DISRUPTION OF THE POLYKETIDE SYNTHASE 14 FROM THE FOREST SOIL DWELLING DICTYOSTELIUM DISCOIDEUM RESULTS IN A DEFECT IN SLUG FORMATION AND MIGRATIONLAVANYA MUTHUKUMAR, MAULD H. LAMARQUE AND KIRAGANDUR MANJUNATH
Dictyostelium discoideum is an ecologically important forest soil dwelling social amoeba. It consumes bacteria in decaying matter and maintains the bio-ecological balance in forest soil. When their main nutrient source, bacteria, is scarce, Dictyostelium discoideum cells undergo starvation induced development to form dormant spores. Dictyostelium discoideum is one of the largest repositories of an important class of enzymes called Polyketide synthases (PKS) that make the majority of commercially available antibiotics and therapeutics. However, the in vivo role of these PKS enzymes in the Dictyostelium discoideum life cycle and the forest ecology is unknown. In this study the Dictyostelium discoideum type I Polyketide synthase 14 or dipks14 gene was disrupted using gene knockout technology. The effect of the loss of the dipks14 gene on the morphology and behaviour of Dictyostelium discoideum was observed. Functional characterization of dipks14 by gene disruption and phenotyping indicates that the disruption of the dipks14 correlates with the presence of a mix of non-motile normal sized slugs and motile reduced sized slugs that have a migration defect. dipks14 gene disruption slugs are able to form fruiting bodies and viable spores, however the distance between the fruiting bodies is reduced. This suggests a role for dipks14 in maintaining distance between the individual multicellular stages such as the slug and the fruiting body and consequently in uniform spore dispersal and survival of germinating new amoebae ensuring homeostasis of forest soil ecology.