|
Volume 9, Issue 6 (November 2007) 9, 739–750; 10.1111/j.1745-7262.2007.00339.x
Analysis of the genetic interactions between Cyclin A1, Atm and p53 during spermatogenesis
Nicole Bäumer, Marie-Luise Sandstede, Sven Diederichs, Gabriele Köhler, Carol Readhead, Ping Ji, Feng Zhang, Etmar Bulk, Jörg Gromoll, Wolfgang E Berdel, Hubert Serve and Carsten Müller-Tidow
1.Department of Medicine, Hematology and Oncology, University of Münster, Domagstrasse 3, Münster 48149, Germany
2.Department of Pathology, University of Münster, Domagstrasse 17, Münster 48149, Germany
3.California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA
4.Interdisciplinary Center for Clinical Research, University of Münster, Domagstrasse 3, Münster 48149, Germany
5.Institute of Reproductive Medicine, University of Münster, Domagstrasse 12, Münster 48129, Germany
Correspondence: Dr Carsten Müller-Tidow, Department of Medicine, Hematology and Oncology, University of Münster, Domagkstr. 3, D-48129 Münster, Germany. Fax: +49-251-835-2673. E-mail: muellerc@uni-muenster.de
Received 26 June 2007; Accepted 24 July 2007.
| Abstract |
|
Aim: To analyze the functional interactions of Cyclin with p53 and Atm in spermatogenesis and DNA double-strand break repair.
Methods: Two lines of double knockout mice were generated. Spermatogenesis and double strand break repair mechanisms were analyzed in Cyclin A1 (Ccna1); p53- and Ccna1; Atm-double knockout mice.
Results: The block in spermatogenesis observed in Cyclin A1-/- (Ccna1-/-) testes at the mid-diplotene stage is associated with polynucleated giant cells. We found that Ccna1-deficient testes and especially the giant cells accumulate unrepaired DNA double-strand breaks, as detected by immunohistochemistry for phosphorylated H2AX. In addition, the giant cells escape from apoptosis. The development of giant cells occurred in meiotic prophase I, because testes lacking ATM, which are known to develop spermatogenic arrest earlier than prophase I, do not develop giant cells in the absence of cyclin A1. Cyclin A1 interacted with p53 and phosphorylated p53 in complex with CDK2. Interestingly, p53-deficiency significantly increased the number of giant cells in Ccna1-deficient testes. Gene expression analyses of a panel of DNA repair genes in the mutant testes revealed that none of the genes examined were consistently misregulated in the absence of cyclin A1.
Conclusion: Ccna1-deficiency in spermato-genesis is associated with defects in DNA double-strand break repair, which is enhanced by loss of p53.
Keywords: spermatogenesis, testis, cell cycle, meiosis, DNA double-strand break, giant cell, knockout mice
Full Text |
PDF |
中文摘要 |
|
| |
| Browse: 3230 |
|
