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Intrafollicular Oocyte Transfer (IFOT) of Abattoir-Derived and In Vitro-Matured Oocytes Results in Viable Blastocysts and Birth of Healthy Calves.
Biol Reprod 2015; 92(6):150BR

Abstract

There are still major differences between in vitro production (IVP)-derived and in vivo-derived bovine blastocysts. Therefore, intrafollicular oocyte transfer (IFOT) was used in the present study to allow early embryonic development within the physiological oviductal environment, in order to avoid subsequent harmful effects of the in vitro culture environment. Using modified ovum pickup equipment, in vitro-matured oocytes were transferred into the preovulatory follicle of synchronized heifers (follicular recipients), enabling subsequent ovulation, in vivo fertilization, and in vivo development. When 1646 in vitro-matured oocytes were transferred to 28 follicular recipients, a total of 583 embryos (35.2%) were recovered in excess after uterine flushing at Day 7. Although numbers of generated extra embryos were highly variable, preovulatory follicles with a diameter of 13-14 mm delivered significantly (P < 0.05) larger amounts of extra embryos (34.3 vs. 7.3), as well as extra morulae and blastocysts (8.3 vs. 0.8), compared with follicles with a diameter of 9-10 mm. Nevertheless, the developmental rate to the blastocyst stage was lower in IFOT compared with in vitro-derived control (Vitro) embryos at Day 7 (8.0% vs. 36.5%). Likewise, cumulative developmental rates to the morula or blastocyst stage until Day 7 were lower in IFOT-derived embryos when related to the number of transferred (8.4% vs. 51.7%) or flushed (22.8% vs. 51.7%) embryos. Of the latter, IFOT-derived embryos yielded significantly lower cleavage rates compared with the Vitro controls (63.2% vs. 88.8%), and developmental rate to the morula or blastocyst stage were lower even when related to the proportion of cleaved embryos (36.8% vs. 58.2%). In contrast, lipid content and cryotolerance did not differ between IFOT and fully IVP embryos; but IFOT-derived embryos showed significantly lower lipid content (P < 0.05) and significantly higher cryotolerance compared with IVP-derived embryos cultured in CR1aa medium supplemented with estrus cow serum (ECS), but not when cultured in SOFaa medium supplemented with fatty acid-free BSA (BSA-FFA). Finally, transfer of 19 frozen-thawed IFOT-derived blastocysts to synchronized recipients (uterine recipients) resulted in pregnancy rates comparable with those obtained after transfer of fully in vivo-derived embryos or IVP-derived embryos cultured in SOFaa + BSA-FFA, whereas pregnancy rate following transfer of IVP-derived blastocysts was significantly lower when they were cultured in CR1aa + ECS (42.1% vs. 13.8%). All in all, seven pregnancies presumed to be IFOT derived went to term, and microsatellite analysis confirmed that five calves were indeed derived from IFOT. To our knowledge, these are the first calves born after IFOT in cattle. Interestingly, the average birth weight of IFOT-derived calves was lower than that of IVP-derived calves, even when embryos were cultured in SOFaa + BSA-FFA, indicating that the environment during early embryo development might cause fetal overgrowth. Taken together, for the first time we were able to show that IFOT is a feasible technique to generate bovine blastocysts by transferring in vitro-matured oocytes derived from slaughterhouse ovaries. These IFOT-derived blastocysts closely resemble in vivo-derived blastocysts in terms of lipid content and freeze survival. Thus, the present study laid the groundwork for newly created scientific experiments enabling novel analytical possibilities. Nevertheless, IFOT-derived embryos still reached lower pregnancy rates by trend compared with in vivo-derived embryos, also implicating an important role for the maturational environment in further developmental characteristics.

Authors+Show Affiliations

Unit for Reproductive Medicine, Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany.Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany.Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany.Unit for Reproductive Medicine, Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany.Faculty of Veterinary Medicine, Justus-Liebig-University Giessen, Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals, Giessen, Germany.Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany.Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany.Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany michael.hoelker@itw.uni-bonn.de.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

