Molecular characterization of genomic activities at the onset of zygotic transcription in mammals

Biol Reprod. 2002 Dec;67(6):1907-18. doi: 10.1095/biolreprod67.6.1907.

Abstract

In rabbit embryos, zygotic transcripts are required for the development of the embryo only from the 8- to 16-cell stage onward, more than 44 h after fertilization (i.e., zygotic gene activation; ZGA). In order to characterize the first zygotic transcripts expressed in this species we used a suppression subtractive hybridization approach to isolate RNA that was present after the major transcriptional activation (morula stage), but absent at the 1-cell stage as maternal transcripts. One hundred fourteen differentially expressed inserts were selected and sequenced. A statistical analysis of expression patterns throughout the preimplantation period of development shows that genes transcribed from ZGA onward follow different patterns of expression. Considering their early post-ZGA behavior, we describe at least two main patterns: a gradual increase from ZGA onward, and a sharp increase in expression at ZGA followed by a marked decrease at the morula stage. Our data show that both ZGA and some early post-ZGA events are involved in the establishment of specific patterns of embryonic gene expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromosomes, Artificial, Bacterial / genetics
  • DNA, Complementary / genetics
  • Embryonic Development
  • Female
  • Gene Expression
  • Gene Library
  • Genome*
  • Male
  • Morula / metabolism
  • Pregnancy
  • RNA / analysis
  • RNA / isolation & purification
  • Rabbits / embryology*
  • Rabbits / genetics*
  • Sequence Analysis, DNA
  • Transcription, Genetic*
  • Zygote / metabolism*

Substances

  • DNA, Complementary
  • RNA