| In the present study, the PSS-I and PSS-II genes, and possibly a third, novel PSS gene in tilapia were cloned and sequenced from tilapia and primers for RT-PCR were designed. Pancreatic islet tissues (Brockmann bodies) were harvested from tilapia and transplanted under the renal capsules of STZ-diabetic nude mice. Mice with functioning grafts underwent graft nephrectomies at 1, 7, 14, 28, or 56 days post transplant. Expression of PSS-I and PSS-II mRNA in explanted grafts were compared to expression in donor Brockmann bodies using RT-PCR. In addition, electron microscopy was used to try to assess whether the mechanism of loss of SST-28+ delta cells is via apoptosis or degranulation. The entire sequence of the SST-II cDNA and the majority of the SST-I cDNA have been determined. In addition, a portion of cDNA has been cloned that is similar to an SST-III cDNA sequence found in closely related fish species. (Abstract shortened by UMI.)... |
