Differentiation in Streptomyces

Differentiation in Streptomyces: The Properties and Programming of Diverse Cell-types
from Keith F. Chater writing in Streptomyces: Molecular Biology and Biotechnology:

Streptomyces colonies are complex differentiated organisms, generated from a single ovoid spore by filamentous growth and branching. Eventually, much of this biomass is converted to large numbers of spores in long chains on specialised aerial hyphae. During colony development, different cellular compartments have different physiology and metabolism, and exoskeletal and cytoskeletal elements bring about different morphological changes. These cellular differentiating processes are underpinned by a large number of regulatory genes, often operating in cascades. During the transition from biomass accumulation to reproductive development, antibiotics are made, sometimes under the control of developmental regulators.

Further reading: Streptomyces: Molecular Biology and Biotechnology