Profiling trefoil factor family (TFF) expression in the mouse: identification of an antisense TFF1-related transcript in the kidney and liver.

The expression of the trefoil factor family (TFF) genes (TFF1, TFF2, and TFF3) was systematically analyzed in 18 different organs from male or female mice using RT-PCR analysis. The expression patterns showed some gender-specific differences, e.g., TFF3 transcripts in the urinary bladder and liver. Furthermore, the murine expression profile differed from that in human, e.g., in the respiratory tract and uterine cervix. As a hallmark, an aberrant TFF1-related transcript was detected specifically in the kidney and liver of several mouse strains. Molecular characterization of this rare 1.8kb long transcript from the kidney clearly revealed that its 3' region originated from the antisense strand of the TFF1 locus containing particularly large parts of the antisense strands of introns 1 and 2. Homology searches using various databases revealed that this antisense TFF1-related transcript is subject of intense alternative splicing and no protein product encoded by this antisense TFF1-related transcript could be identified. Although the function of this transcript is not known currently, we can speculate that this antisense TFF1-related transcript might have a gene silencing effect particularly on TFF1 expression in the murine kidney and liver.