Characterization and evolution of peridinin-chlorophyll a binding protein gene families in symbiotic dinoflagellates
| dc.contributor.advisor | Hillis, David M. | en |
| dc.contributor.advisor | Vize, Peter D. | en |
| dc.creator | Reichman, Jay Randall | en |
| dc.date.accessioned | 2008-08-28T21:37:36Z | en |
| dc.date.available | 2008-08-28T21:37:36Z | en |
| dc.date.issued | 2002 | en |
| dc.description.abstract | This dissertation consists of three integrated chapters. Chapter One presents the first genomic characterization of the PCP gene family from a symbiotic dinoflagellate, Symbiodinium sp. from Hippopus hippopus (Symbiodinium 203). Symbiodinium 203 has long PCP genes organized like those of Amphidinium carterae and Lingulodinium polyedra, but with a putative promoter that is different from L. polyedra. There are at least 14 distinct coding regions out of 36 ± 12 PCP genes in this family. Diversity of Symbiodinium 203's PCP gene family appears to be consequence of low levels of concerted evolution and acts as a primary source of variability in PCP isoforms. Predicted amino acid substitutions in Symbiodinium 203's PCP apoproteins result in shifts of isoelectric points, and protein modeling suggests that polymorphic sites may influence light harvesting of holoproteins. In Chapter Two, the first PCP coding sequences from S. pilosum, Symbiodinium sp. from Dichocoenia stokesii, S. pulchrorum and S. kawagutii were presented. Diverse PCP gene families occur in all major clades of Symbiodinium and in both size classes of the gene. As with Symbiodinium 203 in Chapter One, these PCP gene families do not appear to have been homogenized through mechanisms leading to concerted evolution. The predicted PCP apoproteins from S. pilosum and S. kawagutii have calculated isoelectric focusing points that generally match values previously measured for these species, which supports the hypothesis that genetic polymorphism is the primary source generating differences in PCP isoforms. Protein modeling produced a putative tertiary structure for S. pilosum apoproteins and was used to identify polymorphic sites in S. pilosum and S. kawagutii PCPs that could affect spectral tuning of peridinins. And Chapter Three contains the first phylogenetic analyses of the evolution of dinoflagellate PCP gene families. The objective of this section is to estimate the selective pressure at the codon level within PCP genes. PCP polymorphism is ancient, however, the polymorphism is not maintained by positive selection. Codon sites within PCP genes are evolving under purifying selection and are subjected to net reduced levels of concerted evolution. Isoform diversity is probably selected for within a functional range. | |
| dc.description.department | Biological Sciences, School of | en |
| dc.format.medium | electronic | en |
| dc.identifier | b57198354 | en |
| dc.identifier.oclc | 56908019 | en |
| dc.identifier.proqst | 3110677 | en |
| dc.identifier.uri | http://hdl.handle.net/2152/868 | en |
| dc.language.iso | eng | en |
| dc.rights | Copyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works. | en |
| dc.subject.lcsh | Protein binding | en |
| dc.subject.lcsh | Dinoflagellates | en |
| dc.subject.lcsh | Chlorophyll | en |
| dc.title | Characterization and evolution of peridinin-chlorophyll a binding protein gene families in symbiotic dinoflagellates | en |
| dc.type.genre | Thesis | en |
| thesis.degree.department | Biological Sciences, School of | en |
| thesis.degree.discipline | Ecology, Evolution, and Behavior | en |
| thesis.degree.grantor | The University of Texas at Austin | en |
| thesis.degree.level | Doctoral | en |
| thesis.degree.name | Doctor of Philosophy | en |