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Li H, Cong X, Yu W, Jiang Z, Fu K, Cao R, Tian W, Feng Y. Baicalin inhibits oxidative injures of mouse uterine tissue induced by acute heat stress through activating the Keap1/Nrf2 signaling pathway. Res Vet Sci 2022; 152:717-725. [PMID: 36270181 DOI: 10.1016/j.rvsc.2022.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 09/16/2022] [Accepted: 10/06/2022] [Indexed: 11/05/2022]
Abstract
Heat stress effect the physiological functions of body, and reproductive system is one of the most sensitive. It's imperative to find out suitable measures to alleviate harmful effects of heat stress. Baicalin is well-known with its antioxidative property. To examine whether Baicalin could reduce oxidative injures of uterine tissue in heat-stressed mice. The mice were divided into four groups: control (Con), Baicalin (Bai), heat stress (H) and heat stress plus Baicalin (H + Bai). The oxidative damage of uterine tissue was detected by ELISA, H&E staining, tunnel assay and immunohistochemical staining. The protein/mRNA expressions of Keap1/Nrf2 related factors were detected by Western blot or QPCR. The results showed that mice heat-stressed at 41 °C for 2 h induced macroscopic changes, significantly increased MDA content and reduced activities of antioxidant enzymes including SOD, CAT and GSH-Px of the uterine tissue. Compared with Con group, heat stress up-regulated caspase-3 and caspase-9, enhanced the apoptosis of endometrial epithelial and glandular epithelial cells, improved the HO-1 mRNA/protein and NQO1 protein expressions, while down-regulated the mRNA/protein of Keap1. Compared with H group, antioxidant enzyme activities, Nrf2 protein and Nrf2, NQO1 and GCLC mRNA expressions were significantly increased in the H + Bai group. While the uterine epithelial cells apoptosis, MDA contents, caspase-3, caspase-9 and Keap1 protein and HO-1 mRNA expressions were decreased in the H + Bai group of mice compared with that in H group. Briefly, acute heat stress causes oxidative injures and apoptosis of mouse uterine tissue and Baicalin protects uterine tissue from the damages possibly through Keap1/Nrf2 signaling pathway.
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Affiliation(s)
- Huatao Li
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, 266109 Qingdao, China
| | - Xia Cong
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, 266109 Qingdao, China
| | - Wenhui Yu
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, 266109 Qingdao, China
| | - Zhongling Jiang
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, 266109 Qingdao, China
| | - Kaiqiang Fu
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, 266109 Qingdao, China
| | - Rongfeng Cao
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, 266109 Qingdao, China
| | - Wenru Tian
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, 266109 Qingdao, China.
| | - Yanni Feng
- Laboratory of Animal Reproductive Physiology and Disease, College of Veterinary Medicine, Qingdao Agricultural University, 266109 Qingdao, China.
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Lapyuneyong N, Tangsrisakda N, Choowong-In P, Chaisiwamongkol K, Uabundit N, Sawatpanich T, Arun S, Wu ATH, Iamsaard S. Seed extract of Thai Mucuna pruriens reduced male reproductive damage in rats induced by chronic stress. PHARMACEUTICAL BIOLOGY 2022; 60:374-383. [PMID: 35180038 PMCID: PMC8865108 DOI: 10.1080/13880209.2022.2034896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/11/2022] [Accepted: 01/22/2022] [Indexed: 06/14/2023]
Abstract
CONTEXT Thai Mucuna pruriens (L.) DC. var. pruriens (Fabaceae) (TMP) is known to enrich reproduction but preventive effects on stress related adverse reproductive parameters are not documented. OBJECTIVE This study investigates the protective property of TMP seed extract on reproductive damage under chronic stress (CS). MATERIALS AND METHODS Male Sprague-Dawley rats were divided into four groups. The control and CS groups received distilled water, whereas the pre-treated rats received the aqueous TMP seed extract at doses of 150 and 300 mg/kg BW for 20 days before co-treatments with CS induction (immobilization and forced swimming) for 81 days. Serum was used to determine the cortisol and testosterone levels. Histology of testis and epididymis was observed with localization of androgen receptor (AR). Sperm parameters and the expression of steroidogenic acute regulatory (StAR), cytochrome P450 family 11 subfamily a member 1 (CYP11A1), AR, HSP70, caspases (3 and 9) and tyrosine phosphorylation (TyrPho) proteins were investigated. RESULTS TMP extract improved cortisol level (0.84 ± 0.02 µg/dL) and protected against the damage of reproductive tissues and sperm parameters (count [49.78 ± 3.74 million sperm/mL], viability [90.01 ± 1.17%] and precocious acrosome reaction [1.38 ± 0.48%]). Expression of testicular StAR, CYP11A1, AR and HSP70 proteins was improved. Caspase expression was decreased in treated rats. TMP increased AR expression in CS sperm. Moreover, TyrPho protein expression was corrected after TMP administration. CONCLUSIONS TMP seed protected against adverse reproductive parameters in CS via improvements of functionally testicular markers and reductions of apoptotic proteins. It is possible to develop the TMP beans as an alternative medicine in treating of male subfertility caused by CS.
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Affiliation(s)
- Natthapol Lapyuneyong
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Nareelak Tangsrisakda
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Pannawat Choowong-In
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Kowit Chaisiwamongkol
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Nongnut Uabundit
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Tarinee Sawatpanich
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Supatcharee Arun
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Research Institute for Human High Performance and Health Promotion (HHP & HP), Khon Kaen University, Khon Kaen, Thailand
| | - Alexander Tsang-Hsien Wu
- College of Medical Science and Technology, The PhD Program for Translational Medicine, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Sitthichai Iamsaard
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Research Institute for Human High Performance and Health Promotion (HHP & HP), Khon Kaen University, Khon Kaen, Thailand
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Roth Z, Kressel YZ, Lavon Y, Kalo D, Wolfenson D. Administration of GnRH at Onset of Estrus, Determined by Automatic Activity Monitoring, to Improve Dairy Cow Fertility during the Summer and Autumn. Animals (Basel) 2021; 11:ani11082194. [PMID: 34438650 PMCID: PMC8388439 DOI: 10.3390/ani11082194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/18/2021] [Accepted: 07/21/2021] [Indexed: 11/16/2022] Open
Abstract
We examined gonadotropin-releasing hormone (GnRH) administration at onset of estrus (OE), determined by automatic activity monitoring (AAM), to improve fertility of dairy cows during the summer and autumn. The study was performed on two dairy farms in Israel. The OE was determined by AAM recorded every 2 h, and a single im dose of GnRH analogue was administered shortly after OE. Pregnancy was determined by transrectal palpation, 40 to 45 d after artificial insemination (AI). Conception risk was analyzed by the GLIMMIX procedure of SAS. Brief visual observation of behavioral estrus indicated that about three-quarters of the events (n = 40) of visually detected OE occurred within 6 h of AAM-detected OE. Accordingly, the GnRH analogue was administered within 5 h of AAM-detected OE, to overlap with the expected endogenous preovulatory LH surge. Overall, pregnancy per AI (P/AI) was monitored over the entire experimental period (summer and autumn) in 233 first, second or third AI (116 and 117 AI for treated and control groups, respectively). Least square means of P/AI for treated (45.8%) and control (39.4%) groups did not differ, but group-by-season interaction tended to differ (p = 0.07), indicating no effect of treatment in the summer and a marked effect of GnRH treatment (n = 58 AI) compared to controls (n = 59 AI) on P/AI in the autumn (56.6% vs. 28.5%, p < 0.03). During the autumn, GnRH-treated mature cows (second or more lactations), and postpartum cows exhibiting metabolic and uterine diseases, tended to have much larger P/AI than their control counterparts (p = 0.07-0.08). No effect of treatment was recorded in the autumn in first parity cows or in uninfected, healthy cows. In conclusion, administration of GnRH within 5 h of AAM-determined OE improved conception risk in cows during the autumn, particularly in those exhibiting uterine or metabolic diseases postpartum and in mature cows. Incorporation of the proposed GnRH treatment shortly after AAM-detected OE into a synchronization program is suggested, to improve fertility of positively responding subpopulations of cows.
