Exp Clin Endocrinol Diabetes 2007; 115 - OR08_2
DOI: 10.1055/s-2007-972246

Krüppel-like factor 4, a transcription factor highly expressed in male postmeiotic germ cells, is dispensable for spermiogenesis in the mouse

R Behr 1, M Godmann 2, JP Katz 3, KH Kaestner 4
  • 1Deutsches Primatenzentrum Göttingen, Forschergruppe Stammzellen, Göttingen, Germany
  • 2Institut für Anatomie des Universitätsklinikums Essen, Entwicklungsbiologie, Essen, Germany
  • 3University of Pennsylvania, School of Medicine, Department of Medicine, Gastroenterology Division, Philadelphia, United States of America
  • 4University of Pennsylvania School of Medicine, Department of Genetics, Philadelphia, United States of America

Krüppel-like factor 4 (Klf4, GKLF) is a zinc finger transription factor which is essential for postnatal survival in the mouse (1). Klf4 plays an important role for terminal differentiation of keratinocytes, epithelial cells of the tongue (1) and goblet cells in the colon (2). Moreover, Klf4 is aberrantly expressed in some types of tumors such as breast, gastric and colon cancer. Recently, Klf4 has been shown to be an important regulator of the developmental potency of pluripotent cells (3, 4).

We have shown that Klf4 mRNA is strongly expressed in postmeiotic germ cell of the mouse testis (5) suggesting a role for Klf4 also during spermiogenesis. In order to analyze the function of Klf4 in spermatids we deleted the Klf4-gene specifically in germ cells using the Cre-loxP system. Cre-expression in germ cells was driven by the TNAP-Cre mouse strain (6) and the Klf4-loxP allele has been described (2). Homologous recombination of the Klf4 locus was confirmed by genomic southern blotting and the absence of the protein in germ cells was demonstrated by western blotting and immunofluorescence.

Although Klf4 shows very strong expression in spermatids, its deletion did not impair spermiogenesis. Histologically, the mutant testes appeared normal and the mice were fertile. Also, expression of markers for spermiogenesis such as CREM was normal. Ultrastructural analyses using transmission electron microscopy also did not reveal morphological abnormalities in germ cells. In order to identify genes that were regulated by Klf4 in male germ cells we performed microarray analyses using a whole genome array and found genes to be affected known to play roles during spermiogenesis such as Kif17. However, in summary, Klf4 is dispensable for spermiogenesis.

1. Segre JA et al. 1999 Nat Genet 22:356–60

2. Katz JP et al. 2002 Development 129:2619–28

3. Li Y et al. 2005 Blood 105:635–7

4. Takahashi K, Yamanaka S 2006 Cell 126:663–76

5. Behr R, Kaestner KH 2002 Mech Dev 115:167–9

6. Lomeli H et al. 2000 Genesis 26:116–7