.
Conflict of Interest Statement
The authors declare no conflict of interest.
References
This article includes 61 references
- Squires E. Current reproductive technologies impacting equine embryo production.. J. Equine Vet. Sci. 2020;89:102981.
- Hinrichs K, Choi Y-H. Equine embryo biopsy, genetic testing, and cryopreservation.. J. Equine Vet. Sci. 2012;32:390–396.
- Foss R, Ortis H, Hinrichs K. Effect of potential oocyte transport protocols on blastocyst rates after intracytoplasmic sperm injection in the horse.. Equine Vet. J. 2013;45:39–43.
- Squires E.L, Carnevale E.M, McCue P.M, Bruemmer J.E. Embryo technologies in the horse.. Theriogenology 2003;59:151–170.
- Watson A.J, Westhusin M.E, de Sousa P.A, Betts D.H, Barcroft L.C. Gene expression regulating blastocyst formation.. Theriogenology 1999;51:117–133.
- Rader K, Choi Y-H, Hinrichs K. Intracytoplasmic sperm injection, embryo culture, and transfer of in vitro–produced blastocysts.. Vet. Clin. Equine Pract. 2016;32:401–413.
- O’Neill C. The epigenetics of embryo development.. Anim. Front. 2015;5:42–49.
- Bird A. DNA methylation patterns and epigenetic memory.. Genes Dev. 2002;16:6–21.
- Jaenisch R, Bird A. Epigenetic regulation of gene expression: How the genome integrates intrinsic and environmental signals.. Nat. Genet. 2003;33:245–254.
- Reik W, Dean W, Walter J. Epigenetic reprogramming in mammalian development.. Science 2001;293:1089–1093.
- Vrooman L.A, Rhon-Calderon E.A, Chao O.Y, Nguyen D.K, Narapareddy L, Dahiya A.K, Putt M.E, Schultz R.M, Bartolomei M.S. Assisted reproductive technologies induce temporally specific placental defects and the preeclampsia risk marker sFLT1 in mouse.. Development 2020;147.
- Schieve L.A, Cohen B, Nannini A, Ferre C, Reynolds M.A, Zhang Z, Jeng G, Macaluso M, Wright V.C. A population-based study of maternal and perinatal outcomes associated with assisted reproductive technology in Massachusetts.. Matern. Child Health J. 2007;11.
- Jacob S, Moley K.H. Gametes and embryo epigenetic reprogramming affect developmental outcome: Implication for assisted reproductive technologies.. Pediatr. Res. 2005;58:437–446.
- Chen Z, Robbins K.M, Wells K.D, Rivera R.M. Large offspring syndrome: A bovine model for the human loss-of-imprinting overgrowth syndrome Beckwith-Wiedemann.. Epigenetics 2013;8:591–601.
- Leese H.J. Metabolism of the preimplantation embryo: 40 years on.. Reproduction 2012;143:417–427.
- McCaw B.A, Stevenson T.J, Lancaster L.T. Epigenetic responses to temperature and climate.. Integr. Comp. Biol. 2020;60:1469–1480.
- Canovas S, Ivanova E, Romar R, García-Martínez S, Soriano-Ubeda C, García-Vázquez F.A, Saadeh H, Andrews S, Kelsey G, Coy P. DNA methylation and gene expression changes derived from assisted reproductive technologies can be decreased by reproductive fluids.. Elife 2017;6:e23670.
- Canovas S, Ross P.J, Kelsey G, Coy P. DNA methylation in embryo development: Epigenetic impact of ART (assisted reproductive technologies). Bioessays 2017;39:1700106.
- Bonometti S, Menarim B.C, Reinholt B.M, Ealy A.D, Johnson S.E. Growth factor modulation of equine trophoblast mitosis and prostaglandin gene expression.. J. Anim. Sci. 2019;97:865–873.
- Breton-Larrivée M, Elder E, McGraw S. DNA methylation, environmental exposures and early embryo development.. Anim. Reprod. 2019;16:465–474.
- Okano M, Bell D.W, Haber D.A, Li E. DNA methyltransferases Dnmt3a and Dnmt3b are essential for de novo methylation and mammalian development.. Cell 1999;99:247–257.
- Li E. Chromatin modification and epigenetic reprogramming in mammalian development.. Nat. Rev. Genet. 2002;3:662–673.
- Suetake I, Shinozaki F, Miyagawa J, Takeshima H, Tajima S. DNMT3L stimulates the DNA methylation activity of Dnmt3a and Dnmt3b through a direct interaction.. J. Biol. Chem. 2004;279:27816–27823.
