Genetic Control of TemperaturePreference in the Nematode

Caenorhabditis elegans

Akiko Mohri, Elji Kodama, Koutarou Kimura, Mizuho Koike, Takafumi Mizuno and Ikue Mori

Background

• Worms will migrate to cultivation temperature when on a temperature gradient (H&R, 1975)

• Worm will avoid temperatures paired with starvation

• If E. coli paired with new temperature, take 2-4 hours before worms will migrate to the new temperature

Neural circuit

Mori 1995

25˚C

15˚C

Thermotaxis Phenotypes

Isothermic

ThemophilicCryophilic

Athermotactic

N2aho-2hen-1

No ablation

ttx-3nsc-1

AFD/AIY ablation

lin-11

AIZ ablation

tax-2tax-4sel-12

RIA ablation

25˚C

15˚C

25˚C

15˚C

25˚C

15˚C

Figure 1

Table 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 10

Figure 11

Figure 12

Conclusions

• Respond differently to changes in temperature vs. feeding state

• aho-2 defective thermotactic avoidance