Int. J. Dev. Biol. 54: 867 - 875 (2010)

https://doi.org/10.1387/ijdb.092874gk

Vol 54, Issue 5

Dicer is required for Sertoli cell function and survival

Original Article | Published: 18 September 2009

Gwang-Jin Kim^1,2, Ina Georg^1,2, Harry Scherthan³, Matthias Merkenschlager⁴, Florian Guillou⁵, Gerd Scherer*^,1 and Francisco Barrionuevo*^,1

¹Institute of Human Genetics, University of Freiburg, Germany, ²Faculty for Biology, University of Freiburg, Germany, ³Bundeswehr Institute of Radiobiology, Munich, and MPI for Molecular Genetics, Berlin, Germany, ⁴Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College London, UK and ⁵UMR 6175, Physiologie de la Reproduction, INRA-CNRS, Université de Tours, Nouzilly, France

Abstract

Dicer is a key enzyme that processes microRNA precursors into their mature form, enabling them to regulate gene expression. Dicer null mutants die before gastrulation. To study Dicer function in testis development, we crossed mice carrying a conditional Dicer allele with an AMH-Cre transgenic line, thereby inactivating Dicer in Sertoli cells around embryonic day 14.0 (E14.0). Dicer null Sertoli cells show normal embryonic development, and at postnatal day 0 (P0), testis tubules are normal in number and histologically undistinguishable from controls. Subsequently, Dicer-mutant testes show a progressively aberrant development, so that at P6, they contain a reduced number of disorganized testis tubules leading to primary sterility. Apoptosis and prophase I assays reveal a massive wave of apoptosis starting at P3, causing progressive loss of Sertoli cells, but also of germ cells, resulting in drastically reduced testis size. Expression of genes that play crucial roles in testis development, structural integrity and spermatogenesis is downregulated at P0, before morphological changes become apparent, indicating that Dicer-mutant testes are already transcriptionally compromised at this stage. Taken together, the results of this study show that Dicer is required for Sertoli cell function and survival and for spermatogenesis in mice.

Keywords

Dicer, miRNAs, testis, spermatogenesis, sterility