Amphibians around the world are experiencing drastic population declines. Over 1/3 of amphibian species are in decline (Stuart et al. 2004). There are many causes for amphibian decline, amphibian skin infection by Batrachochytrium dendrobatidis, more commonly referred to as the Chytrid fungus, is a major cause of amphibian decline (Harris et al. 2009). The skin of amphibians is an important organ responsible for respiration, electrolyte balance, hydration and many other important physiological functions (Rosenblum et al. 2012). Amphibian skin also possess unique microbial communities. The microbial communities present on amphibian skin is part of the organisms innate immune system (Woodhams et al. 2007). There are multiple bacterial species present on the skin of amphibians that produce a protein called violacein (Becker et al. 2009 ). Violacein has antifungal properties and has been shown to inhibit the skin disease caused by the chytrid fungus on both natural and inoculated hosts (Becker & Harris 2010; Harris et al. 2009). The chytrid fungus has been found on every continent, except Antarctica, and though it has not been found in New York State, it has been found in many neighboring states and sampling efforts in New York have been limited (Bd-maps). Violacein producing bacteria as well as the violacein protein have been found on the skin of eastern red backed salamanders (Plethodon cinereus) in other regions of their range (Becker et al. 2009; Harris et al. 2009) where the species’ skin microbial interactions have been heavily researched.
Figure 1-PCR results using universal fungal primers with salamander samples
Figure 2-PCR results using chytrid specific primers with salamander samples and positive chytrid control sample
Figure 3-Results from PCR with universal fungal primers and chytrid primers
Figure 4-PCR results for detection of the violacein gene on salamander samples
Amphibian populations around the world are in decline. One of the major causes of decline in amphibian populations is the chytrid fungus, Batrachochytrium dendrobatidis. The eastern red backed salamander (Plethodon cinereus) is an important amphibian in U.S. eastern forest. Bacterial species that produce a protein called violacein have been found on eastern red backed salamanders in other areas of its geographic range . Violacein has antifungal properties and prevents the deadly skin infection caused by the chytrid fungus. DNA extracted from red backed salamanders was amplified using PCR. PCR results show that chytrid was not present on salamanders sampled. The violacein gene was successfully amplified from salamanders. The presence of violacein may be important in protecting the salamanders from chytrid if the fungus enters New York State.
I would like to thank Evon Hekkala and her laboratory at Fordham University for the use of their eastern red backed salamander samples. I would also like to thank Joyce Longcore at the University of Maine Chytrid Laboratory for her help and for providing chytrid fungus cultures for positive controls used in the study.
Thank you so much to Dr. Rubin, Kate Reid, and Catharina Grubaugh for all your help and guidance, I couldn’t have done it without you.
|This document was last modified 05/16/2014.|
This site is powered by the versatile Zope platform.
|This is a project of the Biology Department of Fordham University