- Okamoto Y, Yoshida N, Suzuki T, Shimozawa N, Asami M, Matsuda T, Kojima N, Perry A.C.F, Takada T. DNA methylation dynamics in mouse preimplantation embryos revealed by mass spectrometry.. Sci. Rep. 2016;6:1–9.
- Lucas E. Epigenetic effects on the embryo as a result of periconceptional environment and assisted reproduction technology.. Reprod. Biomed. Online. 2013;27:477–485.
- Thompson J.G, Lane M, Gilchrist R.B. Metabolism of the bovine cumulus-oocyte complex and influence on subsequent developmental competence.. Soc. Reprod. Fertil. Suppl. 2007;64:179.
- Urrego R, Rodriguez-Osorio N, Niemann H. Epigenetic disorders and altered gene expression after use of assisted reproductive technologies in domestic cattle.. Epigenetics 2014;9:803–815.
- Poirier M, Smith O.E, Therrien J, Rigoglio N.N, Miglino M.A, Silva L.A, Meirelles F.V, Smith L.C. Resiliency of equid H19 imprint to somatic cell reprogramming by oocyte nuclear transfer and genetically induced pluripotency.. Biol. Reprod. 2020;102:211–219.
- Grant D.M, Macedo A, Toms D, Klein C. Fibrinogen in equine pregnancy as a mediator of cell adhesion, an epigenetic and functional investigation.. Biol. Reprod. 2020;102:170–184.
- Aurich C. Reproductive cycles of horses.. Anim. Reprod. Sci. 2011;124:220–228.
- Aurich J.E, Schönherr U, Hoppe H, Aurich C. Effects of antioxidants on motility and membrane integrity of chilled-stored stallion semen.. Theriogenology 1997;48:185–192.
- McKinnon A.O, Squires E.L. Equine embryo transfer.. Vet. Clin. North Am. Equine Pract. 1988;4:305–333.
- Ayala A, Muñoz M.F, Argüelles S. Lipid peroxidation: Production, metabolism, and signaling mechanisms of malondialdehyde and 4-hydroxy-2-nonenal.. Oxid. Med. Cell. Longev. 2014;2014.
- Beckelmann J, Budik S, Helmreich M, Palm F, Walter I, Aurich C. Sex-dependent insulin like growth factor-1 expression in preattachment equine embryos.. Theriogenology 2013;79:193–199.
- Hackett C.H, Greve L, Novakofski K.D, Fortier L.A. Comparison of gene-specific DNA methylation patterns in equine induced pluripotent stem cell lines with cells derived from equine adult and fetal tissues.. Stem Cells Dev. 2012;21:1803–1811.
- Köhne M, Ille N, Erber R, Razavi M.S.A, Walter I, Aurich C. Effects of periovulatory gonadotrophin treatment on luteal function and endometrial expression of selected genes in cyclic pony mares.. Theriogenology 2016;86:2147–2155.
- Scarlet D, Ille N, Ertl R, Alves B.G, Gastal G.D.A, Paiva S.O, Gastal M.O, Gastal E.L, Aurich C. Glucocorticoid metabolism in equine follicles and oocytes.. Domest. Anim. Endocrinol. 2017;59:11–22.
- Scarlet D, Ertl R, Aurich C, Steinborn R. The orthology clause in the next generation sequencing era: Novel reference genes identified by RNA-seq in humans improve normalization of neonatal equine ovary RT-qPCR data.. PLoS ONE 2015;10:e0142122.
- Kenkel C.D, Aglyamova G, Alamaru A, Bhagooli R, Capper R, Cunning R, deVillers A, Haslun J.A, Hédouin L, Keshavmurthy S. Development of gene expression markers of acute heat-light stress in reef-building corals of the genus Porites.. PLoS ONE 2011;6:e26914.
- Livak K.J, Schmittgen T.D. Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT method.. Methods 2001;25:402–408.
- Heinzmann J, Mattern F, Aldag P, Bernal-Ulloa S.M, Schneider T, Haaf T, Niemann H. Extended in vitro maturation affects gene expression and DNA methylation in bovine oocytes.. Mhr Basic Sci. Reprod. Med. 2015;21:770–782.
- Li L-C, Dahiya R. MethPrimer: Designing primers for methylation PCRs.. Bioinformatics 2002;18:1427–1431.
- Santos F, Dean W. Nuclear Reprogramming.. Springer; Berlin/Heidelberg, Germany 2006. Using immunofluorescence to observe methylation changes in mammalian preimplantation embryos; pp. 129–138.
