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Updated: Jun 24, 2026
08:43
Loss- and Gain-of-function Approach to Investigate Early Cell Fate Determinants in Preimplantation Mouse Embryos
Published on: June 6, 2016
Cyclin T2 is essential for mouse embryogenesis.
Jiri Kohoutek1, Qintong Li, Dalibor Blazek
1Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic. kohoutek@vri.cz
Molecular and Cellular Biology
|April 15, 2009
Summary
Cyclin T2 (CycT2) is crucial for embryonic development, not redundant with Cyclin T1 (CycT1). Inactivating the CycT2 gene leads to early embryonic lethality, highlighting distinct gene regulation by P-TEFb complexes.
Area of Science:
- Molecular Biology
- Developmental Biology
- Genetics
Background:
- The positive transcription elongation factor b (P-TEFb) complex, comprising cyclin T (CycT) and cyclin-dependent kinase 9 (Cdk9), is vital for RNA polymerase II transcription elongation.
- Mammalian P-TEFb exists with either Cyclin T1 (CycT1) or Cyclin T2 (CycT2), raising questions about their functional redundancy.
Purpose of the Study:
- To investigate whether CycT1 and CycT2 have redundant functions or regulate distinct gene sets.
- To determine the role of CycT2 in embryonic development through genetic inactivation.
Main Methods:
- Genetic inactivation of the CycT2 gene (Ccnt2) in mice using beta-galactosidase-neomycin (beta-geo) gene trap technology.
- Visualization of beta-galactosidase expression during mouse embryogenesis and in adult tissues.
- Assessment of CycT2 function in embryonic stem cells using short interfering RNAs (siRNAs).
Main Results:
- CycT2 exhibits widespread expression during embryogenesis and in all adult tissues and organs.
- Homozygous inactivation of CycT2 (CycT2-/-) resulted in early embryonic lethality, with no viable offspring.
- siRNA-mediated knockdown of CycT2 in embryonic stem cells indicated downregulation of critical genes.
Conclusions:
- CycT1 and CycT2 are not functionally redundant.
- Distinct P-TEFb complexes formed by CycT1 and CycT2 regulate separate subsets of genes essential for embryonic development.
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