Figure 8. The effect of 9-cis-RA on growth of T. adhaerens fed by Porphyridium cruentum or Chlorella sp.

(A) shows the comparison of the total area and total perimeter of control T. adhaerens and T. adhaerens treated by 9-cis-RA for 24 h expressed as arbitrary units derived from pixel measurements obtained at 24 h and compared to values obtained immediately prior to incubation. The data indicates that animals incubated in 3.3 nM 9-cis-RA decreased their area and perimeter to approximately 50% in comparison to control animals. (B) shows the development of cultures over a three-week period. The animals treated by 9-cis-RA developed a balloon-like phenotype at 72 h of incubation and died at 90 h of incubation. (C and D) show the data obtained with T. adhaerens originating from cultures fed by naturally established biofilms in laboraotory aquariums, fed by Chlorella sp. and treated similarly as shown in (A and B). (E) shows the analysis of circularity of animals presented in (A) and documents that animals treated by 9-cis-RA increased their circularity already at 24 h of exposure suggesting arrest of growth of animal peripheral tissues.