Photo: two thylacinus in the Washington D.C. National Zoo, c. 1906. (Credit: Photograph by E.J. Keller, from the Smithsonian Institution archives (via Wikipedia))
All the genes that the exotic Tasmanian Tiger inherited only from its mother will be revealed by an international team of scientists in a research paper to be published on 13 January 2009 in the online edition of Genome Research. The research marks the first successful sequencing of genes from this carnivorous marsupial, which looked like a large tiger-striped dog and became extinct in 1936.
The research also opens the door to the widespread, nondestructive use of museum specimens to learn why mammals become extinct and how extinctions might be prevented.
“Our goal is to learn how to prevent endangered species from going extinct,” said Webb Miller, a Penn State professor of biology and of computer science and engineering and a member of the research team that includes scientists from the United States, Sweden, Spain, Denmark, the United Kingdom, and Germany. “I want to learn as much as I can about why large mammals become extinct because all my friends are large mammals,” Miller said. “However, I am expecting that publication of this paper also will reinvigorate discussions about possibly bringing the extinct Tasmanian Tiger back to life.”
The team’s research relies on new gene-sequencing technology and computational methods developed by Miller and Stephan C. Schuster, a professor of biochemistry and molecular biology at Penn State. The new methods involve extracting DNA from the hair of extinct specimens, not from bone, which has been used in previous studies of extinct species. The team’s work reveals that hair is a powerful time capsule for preserving DNA over long periods and under a wide range of conditions. “I think of hair as a shrine for ancient DNA,” Schuster said. “It is sealed so well that not even air or water are able to penetrate the DNA stored inside. Most importantly, bacteria cannot reach the DNA as long as the structure of the hair remains sound.”
“Tasmanian Tiger” is a common name of the extinct thylacine species (Thylacinus cynocephalus), which is more closely related to kangaroos and koalas than to dogs or tigers. The last known specimen died in a Tasmanian zoo in 1936.