telomeres and senescence in sockeye salmon
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RAPID SENESCENCE IN SOCKEYE SALMON
INSIGHTS FROM TELOMERES
Caroline StorerTom Quinn Steven Roberts
Alaska Salmon Program Symposium 2010
Senescence in sockeye salmon
• Adaptive variation of senescence within populations
• Significant variation in in-stream longevity (i.e., rate of senescence) among populations
• Links to other aspects of fitness such as energetic investment in gonads versus body stores (Hendry et al.
2004)
WHAT PHYSIOLOGICAL PROCESSES REGULATE
SENESCENCE IN SOCKEYE SALMON?
Study site
Previous research (2008-2009)
• Baseline information on physiological changes between “arriving” and senescent salmon
• Cortisol signaling declines during senescence
• Molecular chaperone protein (HSP) is up-regulated during senescence
• Molecules controlling “other” primary process are differentially expressed (immune, reproduction, olfaction, and memory)
New approach
Examine new physiological process:
New approach
Examine new physiological process:Telomere shortening
Why telomeres?
Why telomeres?
• Telomeres shorten in length with age
• Telomere shortening is significantly correlated with decline in physiological health (Terry et al. 2008)
• Telomere length can be inherited (Atzmon et al. 2010)
• Critical telomere length could be one possible trigger of senescence (Armanios 2009)
New question
Does telomere shortening directly trigger senescence and/or regulate rate of senescence in
sockeye salmon?
Samples (2010)
• Fin clips and tagging of arriving fish
• Early and late arriving fish
• Fin clips of tagged fish at multiple “in-stream” time points (i.e. day 2, day 6)
• http://goo.gl/tCeJ7
New methods
• High-throughput PCR based fluorescent assay for the normalized measurements of relative telomere length
New methods
• High-throughput PCR based fluorescent assay for the normalized measurements of relative telomere length
Log Telomere Length
Fluore
scence
Preliminary results
Juvenile Adult0
10
20
30
40
50
60M
ean
Rela
tive T
elo
mere
Len
gth
Summary and next steps
• We can measure telomere length
• However, assay needs to be optimized for greater sensitivity
Summary and next steps
• We can measure telomere length
• However, assay needs to be optimized for greater sensitivity
• Is there a difference in telomere length between early (slow senescing) and late (fast senescing) arriving fish?
• Does telomere length shorten during rapid senescence?
Implications
• Provides insight into the evolution of life history strategies and phenotypic variation in longevity
• Rapid senescence in sockeye salmon could be used a model to study aging and longevity in other organisms
Acknowledgments
• The 2010 sampling crew, especially Curry Cunningham, Jackie Carter, Brian Quinn, and Wes Larson
• Leslie Jensen
• The Alaska Salmon Program
• Roberts Lab
• Seeb Lab
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