The effects of circadian rhythm disruptions on monarch butterflies Open Access

Aljohani, Ahmed (Spring 2022)

Permanent URL: https://etd.library.emory.edu/concern/etds/j098zc362?locale=pt-BR%2A
Published

Abstract

Organisms have evolved internal biological clocks, known as circadian rhythms, to regulate their physiological functions. Disruptions of circadian rhythms have been associated with the rise of different health complications in multiple vertebrates and mammals, including humans, known as “shift work diseases“.Little is known regarding the developments of such diseases, but one explanation is that the misalignment of circadian clocks directly impacts immune function. Multiple studies have implemented animal models to study this phenomenon in animals. However, most models are heavily focused on a small number of nocturnal species, which may be poor reflections of diurnal situations, thereby highlighting the need for more circadian studies to include diurnal animals. Here we use the diurnal monarch butterflies (Danaus plexippus), one of the most acquainted migratory animals, to investigate the possibility of using them as a diurnal animal model for circadian disruptions and immune studies. Monarchs fight off infections from a naturally occurring virulent parasite; however, little is known about the relationship between their circadian rhythm and immunity. We exposed monarchs to multiple circadian disruptions to investigate their immune rhythmicity. Additionally, we observed monarchs’ behavior to determine if monarchs retrain their circadian rhythms after being disrupted. Our results showed a negative effect on the immune response when monarchs larvae were reared in constant darkness; however, we did not observe immune response rhythmicity in monarchs. Behavioral assays showed that monarchs have sleep rebound behavior to retrain their biological clock after a disruption period characterized by constant exposure to light.  Further investigations into immune mechanisms using other immune measures such as cell lines or using infected monarch butterflies could clarify how circadian rhythms regulate monarchs’ immune response against parasite infection.

Table of Contents

Introduction .....................................................................................................................................1

Method ............................................................................................................................................4

Animal Husbandry  ..........................................................................................................4

Immune stimulation and humoral zone of inhibition........................................................7

Statistics…………................................................................................................................ 7

Results ............................................................................................................................................. 7

Circadian disruptions effect on monarchs’ behavior……………......................................... 7

Circadian disruptions effect on monarchs’ immune response......................................... 11

Discussion........................................................................................................................................ 13

References ...................................................................................................................................... 17

About this Honors Thesis

Rights statement
  • Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.
School
Department
Degree
Submission
Language
  • English
Research Field
Keyword
Committee Chair / Thesis Advisor
Committee Members
Last modified

Primary PDF

Supplemental Files