25926438

Citation

Kassens, Ana, et al. "Intrafollicular Oocyte Transfer (IFOT) of Abattoir-Derived and in Vitro-Matured Oocytes Results in Viable Blastocysts and Birth of Healthy Calves." Biology of Reproduction, vol. 92, no. 6, 2015, p. 150.
Kassens A, Held E, Salilew-Wondim D, et al. Intrafollicular Oocyte Transfer (IFOT) of Abattoir-Derived and In Vitro-Matured Oocytes Results in Viable Blastocysts and Birth of Healthy Calves. Biol Reprod. 2015;92(6):150.
Kassens, A., Held, E., Salilew-Wondim, D., Sieme, H., Wrenzycki, C., Tesfaye, D., ... Hoelker, M. (2015). Intrafollicular Oocyte Transfer (IFOT) of Abattoir-Derived and In Vitro-Matured Oocytes Results in Viable Blastocysts and Birth of Healthy Calves. Biology of Reproduction, 92(6), p. 150. doi:10.1095/biolreprod.114.124883.
Kassens A, et al. Intrafollicular Oocyte Transfer (IFOT) of Abattoir-Derived and in Vitro-Matured Oocytes Results in Viable Blastocysts and Birth of Healthy Calves. Biol Reprod. 2015;92(6):150. PubMed PMID: 25926438.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Intrafollicular Oocyte Transfer (IFOT) of Abattoir-Derived and In Vitro-Matured Oocytes Results in Viable Blastocysts and Birth of Healthy Calves. AU - Kassens,Ana, AU - Held,Eva, AU - Salilew-Wondim,Dessie, AU - Sieme,Harald, AU - Wrenzycki,Christine, AU - Tesfaye,Dawit, AU - Schellander,Karl, AU - Hoelker,Michael, Y1 - 2015/04/29/ PY - 2014/09/05/received PY - 2015/03/25/accepted PY - 2015/5/1/entrez PY - 2015/5/1/pubmed PY - 2016/3/8/medline KW - early development KW - embryo culture KW - follicle KW - in vitro fertilization (IVF) KW - in vitro maturation (IVM) SP - 150 EP - 150 JF - Biology of reproduction JO - Biol. Reprod. VL - 92 IS - 6 N2 - There are still major differences between in vitro production (IVP)-derived and in vivo-derived bovine blastocysts. Therefore, intrafollicular oocyte transfer (IFOT) was used in the present study to allow early embryonic development within the physiological oviductal environment, in order to avoid subsequent harmful effects of the in vitro culture environment. Using modified ovum pickup equipment, in vitro-matured oocytes were transferred into the preovulatory follicle of synchronized heifers (follicular recipients), enabling subsequent ovulation, in vivo fertilization, and in vivo development. When 1646 in vitro-matured oocytes were transferred to 28 follicular recipients, a total of 583 embryos (35.2%) were recovered in excess after uterine flushing at Day 7. Although numbers of generated extra embryos were highly variable, preovulatory follicles with a diameter of 13-14 mm delivered significantly (P < 0.05) larger amounts of extra embryos (34.3 vs. 7.3), as well as extra morulae and blastocysts (8.3 vs. 0.8), compared with follicles with a diameter of 9-10 mm. Nevertheless, the developmental rate to the blastocyst stage was lower in IFOT compared with in vitro-derived control (Vitro) embryos at Day 7 (8.0% vs. 36.5%). Likewise, cumulative developmental rates to the morula or blastocyst stage until Day 7 were lower in IFOT-derived embryos when related to the number of transferred (8.4% vs. 51.7%) or flushed (22.8% vs. 51.7%) embryos. Of the latter, IFOT-derived embryos yielded significantly lower cleavage rates compared with the Vitro controls (63.2% vs. 88.8%), and developmental rate to the morula or blastocyst stage were lower even when related to the proportion of cleaved embryos (36.8% vs. 58.2%). In contrast, lipid content and cryotolerance did not differ between IFOT and fully IVP embryos; but IFOT-derived embryos showed significantly lower lipid content (P < 0.05) and significantly higher cryotolerance compared with IVP-derived embryos cultured in CR1aa medium supplemented with estrus cow serum (ECS), but not when cultured in SOFaa medium supplemented with fatty acid-free BSA (BSA-FFA). Finally, transfer of 19 frozen-thawed IFOT-derived blastocysts to synchronized recipients (uterine recipients) resulted in pregnancy rates comparable with those obtained after transfer of fully in vivo-derived embryos or IVP-derived embryos cultured in SOFaa + BSA-FFA, whereas pregnancy rate following transfer of IVP-derived blastocysts was significantly lower when they were cultured in CR1aa + ECS (42.1% vs. 13.8%). All in all, seven pregnancies presumed to be IFOT derived went to term, and microsatellite analysis confirmed that five calves were indeed derived from IFOT. To our knowledge, these are the first calves born after IFOT in cattle. Interestingly, the average birth weight of IFOT-derived calves was lower than that of IVP-derived calves, even when embryos were cultured in SOFaa + BSA-FFA, indicating that the environment during early embryo development might cause fetal overgrowth. Taken together, for the first time we were able to show that IFOT is a feasible technique to generate bovine blastocysts by transferring in vitro-matured oocytes derived from slaughterhouse ovaries. These IFOT-derived blastocysts closely resemble in vivo-derived blastocysts in terms of lipid content and freeze survival. Thus, the present study laid the groundwork for newly created scientific experiments enabling novel analytical possibilities. Nevertheless, IFOT-derived embryos still reached lower pregnancy rates by trend compared with in vivo-derived embryos, also implicating an important role for the maturational environment in further developmental characteristics. SN - 1529-7268 UR - https://www.unboundmedicine.com/medline/citation/25926438/Intrafollicular_Oocyte_Transfer__IFOT__of_Abattoir_Derived_and_In_Vitro_Matured_Oocytes_Results_in_Viable_Blastocysts_and_Birth_of_Healthy_Calves_ L2 - https://academic.oup.com/biolreprod/article-lookup/doi/10.1095/biolreprod.114.124883 DB - PRIME DP - Unbound Medicine ER -