Tuesday, 27 March 2012

A Development on the Tasmanian devil Tumour Disease


A Development on the Tasmanian devil Tumour Disease
By: Krisha Rajput - 42892513


Figure 1: Tasmania Devils
(Australian Reptile Park, 2010)
A recent article explores the Tasmanian devil (Sarcophilus harrisii, who is a marsupial) and its facial cancers. New research have identified that the facial cancer has been spread throughout the population by only one female devil. This was approximately sixteen years ago. The article, “’Immortal’ Tasmanian devil brings vaccine hope” by Andy Coghlan, discusses how Tasmanian devils have over time started becoming extinct. However, the article indicates signs of a vaccine that can help save the Tasmanian devils. Generally the spread of facial cancer in Tasmanian devils is said to have evolved by simply biting, mating and other ways in which they have interactions and physical contact. (Coghlan, 2012) Tasmanian devils usually like to bite for no reason sometimes; it is basically the way marsupials act. Data from the Australian State of Tasmania listed the Tasmanian devils in the endangered list in May 2008. (McCallum, 2008)

Devil Facial Tumour Disease (DFTD) was first established in 1996. After they were identified the population began to drop by more than 60% due to the DFTD. DFTD is believed to be a sexually transmitted disease and is very rarely found in immature devils such as newborns. (McCallum, 2008) There has been a recent development in Tasmanian devils and their tumours, as a vaccine hopes to save and prevent facial cancers in the devils. This issue is extremely important, primarily because the devils may potentially become extinct in a few more years. However, if vaccines are tested for, it can assist in saving the population and reduce the extinction rate significantly. (Coghlan, 2012)

Figure 2: A Suffering Tasmanian devil with Facial Tumour
(Save the Tasmanian Devil Program, 2010)

As Figure 2 depicts, there are many devils that have facial tumours and cannot be treated for accordingly. However, genetically  Karyotypes (‘are the chromosome pairs of a cell that are arranged by size and shape’) (Reece et al, 2012) and the molecular genetics researches both indicate that all tumours are a single clone, which are then derived from an individual devil. The tumours found in the devils all differ genetically from the devil that spread the tumour originally. Therefore, the tumour cells and the tumours are completely different. The tumour cell is the infective agent, whereas, the tumour itself is the infectious cell line. Usually, DFTD is situated on the face, and could be located in the oral cavity; however, the cancer can be found in other locations also. (McCallum, 2008) (Reece et al, 2012) The main reason for generating a vaccine is mainly due to the DFTD cells. (Coghlan, 2012)
 
 
“Now we know which genes are mutated, we can begin assessing which ones might be good antigens for a vaccine,” says Elizabeth Murchison, from the Wellcome Trust Sanger Institute in Hinxton, UK. (Coghlan, 2012) There has not been an exact location identified by Murchison about where the mutation is, however, the genes that are in devils become mutated once it has been in contact with an infectious devil (frequently through biting). Generally, the facial tumour occurs because the immune system of the devils cannot identify the disease. (Coghlan, 2012)

Figure 3: A baby Tasmanian devil (Ki Mae Heussner, 2008)
Lastly, in conclusion, it is evident that to manage DFTD it will be essential to develop a vaccine that can help restore the Tasmanian devil population. Although the vaccine is yet to be made and tested, there has been development with it since the source of the mutation has been located. Once it has been tested for, there will be an increase in Tasmanian devils throughout Australia.









Bibliography:

1.       Andy Coghlan, 2012, ‘Immortal’ Tasmanian devil brings vaccine hope, viewed 14 March 2012, http://www.newscientist.com/article/dn21489-immortal-tasmanian-devil-brings-vaccine-hope.html?full=true&print=true

2.       Hamish McCallum, 2008, Tasmanian devil facial tumour disease: lessons for conservation biology, viewed 18 March 2012, http://dx.doi.org.ezproxy.library.uq.edu.au/10.1016/j.tree.2008.07.001

3.       Reece, Jane B; Meyers, Noel; Urry, Lisa A; Cain, Michael L; Wasserman, Steven A; Minorsky, Peter V; Jackson, Robert B; Cooke, Bernard N, 2012 ‘Unit 8 Ecology: An interview with Hamish McCallum’, Campbell Biology, Australian 9th Edition, Pearson, Australia pp. 1168 – 1169

4.       2010, Australian Reptile Park, Devil Ark, viewed 19 March 2012, http://www.reptilepark.com.au/devil-ark/

5.       2010, Save The Tasmanian Devil Program, viewed 19 March 2012, http://www.tassiedevil.com.au/tasdevil.nsf/folder/_thedisease

6.       Ki Mae Heussner, 2008, Tasmanian devil could be extinct in 20 years, viewed 19 March 2012, http://www.wekidyounot.org/wkyn/printthread.php?tid=1291

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