Growth and development of Dictyostelium discoideum overexpressing manganese superoxide dismutase

Abstract

Dictyostelium discoideum, a soil-dwelling eukaryotic microorganism, encodes a manganese superoxide dismutase named SodM (formerly called SodE). Fluorescence of SodM-GFP fusion protein was detected in mitochondria of D. discoideum, indicating that SodM is a mitochondrialocalizing superoxide dismutase. Expression of sodM was observed throughout the life cycle. Maximum level of gene expression was observed at the aggregation stage. An sodM-overexpressing D. discoideum, sodM^oe, grew faster and reached higher cell density in a liquid medium than did the wild type. Multicellular structures formed by sodM^oe on a non-nutrient agar were larger in size than those formed by the wild type. These results indicate that SodM plays important roles both in growth and development of D. discoideum.