Fruiting-body formation in S. aurantiaca, and phylogenetic tree of Myxococcales. (a) Comparison of fruiting-body formation with (from top to bottom) blue (450 nm), red (700 nm) and far-red (750 nm) light illumination. Cell concentration is expressed in Klett Units (KU). (b) Phylogenetic comparison of Myxococcales indicating strains coding for BphPs with an asterisk (the number of asterisks indicates the number of BphPs) and photoactive yellow protein (PYP) with arrows. The side bar highlights three different suborders of Myxococcales: Cystobacterineae (light gray), Nanocystineae (dark gray) and Sorangineae (black). BphPs and PYPs are found in select species within all three suborders of Myxobacteria; the number and type of photoreceptors present varies between species.