Download or read book An Evaluation of Fluorescent Randomly Amplified Polymorphic DNA (FRAPD) as a Tool for Identifying Species Hybrids, and the Application of These Markers to Questions of Hybridization in Two Groups of Ohio River Basin Fishes written by Michael G. Sovic and published by . This book was released on 2011 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Randomly amplified polymorphic DNA (RAPD) has a number of characteristics that make it an attractive option for studies in hybrid zones. However, concerns regarding the repeatability of RAPD data have caused many researchers to opt for other types of genetic markers. In this dissertation, a series of modifications were applied to traditional (RAPD) methodology, and the modified RAPD markers were evaluated for their utility as a tool to identify species hybrids. Levels of repeatability were evaluated for these markers, and the estimated error rates fell within the levels of those generally accepted for studies employing dominant genotyping methods. The repeatability estimates were then incorporated into simulations to directly assess the power of dominant genetic markers in identifying various classes of parental and hybrid individuals. The level of performance varied with the number of loci analyzed, the error rates associated with the loci, and the levels of diversity between the parental taxa. However, many scenarios were identified that are likely to be encountered in natural populations in which the simulated markers performed very well, suggesting that the modified RAPD markers may serve as a viable option in many hybridization studies. Finally, two case studies are presented in which the modified RAPD markers are applied to address questions of hybridization in freshwater fishes of the Ohio River basin. In the first case study, hybrid saugeye (Sander vitreus x Sander canadensis), which are artificially produced and stocked into waters throughout Ohio, were evaluated to determine whether reproduction occurs by these fish. No evidence of reproduction was observed in the inland reservoirs of Ohio, suggesting that reproduction among F1 hybrid saugeye occurs very rarely, or not at all. However, evidence of reproduction by saugeye is presented from Sander spp. individuals collected from the Ohio River, where native populations of both parental species occur. In the second case study, fishes of the genus Carpiodes are examined in order to determine whether hybridization occurs in this group. Evidence of hybridization is presented for these fishes, and a combination of molecular data and morphological data suggest that the rates of hybridization may vary among different sympatric communities of Carpiodes spp. in the Ohio River basin. The direction of interspecific gene flow resulting from the hybridization also appears to be biased, with C. cyprinus sending genes into C. carpio more often than the reverse. The results of each of these two case studies are discussed in the context of their potential influences on the evolutionary trajectory of these groups. Finally, as part of the analysis of hybridization in Carpiodes, C. cyprinus was identified as a nonmonophyletic taxon according to mitochondrial cytochrome b sequence data. The patterns of genetic diversity observed at this gene suggest the potential that cryptic diversity occurs within C. cyprinus. Specifically, specimens collected from the Susquehanna River basin may be distinct from those in the Great Lakes and Ohio River basins. These data suggest that a reevaluation of the taxonomy of this group is warranted.