Cre recombinase activity specific to postnatal, premeiotic male germ cells in transgenic mice

Genesis. 2008 Dec;46(12):738-42. doi: 10.1002/dvg.20437.


We have generated a transgenic mouse line,Tg(Stra8-cre)1Reb (Stra8-cre), which expresses improved Cre recombinase under the control of a 1.4 Kb promoter region of the germ cell-specific stimulated by retinoic acid gene 8 (Stra8). cre is expressed only in males beginning at postnatal day (P)3 in early-stage spermatogonia and is detected through preleptotene-stage spermatocytes. To further define when cre becomes active, we crossed Stra8-cre males with Tg(ACTB-Bgeo/GFP)21Lbe (Z/EG) reporter females and compared the expression of enhanced green fluorescent protein (EGFP) with the protein encoded by the zinc finger and BTB domain containing 16 (Zbtb16) gene, PLZF-a marker for undifferentiated spermatogonia. Co-expression of EGFP is observed in the majority of PLZF+ cells. We also tested recombination efficiency by mating Stra8-cre;Z/EG males and females with wild-type mice and examining EGFP expression in the offspring. Recombination is detected in >95% of Z/EG+ pups born to Stra8-cre;Z/EG fathers but in none of the offspring born to transgenic mothers, a verification that cre is not functional in females. The postnatal, premeiotic, male germ cell-specific activity of Stra8-cre makes this mouse line a unique resource to study testicular germ cell development.

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Cell Differentiation / genetics
  • Cells, Cultured
  • Embryo, Mammalian
  • Female
  • Genes, Reporter / genetics
  • Integrases / metabolism*
  • Male
  • Mice
  • Mice, Transgenic
  • Promoter Regions, Genetic*
  • Proteins / metabolism
  • Recombination, Genetic / genetics
  • Spermatocytes / growth & development*
  • Spermatogenesis / genetics*


  • Adaptor Proteins, Signal Transducing
  • Proteins
  • Stra8 protein, mouse
  • Cre recombinase
  • Integrases