Using Microsatellites to Examine the Effects of Urban Development on Pond-Dwelling Turtles

Kristine Grayson, Peter Leese, David Wessner, and Michael E. Dorcas

 

Development and habitat fragmentation is fast becoming one of the greatest threats faced by wildlife.  As suitable habitats for species are reduced to smaller and smaller patches that are farther and farther apart, species become exposed to a host of problems associated with population fragmentation.  Because of this phenomenon populations are increasingly forced to rely on migration of individuals both to allow for mixing of genetic material and to found new populations, replacing ones that go extinct.  Freshwater, pond-dwelling turtles provide excellent models for studying the effects of habitat fragmentation on metapopulation dynamics as they have been shown to travel across land to other ponds. 

Objective:
To increase our understanding of the impact of development and habitat fragmentation by examining gene flow of painted turtle populations in the Greater Charlotte North Carolina area. The amount of gene flow between populations will be estimated using DNA microsatellite analysis.


Part #1- Turtle Trapping

Chrysemys picta
Traps used to catch turtles
Map showing three ponds trapped thus far

 

Part #2- DNA Analysis

 

 

 

 

 

 

Turtles were trapped and tissue samples were taken in lab. DNA was extracted from tail tips using a Promega Wizard Genomic DNA Purification kit and then amplified using PCR and a DNA microsatellite primer. Amplified DNA was then run on a 2% agarose gel to check for proper extraction and amplification.
These sections on the gels give us the DNA microsatellites present in different individuals; next, these results will be analyzed using an automated sequencer to compare the size of the DNA microsatellites among individuals.
DNA fingerprint of 10 individuals after amplification and electrophoresis.

 

This research was funded by The Davidson College Department of Biology, an Associated Colleges of the South Environmental Program Student Development and Engagement Alliance Grant and a Stone Fund Grant to KLG

View Project Proposal Here

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