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Affiliation(s)
- Zvi Roth
- Department of Animal Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot 76100, Israel; (Z.R.); (Y.Z.K.); (D.K.)
| | - Yaron Z. Kressel
- Department of Animal Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot 76100, Israel; (Z.R.); (Y.Z.K.); (D.K.)
| | - Yaniv Lavon
- Israel Cattle Breeders Association, Caesarea 38900, Israel;
| | - Dorit Kalo
- Department of Animal Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot 76100, Israel; (Z.R.); (Y.Z.K.); (D.K.)
| | - David Wolfenson
- Department of Animal Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot 76100, Israel; (Z.R.); (Y.Z.K.); (D.K.)
- Correspondence: ; Tel.: +972-54-8820700
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Hansen PJ. Prospects for gene introgression or gene editing as a strategy for reduction of the impact of heat stress on production and reproduction in cattle. Theriogenology 2020; 154:190-202. [PMID: 32622199 DOI: 10.1016/j.theriogenology.2020.05.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/06/2020] [Accepted: 05/08/2020] [Indexed: 12/28/2022]
Abstract
In cattle, genetic variation exists in regulation of body temperature and stabilization of cellular function during heat stress. There are opportunities to reduce the impact of heat stress on cattle production by identifying the causative mutations responsible for genetic variation in thermotolerance and transferring specific alleles that confer thermotolerance to breeds not adapted to hot climates. An example of a mutation conferring superior ability to regulate body temperature is the group of frame-sift mutations in the prolactin receptor gene (PRLR) that lead to a truncated receptor and development of cattle with a short, sleek hair coat. Slick mutations in PRLR have been found in several extant breeds derived from criollo cattle. The slick mutation in Senepol cattle has been introgressed into dairy cattle in Puerto Rico, Florida and New Zealand. An example of a mutation that confers cellular protection against elevated body temperature is a deletion mutation in the promoter region of a heat shock protein 70 gene called HSPA1L. Inheritance of the mutation results in amplification of the transcriptional response of HSPA1L to heat shock and increased cell survival. The case of PRLR provides a promising example of the efficacy of the genetic approach outlined in this paper. Identification of other mutations conferring thermotolerance at the whole-animal or cellular level will lead to additional opportunities for using genetic solutions to reduce the impact of heat stress.
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Affiliation(s)
- Peter J Hansen
- Department of Animal Sciences, D.H Barron Reproductive and Perinatal Biology Research Program, and Genetics Institute, University of Florida, Gainesville, FL, 32611-0910, USA.
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5
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Morenikeji OB, Ajayi OO, Peters SO, Mujibi FD, De Donato M, Thomas BN, Imumorin IG. RNA-seq profiling of skin in temperate and tropical cattle. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2020; 62:141-158. [PMID: 32292922 PMCID: PMC7142279 DOI: 10.5187/jast.2020.62.2.141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 12/09/2019] [Accepted: 01/03/2020] [Indexed: 11/20/2022]
Abstract
Skin is a major thermoregulatory organ in the body controlling homeothermy, a critical function for climate adaptation. We compared genes expressed between tropical- and temperate-adapted cattle to better understand genes involved in climate adaptation and hence thermoregulation. We profiled the skin of representative tropical and temperate cattle using RNA-seq. A total of 214,754,759 reads were generated and assembled into 72,993,478 reads and were mapped to unique regions in the bovine genome. Gene coverage of unique regions of the reference genome showed that of 24,616 genes, only 13,130 genes (53.34%) displayed more than one count per million reads for at least two libraries and were considered suitable for downstream analyses. Our results revealed that of 255 genes expressed differentially, 98 genes were upregulated in tropically-adapted White Fulani (WF; Bos indicus) and 157 genes were down regulated in WF compared to Angus, AG (Bos taurus). Fifteen pathways were identified from the differential gene sets through gene ontology and pathway analyses. These include the significantly enriched melanin metabolic process, proteinaceous extracellular matrix, inflammatory response, defense response, calcium ion binding and response to wounding. Quantitative PCR was used to validate six representative genes which are associated with skin thermoregulation and epithelia dysfunction (mean correlation 0.92; p < 0.001). Our results contribute to identifying genes and understanding molecular mechanisms of skin thermoregulation that may influence strategic genomic selection in cattle to withstand climate adaptation, microbial invasion and mechanical damage.
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Affiliation(s)
- Olanrewaju B Morenikeji
- Department of Animal Production and Health, Federal University of Technology, Akure, Nigeria.,Department of Biomedical Sciences, Rochester Institute of Technology, Rochester, NY, USA.,Animal Genetics and Genomics Laboratory, Office of International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Oyeyemi O Ajayi
- Animal Genetics and Genomics Laboratory, Office of International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA.,Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Nigeria
| | - Sunday O Peters
- Department of Animal Science, Berry College, Mount Berry, GA 30149, USA
| | | | - Marcos De Donato
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Queretaro 76130, Mexico
| | - Bolaji N Thomas
- Department of Biomedical Sciences, Rochester Institute of Technology, Rochester, NY, USA
| | - Ikhide G Imumorin
- Animal Genetics and Genomics Laboratory, Office of International Programs, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA.,African Institute of Bioscience Research and Training, Ibadan, Nigeria.,Department of Biological Sciences, First Technical University, Ibadan, Nigeria.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
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6
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Lonergan P, Sánchez JM, Mathew DJ, Passaro C, Fair T. Embryo development in cattle and interactions with the reproductive tract. Reprod Fertil Dev 2019; 31:118-125. [PMID: 32188547 DOI: 10.1071/rd18409] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Embryo mortality is a major contributor to poor reproductive efficiency and profitability in cattle production systems. Coordinated interaction between the developing embryo or conceptus and the maternal reproductive tract is essential for pregnancy establishment in mammals. Up to the blastocyst stage, the embryo can grow in the absence of contact with the oviduct or uterus; however, conceptus elongation after hatching and before implantation, a characteristic of ruminant early development, is entirely maternally driven and is essential to ensure that sufficient quantities of interferon-τ (IFNT) are secreted by the developing conceptus to abrogate the mechanisms that bring about luteolysis. Surprisingly, many questions, such as the threshold level of IFNT required for pregnancy maintenance, remain unanswered. Failure of the conceptus to elongate undoubtedly results in embryonic loss and is thus believed to contribute greatly to reproductive failure in cattle.
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Affiliation(s)
- P Lonergan
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 N2E, Dublin 4, Ireland
| | - José María Sánchez
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 N2E, Dublin 4, Ireland
| | - Daniel J Mathew
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 N2E, Dublin 4, Ireland
| | - Claudia Passaro
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 N2E, Dublin 4, Ireland
| | - Trudee Fair
- School of Agriculture and Food Science, University College Dublin, Belfield, D04 N2E, Dublin 4, Ireland
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7
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Zolini AM, Ortiz WG, Estrada-Cortes E, Ortega MS, Dikmen S, Sosa F, Giordano JO, Hansen PJ. Interactions of human chorionic gonadotropin with genotype and parity on fertility responses of lactating dairy cows. J Dairy Sci 2018; 102:846-856. [PMID: 30447974 DOI: 10.3168/jds.2018-15358] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/25/2018] [Indexed: 11/19/2022]
Abstract
Fertility-promoting effects of treatment of lactating dairy cattle with human chorionic gonadotropin (hCG) after artificial insemination (AI) have been variable. Here, we tested whether fertility response to hCG in lactating Holstein cows interacts with genotype and parity. Primiparous (n = 538) and multiparous (n = 613) cows were treated with hCG (3,300 IU) or vehicle 5 d after AI. Pregnancy was diagnosed on d 32 and 60 after AI. A subset of cows (n = 593-701) was genotyped for 4 single nucleotide polymorphisms (SNP) previously associated with fertility. Treatment with hCG increased progesterone concentration on d 12 after AI regardless of genotype or parity. Pregnancy per AI was improved by hCG in primiparous cows but not in multiparous cows. Moreover, hCG treatment interacted with a SNP in coenzyme Q9 (COQ9) to affect fertility. Fertility of cows treated with vehicle was greatest for the AA allele, whereas fertility was lowest for the same genotype among cows treated with hCG. Pregnancy per AI was also affected by genotype for heat shock protein A1-like (HSPA1L) and progesterone receptor (PGR), but no interactions were observed with treatment. Genotype for a SNP in prostate androgen-regulated mucin-like protein 1 (PARM1) was not associated with fertility. Overall, results show that variation in response to hCG treatment on fertility depends on parity and interacts with a SNP in COQ9.
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Affiliation(s)
- A M Zolini
- Department of Animal Sciences, D.H. Barron Reproductive and Perinatal Biology Research Program, and Genetics Institute, University of Florida, Gainesville 32611-0910
| | - W G Ortiz
- Department of Animal Sciences, D.H. Barron Reproductive and Perinatal Biology Research Program, and Genetics Institute, University of Florida, Gainesville 32611-0910
| | - E Estrada-Cortes
- Department of Animal Sciences, D.H. Barron Reproductive and Perinatal Biology Research Program, and Genetics Institute, University of Florida, Gainesville 32611-0910
| | - M S Ortega
- Department of Animal Sciences, D.H. Barron Reproductive and Perinatal Biology Research Program, and Genetics Institute, University of Florida, Gainesville 32611-0910
| | - S Dikmen
- Faculty of Veterinary Medicine, Department of Animal Science, University of Uludag, Bursa, 16059, Turkey
| | - F Sosa
- Department of Animal Science, Cornell University, Ithaca, NY 14853
| | - J O Giordano
- Department of Animal Science, Cornell University, Ithaca, NY 14853
| | - P J Hansen
- Department of Animal Sciences, D.H. Barron Reproductive and Perinatal Biology Research Program, and Genetics Institute, University of Florida, Gainesville 32611-0910.
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Sánchez JM, Mathew DJ, Passaro C, Fair T, Lonergan P. Embryonic maternal interaction in cattle and its relationship with fertility. Reprod Domest Anim 2018; 53 Suppl 2:20-27. [PMID: 30238655 DOI: 10.1111/rda.13297] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/19/2018] [Accepted: 07/23/2018] [Indexed: 11/30/2022]
Abstract
Embryo mortality is a major contributor to poor reproductive efficiency and profitability in cattle production systems. While conception is achieved (i.e., the oocyte is fertilized) in the vast majority of cases if insemination is carried out correctly, a significant proportion of the resulting embryos fail to develop to term. Appropriate communication between the developing conceptus and the maternal endometrium is essential for the establishment and maintenance of pregnancy in all mammals. Up to the blastocyst stage, around Days 7-9, contact worth the female reproductive system is not required. However, the process of conceptus elongation after hatching and prior to implantation is entirely maternally driven and is essential to ensure that sufficient quantities of interferon-tau (IFNT) are secreted by the developing conceptus to abrogate the mechanisms that bring about luteolysis. While the importance of conceptus-derived IFNT in maternal recognition of pregnancy and prevention of luteolysis in cattle is unequivocal, many questions, such as the threshold level of IFNT required for pregnancy maintenance, remain unanswered. Furthermore, the precise role of IFNT-independent mechanisms in pregnancy establishment remains to be elucidated. Irrespective of this, failure of the conceptus to elongate undoubtedly results in embryonic loss and is thus believed to contribute greatly to reproductive failure in cattle. This review will address some of these answered questions and try to shed some light on those gaps in knowledge that could potentially contribute to improved embryo survival and reproductive efficiency.
