A study of euteleost phylogeny based on the genomic diversity of ribosomal DNA as a function of euteleost evolution.
Item
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Title
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A study of euteleost phylogeny based on the genomic diversity of ribosomal DNA as a function of euteleost evolution.
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Identifier
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AAI9521281
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identifier
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9521281
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Creator
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Jahangir, Z. M. G. Sarwar.
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Contributor
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Adviser: Ronald A. Eckhardt
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Date
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1995
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Molecular
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Abstract
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The present knowledge of euteleost phylogeny is based primarily on morphological characters. However, due to homoplasy, convergence and atavism of morphological characters, euteleost phylogeny still remains unresolved. The monophyly of Cyprinidae, Esocoidae, Protacanthopterygii, Acanthopterygii and their interrelationships are in question.;Recently some researchers have started to apply molecular techniques to analyze the phylogeny of fishes at various taxonomic levels. Some of these investigations involved DNA sequencing and restriction endonuclease recognition site characterization of mitochondrial DNA as well as nuclear ribosomal DNA (rDNA) in addition to other methods. Many of these studies included representatives from fish taxa to address the phylogeny of other organisms but did not address fish phylogeny directly.;Since rDNA is universal to all organisms, tandemly repeated in eukaryotes, contains both highly conserved and rapidly evolving domains and is known to evolve in a concerted fashion, this molecule is an attractive model to study the phylogenetic relationships of both closely and distantly related organisms. This study was directed to characterize and identify the molecular differences among the rDNAs of representative euteleosts in terms of restriction endonuclease (RE) recognition sites, and then compare these sites in order to analyze the euteleost phylogeny. In order to do that, RE maps of representative euteleost rDNAs were constructed, homologous RE sites were aligned and an rDNA RE recognition site character matrix was generated. In addition, a morphological character matrix was generated based on the available literature. Based on the euteleost rDNA RE and morphological characters alone, and in combination, separate phylogenetic trees were reconstructed using Hennig86 parsimony analysis and compared.;Ribosomal DNA RE alone, and in combination with the morphological characters, supported the monophyly of the Euteleostei, the Neognathi and the Acanthopterygii. The rDNA characters alone supported paraphyly of the Protacanthopterygii and in combination with morphological characters, supported polyphyly. This study suggests the need for additional euteleost representatives and RE to characterize their rDNA further in order to resolve the euteleost phylogeny.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
