Geotaxis of Slime Mold · 2014. 3. 17. · First...

Slime Mold

Koshi high school of Fukui Erina Morita Misako Kato

Yuina Tanikawa

First We  found  that  slime  mold  may  have  

nega5ve  geotaxis  from    the  results  of  our  

seniors’  experiment.  

We  want  to  research  slime  mold  because  

we  were  interested  in  it.  

What  is  Slime  mold?

True  slime  mold

Cellularity  slime  mold Cellular  slime  mold

Underside  of  roBen  trees・logs  

Fallen  leaves  

Slime  mold

粘菌とは…？ This  is  Slime  mold!!

Figure Exploratory  experiment

Outcome

90%

91%

92%

93%

94%

95%

96%

97%

98%

99%

100%

1day 2day 3day 4day 5day

Top

Bottom

Experiment  Ⅰ：about  Existence  of  geotaxis

Result 12.5%  of  slime  molds  showed  that    they  didn’t  have  nega5ve  gravitaxis.  

87.5%  of  slime  molds  showed  that  they  have  nega5ve  gravitaxis.

Considera5on

Slime  molds  mostly  moved  upward.  

It  is  thought  that    they  have  nega5ve  gravitaxis.

Experiment  Ⅱ:  About  migra5on  pathway

AQer  6  hours  rotated  90  °or  180°  

Result

Use  bigger  petri  dish

Considera5on

It  is  thought  that  they  have  a  property  to  avoid  going  over  the  same  path.

They  didn’t  go  over  their  path  from  before.  

The  Whole  Considera5on

They  leave  the  traces  such  as  chemical  substances  on  their  path.  

Avoid  the  path  where  they  cannot  expect  to  get  food.  

In doing so...

The  difference  in  how  the  slime  molds  move  may  depend  on  the  amount  of  food  and  the  strength  of  s5mulus  （gravity,  light,  and  chemical  substance）.

Future  Ques5ons What  is  the  material  leQ  behind  aQer  the  slime  mold  passes?  

Why  does  the  slime  mold  move  to  avoid  it?    

How  does  the  slime  mold  move  when  signals  (gravity,  light,  and  chemical  substance)  are  changed?  

Thank  you  for      

           listening!!