ARCHGEN: the first Brazilian laboratory exclusively for ancient DNA

Ancient DNA (aDNA) is that DNA extracted from old samples such as subfossils, mumies and museum specimens collected centuries ago. Besides that, all that DNA coming from samples which were not fixed properly for molecular studies, as collection specimens collected a few decades ago, must be considered aDNA.

Ancient DNA technique was first used in 1984 to recover DNA from a 150-year-old museum specimen of the extinct subspecies of the Plains Zebra Equus quagga (Higuchi et al., 1984). That first record of aDNA as a tool to solve identification problems proved to be good enough to determine the phylogenetic relationships of the species, allowing the development of a project for breeding and re-introduction of the Quaggas. Since then, this technique has been employed for different purposes and studies as for exemple, genetics and phylogenetics involving extinct species, conservation and recuperation of impacted communities, reposition of fishery resources among others.

However, due to the high grade of fragmentation and degeneration, the aDNA is highly susceptible to contaminations, and its study requires a series of measures aiming the isolation and sterilization of the space where the samples will be processed. To meet these measures was created the ARCHGEN: a laboratory dedicated exclusively to process and analyze ancient and difficult DNA. The ARCHGEN conforms to the basic requirements for the safe handling of samples and, consequently, to the reliability of the results. To this end, Dr. Priscilla C. Silva, then PhD student of PPG-Animal Biology, spent 10 months in the LAB, the Molecular Biology Laboratory of the Smithsonian Institution in Washington DC, USA. During this period, she developed and tested protocols for DNA extraction from ancient materials deposited in museums.

In continuing this project in ARCHGEN, Drs. Priscilla Caroline Silva and Maria Claudia Malabarba search to discover the true identity of type specimens of the fish family Characidae (tetras) deposited in different museums in Europe and North America for over 100 years! In 1917, they published an article (Silva et al. 2017) revealing the identity of a species of tetra collected by the Thayer expedition in 1864, and named in honor of Dom Pedro: the Deuterodon pedri. Currently, is being finalized a paper about the real location and identity of Tetragonopterus taeniatus: a lambari collected by Charles Darwin during the Beagle’s voyage in 1832. However, these researchers emphasize that museum specimens belonging to other biological groups preserved in via wet or dry, as insects, skins, hair, teeth, plants, etc. are capable of generating viable DNA.