Pluripotency‐associated genes reposition during early embryonic developmental stages in pigs

摘要

We examined the allelic expression and positioning of two pluripotency‐associated genes, and , and two housekeeping genes, and , in 4‐ and 8‐cell porcine embryos utilizing RNA and DNA fluorescence in situ hybridization (FISH) in single blastomeres. The proportion of blastomeres expressing bi‐allelically increased from 45% at the 4‐cell stage to 60% at the 8‐cell stage. Moreover, in 8‐cell embryos, was expressed bi‐allelically in significantly more blastomeres than was the case for , and this was associated with a tendency for alleles to move toward the nuclear interior during 4‐ to 8‐cell transition. However, the radial location of alleles did not change significantly during this transition. The locations of active and inactive alleles based on DNA and RNA FISH signals were also calculated. Inactive alleles were located in very close proximity to the nuclear membrane, whereas active alleles were more centrally disposed in the nucleus. Nevertheless, the nuclear location of active and inactive alleles did not change in either 4‐ or 8‐cell blastomeres. Our RNA and DNA FISH data provide novel information on the allelic expression patterns and positioning of pluripotency‐associated genes, and , during embryonic genome activation in pigs.