Pheromone produced by the myxobacterium Stigmatella aurantiaca

Area of Science:

• Microbiology
• Cellular signaling
• Developmental biology

Background:

• Stigmatella aurantiaca is a myxobacterium known for complex multicellular development.
• Fruiting body formation in myxobacteria involves intricate signaling pathways.
• The role of extracellular signaling molecules in Stigmatella aurantiaca development requires further elucidation.

Purpose of the Study:

• To identify and characterize extracellular signaling molecules involved in Stigmatella aurantiaca fruiting body formation.
• To investigate the influence of light and cyclic GMP (cGMP) on pheromone activity.
• To determine the chemical nature of the identified pheromone.

Main Methods:

• Extraction and purification of extracellular signaling molecules from Stigmatella aurantiaca cultures.
• Bioassays to assess the effect of the molecule on aggregation period and fruiting body maturation.
• Chemical characterization of the purified pheromone.
• Investigating interactions with light and cGMP.

Main Results:

• An extracellular, diffusible pheromone was identified in Stigmatella aurantiaca.
• The pheromone significantly reduced the aggregation period under both light and dark conditions.
• The pheromone mimicked light in stimulating the maturation of cell aggregates into fruiting bodies.
• Cellular sensitivity to the pheromone was higher in the light, suggesting a synergistic interaction.
• Cooperative interaction between the pheromone and cyclic GMP (cGMP) was observed, further shortening the aggregation period.
• Chemical analysis indicated the pheromone is a low-molecular-weight lipid.

Conclusions:

• A novel lipid pheromone plays a crucial role in regulating the timing and efficiency of Stigmatella aurantiaca fruiting body development.
• Light and cGMP act synergistically with the pheromone to optimize multicellular development.
• The findings provide insights into the complex signaling networks governing myxobacterial morphogenesis.