- Heras S, Smits K, de Schauwer C, van Soom A. Dynamics of 5-methylcytosine and 5-hydroxymethylcytosine during pronuclear development in equine zygotes produced by ICSI.. Epigenetics Chromatin 2017;10:1–13.
- Colchen S, Battut I, Fiéni F, Tainturier D, Siliart B, Bruyas J.F. Quantitative histological analysis of equine embryos at exactly 156 and 168 h after ovulation.. J. Reprod. Fertil. Suppl. 2000;56:527–537.
- Panzani D, Rota A, Marmorini P, Vannozzi I, Camillo F. Retrospective study of factors affecting multiple ovulations, embryo recovery, quality, and diameter in a commercial equine embryo transfer program.. Theriogenology 2014;82:807–814.
- Aurich C, Budik S. Early pregnancy in the horse revisited–does exception prove the rule?. J. Anim. Sci. Biotechnol. 2015;6:1–8.
- Waelchli R.O, MacPhee D.J, Kidder G.M, Betteridge K.J. Evidence for the presence of sodium- and potassium-dependent adenosine triphosphatase α1 and β1 subunit isoforms and their probable role in blastocyst expansion in the preattachment horse conceptus.. Biol. Reprod. 1997;57:630–640.
- Budik S, Walter I, Tschulenk W, Helmreich M, Deichsel K, Pittner F, Aurich C. Significance of aquaporins and sodium potassium ATPase subunits for expansion of the early equine conceptus.. Reproduction 2008;135:497–508.
- Esteves C.L, Sharma R, Dawson L, Taylor S.E, Pearson G, Keen J.A, McDonald K, Aurich C, Donadeu F.X. Expression of putative markers of pluripotency in equine embryonic and adult tissues.. Vet. J. 2014;202:533–535.
- Gagliardi A, Mullin N.P, Ying Tan Z, Colby D, Kousa A.I, Halbritter F, Weiss J.T, Felker A, Bezstarosti K, Favaro R. A direct physical interaction between Nanog and Sox2 regulates embryonic stem cell self-renewal.. EMBO J. 2013;32.
- Herrler A, Krusche C.A, Beier H.M. Insulin and insulin-like growth factor-I promote rabbit blastocyst development and prevent apoptosis.. Biol. Reprod. 1998;59:1302–1310.
- Wang L.M, Feng H.L, Ma Y.Z, Cang M, Li H.J, Yan Z, Zhou P, Wen J.X, Bou S, Liu D.J. Expression of IGF receptors and its ligands in bovine oocytes and preimplantation embryos.. Anim. Reprod. Sci. 2009;114:99–108.
- Alonso C, Bragulat A.F, Llorente J, Morikawa I, von Meyeren M, Losinno L. Pregnancy rates for cooled transported equine embryos according to size and arrival temperature.. J. Equine Vet. Sci. 2020;89:103078.
- Monk M, Boubelik M, Lehnert S. Temporal and regional changes in DNA methylation in the embryonic, extraembryonic and germ cell lineages during mouse embryo development.. Development 1987;99:371–382.
- Edwards J.R, Yarychkivska O, Boulard M, Bestor T.H. DNA methylation and DNA methyltransferases.. Epigenetics Chromatin 2017;10:1–10.
- Marinho L.S.R, Rissi V.B, Lindquist A.G, Seneda M.M, Bordignon V. Acetylation and methylation profiles of H3K27 in porcine embryos cultured in vitro.. Zygote 2017;25:575–582.
- Bestor T.H, Edwards J.R, Boulard M. Notes on the role of dynamic DNA methylation in mammalian development.. Proc. Natl. Acad. Sci. USA 2015;112:6796–6799.
- Young L.E, Sinclair K.D, Wilmut I. Large offspring syndrome in cattle and sheep.. Rev. Reprod. 1998;3:155–163.
- Kleijkers S.H.M, van Montfoort A.P.A, Smits L.J.M, Viechtbauer W, Roseboom T.J, Nelissen E.C.M, Coonen E, Derhaag J.G, Bastings L, Schreurs I.E.L. IVF culture medium affects post-natal weight in humans during the first 2 years of life.. Hum. Reprod. 2014;29:661–669.
- Fernández-Gonzalez R, Moreira P, Bilbao A, Jiménez A, Pérez-Crespo M, Ramírez M.A, de Fonseca F.R, Pintado B, Gutiérrez-Adán A. Long-term effect of in vitro culture of mouse embryos with serum on mRNA expression of imprinting genes, development, and behavior.. Proc. Natl. Acad. Sci. USA 2004;101:5880–5885.
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists