Fig. 1.
Adenovirus-mediated gene transfer into male germ cells. (A and B) Histological appearance of testes injected with AxCANLacZ at 7 days (A) or 4 weeks (B) after birth. Whole mounts of testes were stained 1 month after virus injection. (C–H) In vitro infection of immature testis cells (C and D), GS cells (E and F), and mGS cells (G and H) by AxCANEGFP. The cells were exposed to adenovirus overnight at 2.5 × 105 pfu/ml (C and D) or 1.8 × 105 pfu/ml (E–H), and EGFP fluorescence was examined 6 h (D) or 1 day (F and H) after infection. (I) Flow-cytometric analysis of immature testis cells 2 days after transduction of AxCANEGFP at 2.5 × 105 pfu/ml. EpCAM-positive spermatogonia cells showed EGFP fluorescence. Black line, control Ig; red line, specific antibody. (J) Flow-cytometric analysis of GS cells 3 days after transduction of AxCANEGFP. The values are mean ± SEM (n = 3). (K) Increase in GS cell number after adenovirus infection. After overnight infection, GS cells were cultured for 6 days. The values are mean ± SEM (n = 4). Although no significant difference in cell number was found at 6.0 × 103 pfu/ml, GS cell growth was inhibited at higher virus concentrations (P < 0.05 by t test). (L) The intensity of EGFP signals decreased during a 17-day culture. The cells were infected at 2.5 × 105 pfu/ml and passaged twice during this period. (Scale bars: 50 μm for A and B and 100 μm for C–H.)