Dynamics of The Expression of Pluripotency and Lineage Specific Genes in The Pre and Peri-Implantation Goat Embryo.

OBJECTIVE

Two critical points of early development are the first and second lineage segregations, which are regulated by a wide spectrum of molecular and cellular factors. Gene regulatory networks, are one of the important components which handle inner cell mass (ICM) and trophectoderm (TE) fates and the pluripotency status across different mammalian species. Considering the importance of goats in agriculture and biotechnology, this study set out to investigate the dynamics of expression of the core pluripotency markers at the mRNA and protein levels.

MATERIALS AND METHODS

In this experimental study, the expression pattern of three pluripotency markers (, and ) and the linage specific markers (, and ) were quantitatively assessed in matured (MII) oocytes and embryos at three distinctive stages: 8-16 cell stage, day-7 (D7) blastocysts and D14 blastocysts. Moreover, expression of , , proteins, and their localization in the goat blastocyst was observed through immunocytochemistry.

RESULTS

Relative levels of mRNA transcripts for Nanog and in D3 (8-16 cell) embryos were significantly higher than D7 blastocysts and mature oocytes, while was only significantly higher than D7 blastocysts. However, the expression pattern of , as an epiblast linage marker, decreased from the oocyte to the D14 stage. The expression pattern of and , as extra embryonic linage markers, also showed a similar trend from oocyte to D3 while their expressions were up-regulated in D14 blastocysts.

CONCLUSION

Reduction in , , mRNA transcription and a late increase in extra embryonic linage markers suggests that the developmental program of linage differentiation is retarded in goat embryos compared to previously reported data on mice and humans. This is likely related to late the implantation in goats.