Fig. 1.

Mouse intraflagellar transport 81 (IFT81) was highly expressed in the testis and developmentally regulated during spermatogenesis. A: analysis of relative Ift81 mRNA expression in adult mouse tissues by RT-PCR (a) and quantitative PCR (b). Ift81 mRNA expression levels were normalized by 18S rRNA. Notice that the specific Ift81 mRNA was detected in all tissues examined, and the signal was the strongest in the testis. B: analysis of mouse IFT81 protein expression by Western blot using the less sensitive Pico system. Notice that IFT81 was only detected in testes. C: analysis of mouse IFT81 protein expression in multiple tissues by Western blot using the more sensitive Femto system. Notice that besides in the testis, the full-length IFT81 was also expressed in brain, lung, and kidney. The antibody also cross-reacted with a 50-kDa protein in liver and 2 smaller proteins (48 and 50 kDa) in kidney. Fifty micrograms of total protein was loaded in all tissues except testis. Only 10 μg of total testicular protein was loaded. D: IFT81 expression during the 1st wave of spermatogenesis. A representative Western blot result from 3 independent experiments shows that IFT81 protein was expressed from day 8 after birth, and the level was significantly increased from day 16 after birth.