Later that year, a female and her three cubs arrived at the zoo. However, by the mid-1930s, the thylacine was extinct, leaving behind only preserved museum specimens.
In a study published online today in Genome Research (www.genome.org), researchers have used state-of-the-art DNA sequencing technology to analyze preserved thylacines, including one of those brought to the National Zoo more than 100 years ago, making novel discoveries in thylacine genomics and the burgeoning field of "museomics."
The thylacine was actually not a tiger at all, rather a marsupial with many dog-like features—a striking example of convergent evolution in mammals. Extensively hunted by farmers, the thylacine was becoming increasingly rare in the wild at the time the National Zoo acquired the female and cubs, and was declared extinct in 1936 upon the death of the last captive animal. Genetic sequences sampled from the preserved specimens of the National Zoo thyalcine family have been studied in recent years, however these investigations were severely limited by DNA contamination and degradation.
Now, in a strategy nicknamed "museomics," researchers are using improved methods for sampling DNA combined with the latest sequencing technology to analyze preserved museum samples. In this study, an international team of scientists has sequenced mitochondrial and nuclear DNA from the hair of the male thylacine offspring brought to the National Zoo in 1902 and a female that died in the London Zoo in 1893. In addition to refining the place of this unusual animal in evolutionary history, genetic clues to the impending extinction of the thylacine became apparent.
"What I find amazing is that the two specimens are so similar," said Dr. Anders Götherström of Uppsala University in Sweden. "There is very little genetic variation between them." Götherström, a co-author of the study, explained that a lack of genetic diversity is indicative of a species on the brink of extinction, and we are now observing this more than 70 years later.
In addition to using the mitochondrial genome sequence to study the phylogeny of the thylacine, the authors also investigated the collection of genetic material of microbial and viral origin (the "metagenome") present on the museum samples. Interestingly, the research team found distinct differences in the microbial content of the hair of the wild-born thylacine from the London Zoo and the captive-born thylacine from the National Zoo. Furthermore, the authors noted that the specimens were preserved by differing methods. "Analyzing the microbial content of museum specimens will therefore allow us to gain insight into the microbial flora that lives on the exhibit samples and help to develop means to further protect them," said Dr. Stephan Schuster of Penn State University, also an author of the report.
This work has established the groundwork for more detailed genetic analysis of the thylacine, opened the door to more museomic studies using the treasure trove of museum specimens worldwide, and will raise dialogue about even bigger projects. "The large amount of mitochondrial and nuclear DNA gained in our study demonstrates the feasibility of a thylacine genome project," explained Schuster. "It will also revive discussions on the possible resurrection of the animal."
Peggy Calicchia | EurekAlert!
Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy