{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T16:25:40Z","timestamp":1791044740286,"version":"4.1.0"},"reference-count":51,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2025,7,3]],"date-time":"2025-07-03T00:00:00Z","timestamp":1751500800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>The asynchrony of cytoplasmic and nuclear maturation in cumulus\u2013oocyte complexes (COCs) due to prematurely declining concentrations of cyclic adenosine monophosphate (cAMP) has been shown to result in reduced oocyte developmental competence. The objective of this study was to evaluate the effect of pre-IVM treatment with cAMP modulators for different durations on the developmental potential of equine oocytes used for cloned embryo production. Collected COCs were transferred to cryovials filled with transport medium at 20\u201322 \u00b0C. Within the cryovials, the COCs were either untreated (Control) for 18 h or treated with 50 \u00b5M forskolin and 100 \u00b5M 3-isobutyl-1-methylxanthine for the first 4 h (Pre-IVM 4 h) or the entire 18 h (Pre-IVM 18 h). Oocytes were then transferred to maturation medium and incubated for a further 22\u201324 h at 38.5 \u00b0C in 5% CO2 in air. Somatic cell nuclear transfer embryos were then produced using the meiotically mature oocytes and donor cells from six different fibroblast cell lines. The rates of maturation and embryo development did not differ significantly between the groups, though blastocyst formation tended to be inferior in the Pre-IVM 4 h group compared with the Control group (p = 0.06). Of 67 blastocysts produced, 23 were transferred to recipient mares on Day 4 or 5 post-ovulation. Regarding the pregnancy outcomes, no significant differences were found between the groups, and four viable foals were born, each derived from a different donor cell line. The findings expand on those from previous evaluations of this biphasic IVM system, and indicate that the cAMP-modulating treatments exert limited effects under the pre-IVM conditions used here.<\/jats:p>","DOI":"10.3390\/ani15131961","type":"journal-article","created":{"date-parts":[[2025,7,3]],"date-time":"2025-07-03T09:57:39Z","timestamp":1751536659000},"page":"1961","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Effect of Pre-IVM Duration with cAMP Modulators on the Production of Cloned Equine Embryos and Foals"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-1881-6772","authenticated-orcid":false,"given":"Jenin V.","family":"Cortez","sequence":"first","affiliation":[{"name":"Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camden, NSW 2570, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kylie","family":"Hardwicke","sequence":"additional","affiliation":[{"name":"Catalina Equine Reproduction Centre, North Richmond, NSW 2754, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlos E.","family":"M\u00e9ndez-Calder\u00f3n","sequence":"additional","affiliation":[{"name":"Catalina Equine Reproduction Centre, North Richmond, NSW 2754, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8352-0404","authenticated-orcid":false,"given":"Christopher G.","family":"Grupen","sequence":"additional","affiliation":[{"name":"Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camden, NSW 2570, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"102981","DOI":"10.1016\/j.jevs.2020.102981","article-title":"Current reproductive technologies impacting equine embryo production","volume":"89","author":"Squires","year":"2020","journal-title":"J. Equine Vet. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.anireprosci.2006.10.011","article-title":"Developmental competence of equine oocytes and embryos obtained by in vitro procedures ranging from in vitro maturation and ICSI to embryo culture, cryopreservation and somatic cell nuclear transfer","volume":"98","author":"Galli","year":"2007","journal-title":"Anim. Reprod. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1016\/j.theriogenology.2006.09.027","article-title":"Oocyte maturation: Emerging concepts and technologies to improve developmental potential in vitro","volume":"67","author":"Gilchrist","year":"2007","journal-title":"Theriogenology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1111\/rda.13259","article-title":"Assisted reproductive techniques in mares","volume":"53","author":"Hinrichs","year":"2018","journal-title":"Reprod. Domest. Anim."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1071\/RD10225","article-title":"Recent insights into oocyte-follicle cell interactions provide opportunities for the development of new approaches to in vitro maturation","volume":"23","author":"Gilchrist","year":"2011","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1262\/jrd.2016-016","article-title":"Porcine oocyte maturation in vitro: Role of cAMP and oocyte-secreted factors\u2014a practical approach","volume":"62","author":"Appeltant","year":"2016","journal-title":"J. Reprod. Dev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/j.theriogenology.2012.09.020","article-title":"Regulation of sheep oocyte maturation using cAMP modulators","volume":"79","author":"Rose","year":"2013","journal-title":"Theriogenology"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"566","DOI":"10.1002\/mrd.21175","article-title":"Regulation of the G2\/M transition in rodent oocytes","volume":"77","author":"Downs","year":"2010","journal-title":"Mol. Reprod. Dev."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1093\/biolre\/ioab176","article-title":"Approaches to oocyte meiotic arrest in vitro and impact on oocyte developmental competence","volume":"106","author":"Richani","year":"2022","journal-title":"Biol. Reprod."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2999","DOI":"10.1093\/humrep\/deq246","article-title":"Simulated physiological oocyte maturation (SPOM): A novel in vitro maturation system that substantially improves embryo yield and pregnancy outcomes","volume":"25","author":"Albuz","year":"2010","journal-title":"Hum. Reprod."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Bernal-Ulloa, S.M., Heinzmann, J., Herrmann, D., Hadeler, K.G., Aldag, P., Winkler, S., Pache, D., Baulain, U., Lucas-Hahn, A., and Niemann, H. (2016). Cyclic AMP affects oocyte maturation and embryo development in prepubertal and adult cattle. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0150264"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"810","DOI":"10.1093\/humrep\/dew020","article-title":"Extending prematuration with cAMP modulators enhances the cumulus contribution to oocyte antioxidant defence and oocyte quality via gap junctions","volume":"31","author":"Li","year":"2016","journal-title":"Hum. Reprod."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/j.theriogenology.2021.06.003","article-title":"Simulated physiological oocyte maturation (SPOM) improves developmental competence of in vitro produced goat embryos","volume":"172","author":"Suresh","year":"2021","journal-title":"Theriogenology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1012","DOI":"10.1071\/RD19249","article-title":"Conditions to optimise the developmental competence of immature equine oocytes","volume":"32","author":"Metcalf","year":"2020","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Zeng, H.T., Richani, D., Sutton-McDowall, M.L., Ren, Z., Smitz, J.E., Stokes, Y., Gilchrist, R.B., and Thompson, J.G. (2014). Prematuration with cyclic adenosine monophosphate modulators alters cumulus cell and oocyte metabolism and enhances developmental competence of in vitro-matured mouse oocytes. Biol. Reprod., 91.","DOI":"10.1095\/biolreprod.114.118471"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.theriogenology.2022.05.023","article-title":"The Simulated Physiological Oocyte Maturation (SPOM) system in domestic animals: A systematic review","volume":"188","author":"Leal","year":"2022","journal-title":"Theriogenology"},{"key":"ref_17","unstructured":"NHMRC (2013). Australian Code for the Care and Use of Animals for Scientific Purposes."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1530\/jrf.0.0890573","article-title":"Effect of oxygen concentration on in-vitro development of preimplantation sheep and cattle embryos","volume":"89","author":"Thompson","year":"1990","journal-title":"J. Reprod. Fertil."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.theriogenology.2023.03.018","article-title":"Cloning horses by somatic cell nuclear transfer: Effects of oocyte source on development to foaling","volume":"203","author":"Cortez","year":"2023","journal-title":"Theriogenology"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.jevs.2016.04.048","article-title":"The effect of a simulated physiological oocyte maturation system on the in vitro production of equine embryos","volume":"41","author":"Metcalf","year":"2016","journal-title":"J. Equine Vet. Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1758","DOI":"10.1071\/RD19257","article-title":"Morphology, developmental stages and quality parameters of in vitro-produced equine embryos","volume":"31","author":"Carnevale","year":"2019","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1016\/S0303-7207(01)00686-4","article-title":"Role of cyclic nucleotide signaling in oocyte maturation","volume":"187","author":"Conti","year":"2002","journal-title":"Mol. Cell. Endocrinol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"548","DOI":"10.1095\/biolreprod.103.021204","article-title":"Bovine cumulus cell-oocyte gap junctional communication during in vitro maturation in response to manipulation of cell-specific cyclic adenosine 3\u2032,5\u2032-monophosophate levels","volume":"70","author":"Thomas","year":"2004","journal-title":"Biol. Reprod."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"504","DOI":"10.1093\/humrep\/dem344","article-title":"Effects of cilostamide and forskolin on the meiotic resumption and embryonic development of immature human oocytes","volume":"23","author":"Shu","year":"2008","journal-title":"Hum. Reprod."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"651","DOI":"10.1002\/mrd.21186","article-title":"The equine oocyte: Factors affecting meiotic and developmental competence","volume":"77","author":"Hinrichs","year":"2010","journal-title":"Mol. Reprod. Dev."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"712","DOI":"10.1111\/evj.12839","article-title":"The development of in vitro embryo production in the horse","volume":"50","author":"Morris","year":"2018","journal-title":"Equine Vet. J."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1017\/S0967199406003534","article-title":"Blastocyst development in equine oocytes with low meiotic competence after suppression of meiosis with roscovitine prior to in vitro maturation","volume":"14","author":"Choi","year":"2006","journal-title":"Zygote"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Ezoe, K., Yabuuchi, A., Tani, T., Mori, C., Miki, T., Takayama, Y., Beyhan, Z., Kato, Y., Okuno, T., and Kobayashi, T. (2015). Developmental competence of vitrified-warmed bovine oocytes at the germinal-vesicle stage is improved by cyclic adenosine monophosphate modulators during in vitro maturation. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0126801"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.theriogenology.2014.07.042","article-title":"Evaluation of the simulated physiological oocyte maturation system for improving bovine in vitro embryo production","volume":"83","author":"Guimaraes","year":"2015","journal-title":"Theriogenology"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"634","DOI":"10.1071\/AN17895","article-title":"Evaluation of the simulated physiological oocyte maturation (SPOM) system on F1 Gyr \u00d7 Holstein oocytes and embryos","volume":"59","author":"Leal","year":"2018","journal-title":"Anim. Prod. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1007\/s10815-018-1365-4","article-title":"Simulated physiological oocyte maturation has side effects on bovine oocytes and embryos","volume":"36","author":"Razza","year":"2019","journal-title":"J. Assist. Reprod. Genet."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1002\/mrd.22307","article-title":"Pre-maturation with cAMP modulators in conjunction with EGF-like peptides during in vitro maturation enhances mouse oocyte developmental competence","volume":"81","author":"Richani","year":"2014","journal-title":"Mol. Reprod. Dev."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.anireprosci.2014.12.012","article-title":"cAMP modulation during sheep in vitro oocyte maturation delays progression of meiosis without affecting oocyte parthenogenetic developmental competence","volume":"154","author":"Buell","year":"2015","journal-title":"Anim. Reprod. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1071\/RD12341","article-title":"Reversible meiotic arrest in feline oocytes","volume":"26","author":"Herrick","year":"2014","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"740","DOI":"10.1017\/S0967199417000636","article-title":"Delaying meiotic resumption during transportation of bovine cumulus-oocyte complexes: Effects on development, apoptosis and caspases activity of in vitro-produced embryos","volume":"25","author":"Leao","year":"2017","journal-title":"Zygote"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1016\/j.theriogenology.2020.09.024","article-title":"The SPOM-adapted IVM system improves in vitro production of bovine embryos","volume":"158","author":"Leal","year":"2020","journal-title":"Theriogenology"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1016\/j.jevs.2013.10.128","article-title":"Holding equine oocytes at room temperature for 18 hours prior to in vitro maturation maintains their developmental competence","volume":"34","author":"Galli","year":"2014","journal-title":"J. Equine Vet. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"102990","DOI":"10.1016\/j.jevs.2020.102990","article-title":"Advances in holding and cryopreservation of equine oocytes and embryos","volume":"89","author":"Hinrichs","year":"2020","journal-title":"J. Equine Vet. Sci."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1016\/j.cveq.2006.07.004","article-title":"Equine cloning","volume":"22","author":"Hinrichs","year":"2006","journal-title":"Vet. Clin. N. Am. Equine Pract."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1071\/RD05130","article-title":"Equine cloning: Applications and outcomes","volume":"18","author":"Vanderwall","year":"2006","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"R75","DOI":"10.1530\/REP-22-0124","article-title":"Omne vivum ex ovo: The oocyte reprogramming and remodeling activities","volume":"165","author":"Fulka","year":"2023","journal-title":"Reproduction"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/j.theriogenology.2016.04.021","article-title":"Epigenetic reprogramming in mammalian species after SCNT-based cloning","volume":"86","author":"Niemann","year":"2016","journal-title":"Theriogenology"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Olivera, R., Moro, L.N., Jordan, R., Luzzani, C., Miriuka, S., Radrizzani, M., Donadeu, F.X., and Vichera, G. (2016). In vitro and in vivo development of horse cloned embryos generated with iPSCs, mesenchymal stromal cells and fetal or adult fibroblasts as nuclear donors. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0164049"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1904","DOI":"10.1071\/RD19294","article-title":"In vitro-produced horse embryos exhibit a very narrow window of acceptable recipient mare uterine synchrony compared with in vivo-derived embryos","volume":"31","author":"Claes","year":"2019","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"103097","DOI":"10.1016\/j.jevs.2020.103097","article-title":"Laboratory production of equine embryos","volume":"89","author":"Lazzari","year":"2020","journal-title":"J. Equine Vet. Sci."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1071\/RD22224","article-title":"Equine in vitro produced blastocysts: Relationship of embryo morphology, stage and speed of development to foaling rate","volume":"35","author":"Lewis","year":"2023","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1007\/s43032-020-00249-9","article-title":"Effect of age and morphology on live birth rate after cleavage stage embryo transfer","volume":"28","author":"Awadalla","year":"2021","journal-title":"Reprod. Sci."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1016\/j.theriogenology.2019.06.020","article-title":"The recipient\u2019s day after ovulation and the number of corpora lutea influence the likelihood of pregnancy in mares following transfer of ICSI frozen embryos","volume":"135","author":"Claes","year":"2019","journal-title":"Theriogenology"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"965","DOI":"10.1016\/S0093-691X(00)00405-2","article-title":"Factors affecting pregnancy rates and early embryonic death after equine embryo transfer","volume":"54","author":"Carnevale","year":"2000","journal-title":"Theriogenology"},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Donato, G.G., Necchi, D., Vandaele, H., Vita, M.E., Bertero, A., Vincenti, L., and Nervo, T. (2023). Influence of intrauterine fluid detection, number of transfers and age of the recipient on pregnancy rate and early embryonic loss in a commercial embryo transfer program. Animals, 13.","DOI":"10.3390\/ani13111799"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"104641","DOI":"10.1016\/j.jevs.2023.104641","article-title":"Pre-maturation of oocytes for equine cloning using cAMP modulators","volume":"125","author":"Cortez","year":"2023","journal-title":"J. Equine Vet. Sci."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/13\/1961\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:04:07Z","timestamp":1760033047000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/13\/1961"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7,3]]},"references-count":51,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["ani15131961"],"URL":"https:\/\/doi.org\/10.3390\/ani15131961","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,7,3]]}}}