COLOR-CHANGE - A NOVEL BIOMARKER INDICATING SUBLETHAL STRESS IN THE MILLIPEDE JULUS-SCANDINAVIUS (DIPLOPODA)

During investigations on the induction of the 70 kD stress protein fam ily (hsp70, stress-70) in Julus scandinavius following exposure to dif ferent biohazards, the colour of the supernatant of the homogenate was closely correlated to the hsp70 level. Hsp70 has recently been shown to be a suitable biomarker for sublethal toxicity in soil animals. Con trol millipedes typically exhibited red or red-orange supernatants whi lst the supernatant of starved or toxin-exposed diplopods was orange, orange-yellow, or even bright yellow. Based on these observations, a q uantitative colour test was established which was found to be able to indicate the degree of stress situations caused by exposure to heavy m etals (cadmium, zinc), organic pollutants (lindane, PCB 52), or by foo d deprivation in laboratory tests. It is suggested that this is caused by a breakdown of the red-orange bilirubins into orange-yellow urobil ins.