scGH's lack of a signal sequence. Similar moities of 16 kDa and 31 kDa were also found in proteins extracted from ocular tissues (neural retina, pigmented epithelium, lens, cornea, choroid) of embryos, although they were not consistently present in vitreous humor. Specific scGH immunoreactivity was also detected in these tissues by immunocytochemistry, but not in axons in the optic fiber layer (OFL) or the optic nerve head (ONH), which were immunoreactive A novel transcript of the growth hormone (GH) gene has been identified in ocular tissues of chick embryos. It is, however, unknown if this transcript (small chicken GH, scGH) is translated. This possibility was therefore assessed. The expression of scGH mRNA was confirmed by RT-PCR, using primers that amplified a 426 bp cDNA of its coding sequence. This cDNA was inserted into an expression plasmid to transfect HEK 293 cells and its translation was shown by specific scGH immunoreactivity in extracts of these cells. This immunoreactivity was directed against the unique N terminus of scGH and was associated with a protein of 16 kDa, comparable with its predicted size. Most of the immunoreactivity detected was, however, associated with a 31 kDa moiety, suggesting scGH is normally dimerized. Neither protein was, however, present in media of the transfected HEK cells, consistent with for full-length GH. In summary, we have established that scGH expression and translation occurs in ocular tissues of chick embryos, in which its localization in the neural retina and the ONH is distinct from that of the full-length protein.