Previous Article | Next Article ![]()
Molecular and Cellular Biology, June 2009, p. 3280-3285, Vol. 29, No. 12
0270-7306/09/$08.00+0 doi:10.1128/MCB.00172-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
,
Qintong Li,2,
Dalibor Blazek,2
Zeping Luo,2
Huimin Jiang,2 and
B. Matija Peterlin2
Veterinary Research Institute, Hudcova 70, Brno, 621 00, Czech Republic,1 Departments of Medicine, Microbiology, and Immunology, Rosalind Russell Medical Research Center, University of California at San Francisco, San Francisco, California 94143-07032
Received 5 February 2009/ Returned for modification 7 March 2009/ Accepted 29 March 2009
The positive transcription elongation factor b (P-TEFb) is essential for the elongation of transcription and cotranscriptional processing by RNA polymerase II. In mammals, it contains predominantly the C-type cyclin cyclin T1 (CycT1) or CycT2 and cyclin-dependent kinase 9 (Cdk9). To determine if these cyclins have redundant functions or affect distinct sets of genes, we genetically inactivated the CycT2 gene (Ccnt2) using the β-galactosidase-neomycin gene (β-geo) gene trap technology in the mouse. Visualizing β-galactosidase during mouse embryogenesis revealed that CycT2 is expressed abundantly during embryogenesis and throughout the organism in the adult. This finding was reflected in the expression of CycT2 in all adult tissues and organs. However, despite numerous matings of heterozygous mice, we observed no CycT2–/– embryos, pups, or adult mice. This early lethality could have resulted from decreased expression of critical genes, which were revealed by short interfering RNAs against CycT2 in embryonic stem cells. Thus, CycT1 and CycT2 are not redundant, and these different P-TEFb complexes regulate subsets of distinct genes that are important for embryonic development.
Published ahead of print on 13 April 2009.
Supplemental material for this article may be found at http://mcb.asm.org/.
J.K. and Q.L. contributed equally.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»