181. HEPATOCYTE-NUCLEAR FACTOR 3-ALPHA (HNF-3α) EXPRESSION IN THE DEVELOPING PROSTATE OF THE TAMMAR WALLABY: A MARKER OF PROSTATE DIFFERENTIATION

Abstract

The prostate is the source of about 30% of the seminal fluid. The prostate develops from the urogenital sinus involving epithelial-mesenchymal interactions, and is dependent on androgen secretion for its differentiation. Most studies on prostatic development have focused on the mouse but the tammar may be an alternative model for some aspects of prostatic development due to its structural similarity to the human. The tammar prostate is a cone-shaped secretory gland which consists of a central zone, transition zone and peripheral zone, as in humans. In contrast, the mouse prostate is a multi-lobular organ. Although much is known of the hormonal control of prostatic development in the tammar^1,2,3, little is known about the specific markers of its differentiation. HNF-3α is a transcription factor that is expressed in the urogenital epithelium of the prostate in the mouse and human. This study characterised HNF-3α in the developing prostate of the tammar. The full length sequence of the gene was obtained in silico and confirmed by cloning. Tammar HNF-3α is highly conserved, sharing 82% nucleotide identity with the human and 80% nucleotide identity with mouse. We used RT-PCR to examine the temporal expression of HNF-3α, and found that it is expressed throughout prostate development in the male from immediately after birth to day 70, the latest stage examined. It is also expressed in the developing female urogenital sinus during a similar time period. HNF-3α protein has a spatial expression similar to that of the mouse, and it is localised to the nucleus of the urogenital epithelial cells. These results indicate that prostatic differentiation is conserved between the tammar (marsupial) and mouse (eutherian). Characterisation of HNF-3α in the tammar will also provide a useful tool in assessing prostatic differentiation in our ongoing prostatic organ culture experiments.