tailieunhanh - The analysis of partial dominance of intragenic mutations at the ADH locus in drosophila melanogaster at two different alcohol concentrations

The dominance of a de novo mutation determines its effect on the viability of the first and succeeding generations; therefore, it is a major factor in estimating the risk from mutations to human health. It is well established that large deletions lead to significant dominance. | Turk J Biol 27 (2003) 223-232 © TÜB‹TAK The Analysis of Partial Dominance of Intragenic Mutations at the Adh Locus in Drosophila melanogaster at Two Different Alcohol Concentrations Vatan TAfiKIN Department of Biology, Faculty of Art and Sciences, Mu¤la University, Mu¤la - TURKEY E-mail: vatantaskin@ Received: Abstract: The dominance of a de novo mutation determines its effect on the viability of the first and succeeding generations; therefore, it is a major factor in estimating the risk from mutations to human health. It is well established that large deletions lead to significant dominance, but until the recent development of molecular methods for amplification and sequencing of mutations it was not possible to determine the dominance of specific intragenic changes in DNA. The purpose of this study was to determine the dominance for a series of Adh-null mutations, each with a minimum mutation of a transition at one base pair that produced a single amino acid substitution. This study reports partial dominance of 14 2-CIEMS induced intragenic alcohol dehydrogenase (ADH) null mutations in Drosophila melanogaster previously sequenced. Two different alcohol concentrations, 8% and 10%, were used to determine alcohol tolerance. The percentage survival for 72 h was analyzed with 5 replicates for each mutation treatment level. Results showed a broad spectrum of dominance, from high dominance to apparently no dominance. Different sites of mutation had different effects on dominance. Two mutations, nBR140 and nBR149, were not statistically different from wild-type in all 3 statistical tests: (i) untransformed percentage survival, (ii) arcsine transformation and (iii) Johnson & Kotz transformation. Three mutations, nBR139, nBR150 and nBR164, were significantly different from the control at both alcohol concentrations in all statistical analyses. Key Words: Alcohol dehydrogenase (ADH), Adh-null mutations, Drosophila melanogaster, partial .