Early Life Stress and Telomere Length in Cichlids

• Author / Creator

  Fjellner, Kennedy Lyn

• Early life exposure to stress can have life-long effects on an organism. These effects may be detrimental, or they may be adaptive if they allow the organism to develop an adult phenotype which better matches the environment predicted by the stressor. Early life stress influences many traits, including growth rate and stress coping style. Early life is suggested as a time where oxidative stress increases due to the increased metabolic growth demand. Higher growth rates impose increased oxidative stress, which has been linked to telomere shortening. Here I examine the link between age, growth, stress, coping style, and telomere length. In the first study I quantified telomere length in cichlid species Astatotilapia burtoni across four different age groups. In the second study I quantified behaviour, and cortisol hormone levels and telomere per single gene copy in two types of convict cichlid (Amatitlania nigrofasciata) tissue for stress treated and control fish. I found that liver telomere length was not related to age in A. burtoni but fin telomere length did increase with age in fin tissue. In A. nigrofasciata we found that there was no relationship between stress treatment, growth rate or residual body condition. There was no significant difference between the stress treatment and control groups relative telomere length in fin or liver tissue. Principal components of the behavioural measures showed that there was an interaction of stress treatment, fin telomere length and PCA components. Fish in the stress treatment group with longer fin telomeres tended to be less exploratory and have a more reactive coping style than controls. These results suggest that telomeres in cichlids do not follow the same pattern of attrition as found in other species such as birds and humans. The different pattern of telomere dynamics found in cichlids could be suggestive of high levels of telomerase expression in somatic tissue due to their ability to grow indeterminately.

• Subjects / Keywords

  • Early Life Stress
  • Telomere
  • Stress
  • Fish
  • Cichlid

• Graduation date

  Fall 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-tn97-yg83

• License

  Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.