Title

DNA Barcoding in Saprolegnia

Presenter Information

Ryanne Mueller

Document Type

Oral Presentation

Location

SURC Ballroom A

Start Date

17-5-2012

End Date

17-5-2012

Abstract

Saprolegnia is a genus of common freshwater protists that have been found to contribute to the mortality of amphibians and fish in hatcheries. One problem with these protists is that they are very hard to identity down to the species level. Traditionally, different species have been identified based on the anatomy of their reproductive structures, but recent research has clearly indicated that this is more unreliable than to compare the genetic relationships among these protists. The goal of our research is to simplify the process of identification by finding an appropriate region of DNA that is suitable for DNA barcoding; identification through the use of standardized short sequences of DNA. Another problem in the selection of an appropriate barcoding region in these organisms is the observation that the two main (nuclear ITS and mitochondrial CO1) genes used in DNA barcoding studies produce conflicting phylogenies and species boundaries. In order to better understand the evolution of these protists and find the best choice for a DNA barcoding gene, multiple additional mitochondrial genes from a number of isolates of Saprolegnia species were amplified via PCR and sequenced. Phylogenetic trees for each gene were estimated using several different methodologies and resulting trees were compared to the trees from each gene. Preliminary results suggest that differences among gene phylogenies may be due to hybridization or lineage sorting.

Poster Number

12

Faculty Mentor(s)

James Johnson, Steve Wagner

Additional Mentoring Department

Biological Sciences

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May 17th, 8:30 AM May 17th, 11:00 AM

DNA Barcoding in Saprolegnia

SURC Ballroom A

Saprolegnia is a genus of common freshwater protists that have been found to contribute to the mortality of amphibians and fish in hatcheries. One problem with these protists is that they are very hard to identity down to the species level. Traditionally, different species have been identified based on the anatomy of their reproductive structures, but recent research has clearly indicated that this is more unreliable than to compare the genetic relationships among these protists. The goal of our research is to simplify the process of identification by finding an appropriate region of DNA that is suitable for DNA barcoding; identification through the use of standardized short sequences of DNA. Another problem in the selection of an appropriate barcoding region in these organisms is the observation that the two main (nuclear ITS and mitochondrial CO1) genes used in DNA barcoding studies produce conflicting phylogenies and species boundaries. In order to better understand the evolution of these protists and find the best choice for a DNA barcoding gene, multiple additional mitochondrial genes from a number of isolates of Saprolegnia species were amplified via PCR and sequenced. Phylogenetic trees for each gene were estimated using several different methodologies and resulting trees were compared to the trees from each gene. Preliminary results suggest that differences among gene phylogenies may be due to hybridization or lineage sorting.