Download American Bullfrog (Lithobates catesbeianus) Phylogeny

American Bullfrog
(Lithobates catesbeianus)
Phylogeny
Lisa M. Wilson
April 26, 2010
Introduced Species
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Introduced species are a major cause of
endangerment of species in the U.S.
400 of 958 species in U.S.
 Huge economic impact
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American Bullfrog
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Successful colonizer
Native to North America east of the Mississippi
River
Introduced to western North America, China,
Venezuela, Brazil, Europe…
Preys on and outcompetes native species
Acts as reservoir and vector of chytrid
Invasive Management
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Eradication impossible
Management for coexistence
Prevention!
Climate matching is best predictor
 Legislation to control intentional introductions
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Is there variability between populations within
Bullfrog range that affect climate matching
ability?
Project Goal
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Use available sequence data to look for
differences between populations that may be
related to climatic variables
Methods
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Cytochrome b sequences for Bullfrog and Green
Frog from NCBI
Aligned in Seaview using ClustalW
Maximum-likelihood tree created with RAxML
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1000 bootstraps
Tree visualized and modified in FigTree
Compared arrangement of source populations in
tree with climate variables
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Locations from original papers (Austin et al. 2003, 2004)
Results
Drought Tolerance
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Closely related and relatively recent
Founder effects
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Requires same genetic drift between all populations
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China, Java, California, Texas, Missouri, Kansas?
From most arid locations
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Cyt b could be related to drought tolerance
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Role in cellular respiration
Discussion
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No influence of temperature
Thermal tolerances not heritable
 Cyt b not related to thermal tolerances
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Distribution of cyt b haplotypes determined by
refugia during last glacial maximum
New York is basal, Ontario closely related to Florida
 High rate of gene flow – human mediated transport?
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Summary
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Limited by data availability
Cytochrome b only widely available sequence
 Limited known locations
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More populations, more genes, ideally related
genes!