Heat shock protein 70 gene expression in equine blastocysts after exposure of oocytes to high temperatures in vitro or in vivo after exercise of donor mares.
Abstract: Heat above homeothermy can be detrimental to embryonic development, and cells may produce heat shock proteins to try to mitigate these effects. The authors examined the developmental competence of equine oocytes after a single heat exposure (42 degrees C, 2 or 4 h) during early or late stages of in vitro maturation. Rates of nuclear maturation, cleavage after intracytoplasmic sperm injection, and advanced embryonic development (morula or blastocyst) were compared to those for unexposed controls. Concentrations of heat shock protein 70 (HSPA1A) mRNA were determined by real-time RT-PCR in resulting blastocysts, and were compared to those for embryos derived in vivo from control or exercised mares. Exposure of oocytes to heat at the onset of in vitro maturation did not affect any measured end point. However, exposure to 42 degrees C late in maturation culture reduced rates of oocyte nuclear maturation for both the 2 h (43/105 (43%) compared to control 70/103 (68%); P < 0.01), and 4 h (47/106 (44%) compared to control 60/103 (59%); P < 0.05) groups. Additionally, late heat exposure reduced development to morulae and blastocyst stages after intracytoplasmic sperm injection (ICSI; 18/89 (20%) compared to control 43/128 (34%); P < 0.05). Seven days after oocyte heat exposure, resultant blastocysts had a higher abundance of HSPA1A gene transcripts, relative to those for 18S rRNA. In vitro-produced embryos and lower-quality in vivo-produced embryos had significantly higher relative HSPA1A mRNA (lower 18S rRNA) concentrations than did higher-quality in vivo-produced embryos. The authors concluded that equine oocytes were sensitive to heat during late in vitro maturation, and responded to thermal shock with an increased ratio of HSPA1A:18S gene expression that was measurable in the resulting blastocyst. Embryos produced in vitro (including controls) had increased levels of HSPA1A mRNA relative to 18S rRNA compared to in vivo-produced embryos, suggesting a response to environmental insult.
Copyright 2010 Elsevier Inc. All rights reserved.
Publication Date: 2010-04-22 PubMed ID: 20416934DOI: 10.1016/j.theriogenology.2010.02.020Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research studies how heat exposure affects the development of horse embryos (equine oocytes), focusing on a specific protein (heat shock protein 70). The heat is detrimental to embryonic development, and the paper explores the specific effects of heat on different stages of maturation. The research finds that late-stage embryos are more sensitive to heat and respond by producing more heat shock protein.
Methodology and Results
- The study tested the development of horse embryos when exposed to high temperatures at the early and late stages of maturation. Heat exposure was accomplished both in vitro (in a lab environment) and in vivo (inside live horses).
- The researchers conducted three tests: the first measures the rate of nuclear maturation; the second tests cleavage after fertilization; the third assesses advanced embryonic development. They compared all these tests with unexposed controls.
- Results showed that heat exposure at the beginning of maturation did not affect the development of the embryos. However, late heat exposure significantly reduced the maturation and further development of embryos.
Role of Heat Shock Protein 70 (HSPA1A)
- The researchers assessed the levels of HSPA1A in the resulting embryos through RT-PCR, a technique to amplify and quantify targeted DNA molecules.
- Seven days after heat exposure, researchers found that resulting embryos had a higher amount of HSPA1A, relative to other checks (18S rRNA). This increase suggests that the embryo was responding to thermal shock by producing more of the heat shock protein.
- Embryos produced in a lab environment had higher levels of HSPA1A compared to those developed naturally inside horses. This suggests that the in vitro environment caused some form of stress to the embryos, resulting in the increased production of HSPA1A.
Conclusions of the Study
- The study concluded that late-stage horse embryos are more sensitive to heat. These embryos respond to thermal shock by increasing the production of HSPA1A.
- The increase in HSPA1A in in vitro-produced embryos indicates that the lab environment might present a stress to the embryos.
Cite This Article
APA
Mortensen CJ, Choi YH, Ing NH, Kraemer DC, Vogelsang MM, Hinrichs K.
(2010).
Heat shock protein 70 gene expression in equine blastocysts after exposure of oocytes to high temperatures in vitro or in vivo after exercise of donor mares.
Theriogenology, 74(3), 374-383.
https://doi.org/10.1016/j.theriogenology.2010.02.020 Publication
Researcher Affiliations
- Department of Animal Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843-2471, USA. cmortensen@ufl.edu
MeSH Terms
- Animals
- Blastocyst / metabolism
- Embryonic Development
- Gene Expression Regulation, Developmental
- HSP70 Heat-Shock Proteins / genetics
- HSP70 Heat-Shock Proteins / metabolism
- Heat-Shock Response
- Horses / embryology
- Horses / genetics
- Horses / metabolism
- Hot Temperature
- Meiosis
- Oocytes / metabolism
- Physical Conditioning, Animal
- RNA, Messenger / metabolism
- RNA, Ribosomal, 18S / metabolism
Citations
This article has been cited 6 times.- Lee SH, Sun MH, Jiang WJ, Li XH, Heo G, Zhou D, Chen Z, Cui XS. Alpha-lipoic acid attenuates heat stress-induced apoptosis via upregulating the heat shock response in porcine parthenotes. Sci Rep 2023 May 24;13(1):8427.
- Liu QX, Zhang W, Wang J, Hou W, Wang YP. A proteomic approach reveals the differential protein expression in Drosophila melanogaster treated with red ginseng extract (Panax ginseng). J Ginseng Res 2018 Jul;42(3):343-351.
- Qi X, Li H, Cong X, Wang X, Jiang Z, Cao R, Tian W. Baicalin increases developmental competence of mouse embryos in vitro by inhibiting cellular apoptosis and modulating HSP70 and DNMT expression. J Reprod Dev 2016 Dec 20;62(6):561-569.
- Martino NA, Dell'Aquila ME, Filioli Uranio M, Rutigliano L, Nicassio M, Lacalandra GM, Hinrichs K. Effect of holding equine oocytes in meiosis inhibitor-free medium before in vitro maturation and of holding temperature on meiotic suppression and mitochondrial energy/redox potential. Reprod Biol Endocrinol 2014 Oct 11;12:99.
- Ashraf S, Shah SM, Saini N, Dhanda S, Kumar A, Goud TS, Singh MK, Chauhan MS, Upadhyay RC. Developmental competence and expression pattern of bubaline (Bubalus bubalis) oocytes subjected to elevated temperatures during meiotic maturation in vitro. J Assist Reprod Genet 2014 Oct;31(10):1349-60.
- Sananmuang T, Phutikanit N, Nguyen C, Manee-In S, Techakumphu M, Tharasanit T. In vitro culture of feline embryos increases stress-induced heat shock protein 70 and apoptotic related genes. J Reprod Dev 2013;59(2):180-8.
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