In vitro and in vivo development of mice morulae after storage in non-frozen conditions

Autor: Miriam Pérez-Crespo, Belén Pintado, Alfonso Gutiérrez-Adán, Alfredo Serrano, Juan de Dios Hourcade
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
instname
Reproductive Biology and Endocrinology, Vol 10, Iss 1, p 62 (2012)
Reproductive Biology and Endocrinology : RB&E
Repositorio de Resultados de Investigación del INIA
Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria INIA
INIA: Repositorio de Resultados de Investigación del INIA
Popis: Background Interchange of genetically modified (GM) mice between laboratories using embryos provides several advantages. Not only is transport stress avoided, but also the health status of the recipient colony is not compromised. Embryos do not need to be shipped in frozen stage, which requires expensive packaging in addition to a certain degree of expertise in order to freeze and thaw them correctly. The aim of this study was to examine different storage conditions and their effect on embryo viability in order to establish the feasibility of practical, non-frozen conditions for embryo shipment. Methods Mouse morulae developed in vivo (collected from donors 2.5d post coitum) or in vitro (zygotes cultured until morulae stage) were stored, combining two different media (KSOMeq or KSOM-H) and temperatures (4 degrees C, 15 degrees C and 37 degrees C) throughout 24 or 48 hours. After storage in vitro viability was assessed determining percentage of development to blastocyst and total cell number. In vivo viability was determined based on the number of implantations and living fetuses after embryo transfer of stored embryos. The storage effect at the molecular level was assessed by studying a gene pool involved in early development by quantitative RT-PCR. Results In vivo-produced morulae stored for 24 hours did not show differences in development up to the blastocyst stage, regardless of the storage type. Even though a decrease in the total cell number in vivo was observed, embryo development after embryo transfer was not affected. All 24 hour storage conditions tested provided a similar number of implantations and fetuses at day 14 of pregnancy. Morulae obtained from in vitro embryo culture collected at the 1-cell stage showed a decreased ability to develop to blastocyst after 24 hours of storage at 15degrees C both in KSOMeq and KSOM-H. Concomitantly, a significant decrease of embryo implantation rates after transfer to recipients was also found. In order to further characterize the effect of non-frozen storage combining a molecular approach with the ordinary in vitro culture evaluation, embryos collected at the morula stage were submitted to the same storage conditions described throughout 48 hours. In vitro culture of those embryos showed a significant decrease in their developmental rate to blastocyst in both KSOMeq and KSOM-H at 15degrees C, which also affected the total number of cells. Gene transcription studies confirmed significant alterations in retrotransposons (Erv4 and Iap) after 48 h of storage at 15degrees C. Conclusions Our results show that both KSOMeq and KSOM-H can be equally used, and that several temperature conditions allow good survival rates in vitro and in vivo. Some of these storage conditions can substitute freezing in order to maintain embryo viability for 24–48 hours, providing a reliable and less demanding technical alternative for embryo interchanges.
This work was performed as part of, and financed by, Project AGL2004-00332. JDH received a Ph D. grant from the INIA (Ministry of Science and Innovation). We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its unit of Information Resources for Research (URICI).
Databáze: OpenAIRE