Shuntarou Oishi Haruka Tsuruoka Miku Nariyama Haruka Nishimura Summary Slime mold naturally avoids chemical substances that it dislikes. We tried to make an evacuation map to test this ability. We found out about how slime mold reacts to chemical substance because we had questions about the nature of slime mold. Introduction Slime molds are single-celled organisms. They are divided into two kinds. They are Physarum and Dictyostelium. Both of them like dark and wet places. Slime molds can move freely. Slime molds avoid citric acid. So we tested using other acids. Experiment 1 Does slime mold spread equally without stimuli? Do slime molds move differently on the outside and the inside? Hypothesis Slime mold spread equally when it gets a stimulus. The outside of slime mold is more expandable than the inside of it. ABC Outside 100% 100% 90% 10% Inside 100% 70% 30% 80% 20% Result They spread equally without stimuli. They didnt spread equally without stimuli. Slime mold spread equally without stimulus. Slime molds dont move differently on the outside and the inside. Inner layer Tube structure of Slime mold Experiment 2 How does slime mold react to each chemical substance? Succinic acid 0.1mol/L Succinic acid 0.5mol/L 1.0mol/L Experimental method Negative hemotaxis Positive chemotaxis For measuring pH Hypothesis Slime mold shows negative chemotaxis. Result negative chemotaxis positive chemotaxis pH Succinic acid 0.1mol/L 1.0mol/L pH6.3 pH5.4 pH5.4 pH4.6 pH4.8 pH4.2 pH4.5 pH4.0 0.5mol/L pH5.9 pH4.9 : 3cm pH4.2 pH4.4 : 2cm : 1cm : 0cm The chemical substance which I used oxalic acid 0.1mol/L, 0.5mol/L, 1.0mol/L We did the same experiment as with succinic acid. But we didnt experiment to examine positive chemotaxis against oxalic acid of 0.5mol/L and 1.0mol/L. Slime mold will show negative chemotaxis. pH6.1 Center One day later Immediately after the experiment Experiment of negative chemotaxis Experiment of positive chemotaxis One day later Immediately after the experiment pH6.6(0.7cm) pH6.9(3.0cm) Slime mold One day later the next day of experiment Experiment of negative chemotaxis pH4.7(1.1cm) slime mold pH4.4(0.8cm) Experiment of negative chemotaxis One day later Immediately after the experiment 2cm the next day of experiment After 5 days of the experiment Four day later Experiment of negative chemotaxis pH4.3(2.0cm) the next day of experiment pH4.1(2cm) pH3.8(0.6cm) pH3.8(0.4cm) we could not find the outside boundary. After 5 days of the experiment negative positive means after the slime mold showed a negative chemotaxis, it showed positive chemotaxis. 0.1mol/L0.5mol/L1.0mol/L Oxalic acid Positive chemotaxis negative positive We think slime mold doesnt have chemotaxis against succinic acid. At first, slime mold made a stop circle because pH of oxalic acid was less than 4. But then, slime mold showed positive chemotaxis when the pH was more than 4. Because there was a slime mold in less than pH4,when we experimented with oxalic acid 1.0mol/L, slime mold is likely to exhibit some chemotaxis to something other than pH. We want to examine the chemotaxis of slime molds against substances with a carboxyl group. And, slime molds dont move by only pH, so we want to test how substances affect slime molds For example: The relationship of organic acids and cell membrane receptors. Outlook Thank you for listening!!