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Updated: Aug 17, 2026

A Reporter Assay to Analyze Intronic microRNA Maturation in Mammalian Cells
06:48

A Reporter Assay to Analyze Intronic microRNA Maturation in Mammalian Cells

Published on: June 16, 2022

Characterization of a highly variable eutherian microRNA gene

Hristo B Houbaviy1, Lucas Dennis, Rudolf Jaenisch

  • 1Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

RNA (New York, N.Y.)
|July 1, 2005
PubMed

Insights

The Early Embryonic microRNA Cluster (EEmiRC) is a recently evolved gene essential for placental mammal development. This rapidly evolving gene is transcribed as a single unit and expressed in trophoblastic stem cells.

Area of Science:

  • Developmental Biology
  • Genomics
  • Molecular Biology

Background:

  • Mouse microRNAs (miRNAs) miR-290-miR295 are encoded by a cluster of partially homologous pre-miRNA hairpins.
  • These miRNAs are likely functionally important in embryonic stem (ES) cells and preimplantation embryos.

Purpose of the Study:

  • To investigate the transcriptional unit and regulatory elements of the Early Embryonic microRNA Cluster (EEmiRC).
  • To analyze the evolutionary origin and functional significance of EEmiRC in mammalian development.

Main Methods:

  • Bioinformatic sequence analysis to identify the EEmiRC transcription unit and promoter elements.
  • Analysis of transcript processing, including Drosha processing.
  • Expression analysis in trophoblastic stem (TS) cells.

Main Results:

  • A spliced, capped, and polyadenylated primary transcript spans the entire EEmiRC.
  • A conserved TATA-box containing promoter element directs EEmiRC transcription.
  • EEmiRC is eutherian-specific, highly variable, and expressed in TS cells.

Conclusions:

  • EEmiRC represents a recently acquired, rapidly evolving gene crucial for eutherian development.
  • Considering the entire miRNA locus organization is vital for understanding evolutionary and functional relationships.

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