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Affiliation(s)
- José María Sánchez
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Daniel J Mathew
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Claudia Passaro
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Trudee Fair
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Pat Lonergan
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
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Abstract
Summer heat stress decreases the pregnancy rate in cattle and has been thought to be associated with the early embryonic death caused by the elevation of maternal body temperature. In vitro cultures have been widely used for the evaluation of effects of heat stress on oocytes, fertilization, preimplantation, and embryonic development. Susceptibility to heat stress is present in developmental stages from oocytes to cleavage-stage (before embryonic gene activation, EGA) embryos, leading to a consequent decrease in developmental competence. On the other hand, advanced-stage embryos such as morula or blastocysts have acquired thermotolerance. The mechanism for the developmental stage-dependent change in thermotolerance is considered to be the accumulation of antioxidants in embryos in response to heat-inducible production of reactive oxygen species. The supplementation of antioxidants to the culture media has been known to neutralize the detrimental effects of heat stress. Besides, EGA could be involved in acquisition of thermotolerance in later stages of embryos. Morulae or blastocysts can repair heat-induced unfolded proteins or prevent DNA damage occurring in processes such as apoptosis. Therefore, embryo transfer (ET) that can bypass the heat-sensitive stage could be a good solution to improve the pregnancy rate under heat stress. However, frozen-thawed ET could not improve the pregnancy rate as expected. Frozen-thawed blastocysts were more sensitive to heat stress and showed less proliferation upon heat exposure, compared to fresh blastocysts. Therefore, further research is required to improve the reduction in pregnancy rates due to summer heat stress.
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Affiliation(s)
- Miki Sakatani
- Livestock and Grassland Research Division, Kyushu Okinawa Agricultural Research Center, NARO, Kumamoto 861-1192, Japan
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10
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Effect of cryopreservation technique and season on the survival of in vitro produced cattle embryos. Anim Reprod Sci 2015; 164:162-8. [PMID: 26679433 DOI: 10.1016/j.anireprosci.2015.11.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 11/26/2015] [Accepted: 11/30/2015] [Indexed: 12/31/2022]
Abstract
Embryo cryopreservation is a major tool for conservation and propagation of genetically superior animals. However, it adversely affects the survival of embryos. The objective of this study was to determine the effects of cryopreservation technique (vitrification compared with slow freezing) and different seasons in which oocytes were obtained on the post-warming survival of in vitro produced (IVP) cattle morulae. In experiment 1, morulae (Day 6 post-IVF), obtained from abattoir-sourced oocytes during spring, summer, fall and winter over a period of 3.5 years, were subjected to either vitrification (n=271 morulae), slow freezing (n=281 morulae) or no freezing (control; n=249 morulae). After warming, the morulae were cultured to the expanded blastocyst stage (Day 8 post-IVF). Data were compared using Glimmix procedure in SAS(®). Blastocyst rate differed (P<0.05) among the treatments: unfrozen control (78±3.6%), vitrification (52±4.6%) and slow freezing (35±4.2%). The re-expansion of vitrified morulae upon warming was not correlated with subsequent blastocyst rate (r=-0.048; P>0.05). The morulae produced during fall season had lesser (P<0.05) cleavage and morula rates (67±1.6%; Day 2 post-IVF and 22±1.4%; Day 6 post-IVF, respectively) than all other seasons (74±1.1 and 30±1.2%, respectively). Blastocyst rate was the least (P<0.05) when oocytes were collected during the summer season in both control and slowly frozen groups. Blastocyst development rate did not change due to season in vitrification group (P>0.05). In conclusion, vitrification is a more desirable technique than slow freezing for cryopreservation of IVP cattle morulae. If the slow freezing method is employed, greater success can be achieved using oocytes collected in the winter and spring with a primary contributing factor being lesser morulae development if oocytes are collected in the fall and also the lesser blastocyst formation of cryopreserved morulae when oocytes are collected in the summer.
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