A transcript corresponding to the gene gbn-1 has been found in Dictyostelium mucoroides during vegetative growth and microcyst development. The nucleotide and amino acid sequence is known, and the amino acid sequence was found to be 65% similar and 50% identical to a hemoglobin protein found in the bacterium Vitreoscilla. The purpose of the study was to further characterize the gbn-1 gene activated during development of microcysts. The transcript was found in Dictostelium cells during the vegetative stage and during microcyst development. Quantitative results, using 18S rRNA as an internal control, on the microcyst cells. Later developing cells still produced the transcript, but in lower amounts. Whether cells were grown submerged under liquid medium or on the surface of a solid medium, the vegetative cells at 48 hours and 56 hours both produced the transcript. Vegetative amoebae from the axenic strain Dictyostelium discodium AX-2 did not produce the gbn-1 transcript. The nutrient source, Escherichia coli, did not contribute to the presence of the gbn-1 transcript. Developing cells exposed to osmotic or metabolic stress by sorbitol or antimycin A showed that the gbn-1 transcript was not included by exposure to these agents. The cells exposed to a different metabolic stress, 2, 4-dinitrophenol, did however induce the gbn-1 transcript
