The in-vitro block to development and initiation of transcription in early equine embryos

Autor: S. P. Brinsko, J. E. Ellington, W. B. Currie, G. G. Ignotz, Barry A. Ball, P. G. A. Thomas, P. G. Miller
Rok vydání: 2010
Předmět:
Zdroj: Equine Veterinary Journal. 25:87-90
ISSN: 2042-3306
0425-1644
Popis: Summary Coculture of early cleavage-stage equine embryos with other cell types, primarily oviductal epithelial cells, can support development to blastocysts in vitro. Embryos cultured in complex medium without cellular support develop at a significantly poorer rate and appear to undergo a developmental block in vitro. In 2 experiments, 1–8-cell embryos (n = 15) were cultured in Ham's F12: Dulbecco's MEM for 5 days or until morphological degeneration occurred. Embryos were assessed for stage of development and quality score on a daily basis. At the end of culture, embryos were stained to determine the number of nuclei present or were fixed and sectioned for evaluation by light microscopy. Additional embryos (n = 8) collected on Days 2–7 after ovulation were labelled with [3H]uridine and incorporation was determined by autoradiography. Of 15 embryos cultured without cellular support, 3 reached the morula stage and the remaining 12 embryos cleaved to the 8–16-cell stage before undergoing morphological degeneration. [3H]uridine was incorporated into embryos at the 8-cell stage or later, but no incorporation was detected in embryos at the 4-cell stage. These results indicate that early equine embryos appear to undergo a developmental block in vitro at the 8–16-cell stage, relief of which is temporally associated with the onset of embryonic transcription.
Databáze: OpenAIRE
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