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Tough beginnings: alterations in the transcriptome of cloned embryos during the first two cell cycles

Rita Vassena1, Zhiming Han, Shaorong Gao

  • 1The Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA.

Developmental Biology
|January 20, 2007
PubMed

Insights

Somatic cell nuclear transfer (SCNT) cloned embryos show abnormal gene expression due to incomplete nuclear reprogramming. Key affected genes involve transcription, impacting various cellular functions and maternal mRNA populations.

Area of Science:

  • Developmental Biology
  • Reproductive Biology
  • Genomics

Background:

  • Somatic cell nuclear transfer (SCNT) is a technique used to create cloned embryos.
  • SCNT-derived embryos often exhibit abnormal phenotypes compared to fertilized embryos.
  • These abnormalities suggest defects in nuclear reprogramming by the recipient ooplasm.

Purpose of the Study:

  • To investigate the extent and timing of nuclear reprogramming in SCNT embryos.
  • To analyze the transcriptome of mouse SCNT embryos during early development.

Main Methods:

  • Microarray analysis was employed to study gene expression.
  • Transcriptome profiling was performed on SCNT embryos during the first two cell cycles.

Main Results:

  • A significant number of genes were found to be mis-expressed in SCNT embryos.
  • Genes regulating transcription were prominently affected, suggesting reprogramming challenges.
  • Widespread alterations were observed in maternal mRNA populations.

Conclusions:

  • Gene expression in early SCNT embryos is significantly abnormal.
  • Incomplete reprogramming of transcription factor genes contributes to these abnormalities.
  • Defects in reprogramming impact multiple cellular functions, including oxidative phosphorylation and mRNA processing.

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