PARENT SESSION
IP03 - Biomonitoring
Chair: Allen, Joel1, 1 PO Box 310559, Denton, TX
Co-chair: Lazorchak, Jim2, 2 US EPA, Cincinnati, OH
2:10 PM to 5:30 PM - Sunday, 17 November 2002
Room Room 150 G
(IP22) Using Microsatellites to Analyze Genetic Variability in Southern Redbelly Dace (Phoxinus erythrogaster) of Knox County, Ohio.
Kendall, Neala*,1, Heithaus, E.2, 1 Exponent, Oakland, CA, USA2 Kenyon College, Gambier, OH, USA
ABSTRACT- Higher levels of genetic variability in natural populations have been associated with higher fitness levels and evolutionary and demographic stability (Wright, 1978 and Soule, 1976). One promising mechanism for assessing genetic variability is the use of microsatellite markers, which are short, usually noncoding, codominant, tandemly repeating nucleotides that each occur in only one place in the genome. Microsatellite markers were applied to southern redbelly dace (Phoxinus erythrogaster) to study the level of variation within and among different localities of Knox County, Ohio. Previous studies have shown that redbelly dace possess no allozyme variability (Myers, 1996), but this study demonstrated genetic variability at microsatellite loci. Fin clip samples from 190 redbelly dace were collected from nine sites in two Knox County, Ohio watersheds for DNA extraction and analysis. Twenty different pairs of primers developed for five related fish species were used to amplify microsatellite loci from the dace with polymerase chain reaction (PCR), which were visualized by polyacrylamide gel elecrophoresis (PAGE). Nine of these primers consistently identified a microsatellite and only one microsatellite, Ca3, had more than five alleles distributed over more than 1/6th of the sampled fish. The 12 alleles of this microsatellite were not distributed randomly among fish from different sites (P = 0.001). Deviation from Hardy-Weinberg frequencies was seen in fish from two sites (P < 0.01). Fish from one site, the furthest north, were most differentiated from the fish from the other eight sites. Geographic proximity was not correlated with genetic similarity for the most part. This study supports the use of microsatellites in assessing Knox County redbelly dace genetic variability. The fish are most likely not at immediate threat to subdivision or extinction due the presence of some genetic variability. However, it will be important to monitor fish from the most northern site and understand their genetic patterns compared with other Knox County redbelly dace.
Key words: Microsatellites, Southern Redbelly Dace (Phoxinus erythrogaster) , Genetic Variability