The Body Clock in Cells A Molecular Phylogeny of Circadian Systems
Date of Award
2006
Document Type
Thesis
Degree Name
Bachelors
Department
Natural Sciences
First Advisor
Beulig, Alfred
Keywords
Molecular Evolution, Molecular Phylogeny, Circadian Rhythms, Body Clock, Biological Rhythms, Molecular Clock, Biological Clock, Evolution of Sleep, Natural Selection, Oscillator, Cell Biology, Biological Psychology
Area of Concentration
Biology
Abstract
An endogenous clock provides a significant adaptive advantage to species across taxa. Intrinsically Photosensitive Retinal Ganglion Cells (ipRGCs) provide photic input to the master clock in vertebrate brains, allowing daylight entrainment of circadian systems. Cellular and genetic data suggests that ipRGCs have more in common with invertebrate, rhabdomeric photoreceptors than the vertebrate ciliary photoreceptors, but a number of experiments are necessary to complete the analysis and highlight the functional similarities between invertebrate model photoreceptors and ipRGCs. Melanopsin, the chromophore that grants photoreactivity to these retinal ganglion cells, likely emerged from a genetic lineage analogous to the rhabdomeric photoreceptors, not vertebrate ciliary types, according to functional and morphological homologies. In this study, phylogenic trees were derived from changes in the amino acid sequences of melanopsin. Constructed trees did not provide conclusive statistical support for this hypothesis.
Recommended Citation
Kalmbach, Keri, "The Body Clock in Cells A Molecular Phylogeny of Circadian Systems" (2006). Theses & ETDs. 3668.
https://digitalcommons.ncf.edu/theses_etds/3668
Rights
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The New College of Florida, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.