Heat-Stress Resistance & Aging

By: Scott Scholz

Phillips Lab ’09

Mentor: Rose Reynolds

Aging:

• The gradual changes in the structure and function of humans and animals that occur with the passage of time, that do not result from disease or other gross accidents, and that eventually lead to the increased probability of death as the person or animal grows older.

Aging

Vs.

70 year old men

What Determines the Differences Between Individuals?

• Are there genetic differences in humans that cause us to age at different rates?

• Model: Caenorhabditis remanei

• In chemosensory genes C. remanei has been found to have 200x the genetic diversity of C. elegans.

Jovelin (2008)

Variation of Lifespan in C. Remanei

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Reynolds (Unpublished)

Insulin-like Signaling Pathway

Cohen & Dillin 2008 Stress resistance and Lifespan are genetically correlated!

Heat-Stress Resistance• Heat-stress resistance

can be very important for a soil-dwelling worm.

• Much more time efficient way of testing lifespan.

• Find other players in regulation of lifespan and stress-response.

My Goals

• Develop an assay to test heat-stress resistance.

• Assay several natural C. remanei isolates for variation in heat-stress resistance.

Develop Heat-Stress Assay

• Use the representative C. remanei line PX323 to find the LD50 of heat.

• Many challenges in treating worms with an even “dose” of heat.– Heat uniformity over area

– Heat stability over time

– Even heating to target temp

Approach

Virgin Adult Females

Pick L4 Females

24+ hrs

16 hrs

31 Alive / 60 Total = 0.52 Survival.

52% Survived

Test Heat-Stress Resistance

• Find LD50 temperature (over 16hrs)

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Future •Test several natural C. remanei isolates for variation in heat-stress resistance.

•Use known markers to identify regions across the genome that affect heat-stress resistance, lifespan or both!

•Compare male vs. female heat-stress resistance and the significance of C. remanei being dioecious.

•Reproduction?

Thanks!

•Rose Reynolds

•The UO SPUR program

•Peter O’Day & Chelsie Fish

•The Entire Phillips Lab