Fig. 4. Partners of RacGAP(84C) encode testis-specific genes. (A) Ethidium bromide-stained agarose gel showing RT-PCR amplified fragments after electrophoretic separation. Lane 1: cdi (498 bp); 2: TMS1d (426 bp); 3: RacGAP(84C) (274 bp); 4: Fragment size marker (Gibco-BRL); 5: Fragment size marker (Invitrogen); 6: Rac1 (856 bp); 7: RacGAP(84C) (274bp); 8: Rac1 amplification without reverse transcriptase (negative control). (B) Northern analysis. Total RNA from: lane 1, 300 isolated testes; lane 2, 200 adult flies and lane 3, 200 isolated ovaries. Detection of cdi transcripts with a ³²P-random-labeled probe shows that the 6.0 kb transcript is specific for testes and the 6.8 kb transcript is specific for ovaries. The third form of 5.7 kb described by Matthews and Crews (Matthews and Crews, 1999) was detected only in total adult RNA after longer exposure of northern blot (not shown). (C) Detection of ß-gal activity in testis from the enhancer trap line cdi^P242. Staining is present in the apical part of the germarium with dividing spermatogonia (arrowhead), and in the distal part where the final stages of differentiation occur (arrow). (D-E) Dissection of testes and seminal vesicles of 5-day-old males. (D) Control w¹¹¹⁸ males have transparent testes (arrow) and seminal vesicles full of sperm (arrowhead). (E) w; Rac1^j11,FRT2A,cdi^R47/Rac1^j11,FRT2A males exhibit an accumulation of dense material in the distal region (arrow) and seminal vesicles full of sperm (arrowhead). (F-G) Isolated testis of Rac1^j11,FRT2A,cdi^R47/Rac1^j11,FRT2A separated from its seminal vesicle. (F) Before crushing, no sperm are detectable (arrows). (G) After crushing, in addition to uncharacterised material, we observe motile sperm issuing from the distal extremity of the testis (arrows).