The genetic barcode of the jungle of Misiones

In the jungle of the province of Misiones Tabebuias, marfims (guatambú), laurels and peterbí (Cordia tricótoma) are some of the two hundred tree species which, together with rivers and streams, house the richest terrestrial and aquatic fauna of the country. Thus, it is the natural area with the greatest biodiversity in Argentina.

Since 2010, researchers, museums, institutes, universities and laboratories of 25 countries in the world – Argentina among them – participate in the International Barcode of Life (IBOL) Project whose main objective is to obtain the “genetic footprints” of the species. The idea is to register the DNA barcodes of all flora and fauna of the planet to build a database available for scientists of the entire world. This tool allows researchers to identify species faster and use that information for forensic, health and preservation tasks, among others. Besides, this technique helps to discover a huge cryptic diversity. The CONICET has been part of this project for five years.

The Bernardino Rivadavia Natural Sciences Museum (MACN, CONICET) and the Fundación Bosques Nativos Argentinos para la Biodiversidad [Argentine Native Forests Foundation for Biodiversity] work to obtain genetic barcodes of the fauna of the forest of Misiones. The Foundation provided the collection of specimens, its labelling and transportation towards the Museum where they are prepared and photographed. Then the DNA is extracted and amplified, and in the case of the vertebrates, the reseachers work with a segment of the mitochondrial gene known as IOC. The tissues are preserved in the National Collection of Deep-Frozen Tissues and the amplified material is sequenced.

“From all the environments Argentina has, the most diverse are the jungles located in the northeast and northwest of Argentina: the jungle of Misiones and the yungas, respectively. In order to create this library with barcode sequences to identify species, we focused on the area with the highest number of species”, Pablo Tubaro, principal researcher at the CONICET and director of the MACN, explains.

Nahuel Schenone, biologist, member of the Argentine Native Forests Foundation for Biodiversity and director of the Centro de Investigaciones Antonia Ramos (CIAR) [Antonia Ramos Research Centre] highlights the importance of studying the forest of Misiones: “This area was not analysed, there was not enough information regarding the biodiversity of the centre of the province because the national parks were more attractive to be studied. The information obtained in this project showed that in many cases the diversity is greater than in national parks that used to be analyzed, such as the Iguazú”, he comments.

Regarding that, Esteban Avigliano, CONICET posdoctoral fellow at the University of Buenos Aires (UBA) and member of the Foundation adds that it is an area that has a lot to show. With this project, the scientists discovered several new species of insects, fungi and fish. “As we found them, we realized that we have to concentrate on this place to preserve not only the biodiversity but also the resources such as the forest cover, the pure water of the rivers and streams which can be used in a sustainably way”, he comments. Furthermore, these new species can be used for research in human health, like in the case of some fungi to be used for disease treatments.

At the CIAR, in the last few years, different types of species were collected: birds, lepidopterous – day and nocturnal butterflies -, spiders, scorpions, fish and shellfish, among others. For three years the scientists have worked assiduously on a project to study flying insects. They explained that they used a special collection method with Malaise traps which provided a lot of information that is being stored in a database for the IBOL project.

“The sampling technique is a standardized methodology used worldwide. The samples are taken with Malaise traps which capture flying insects through a fabric that intercepts them. We obtained weekly samples during the whole year, so we have a temporal pattern analysis that includes all seasons”, Schenone explains.

Avigliano provides support in terms of logistic and organization of the campaigns to transport the materials and accompany the researchers from Buenos Aires to Misiones. From there, together with the Ministerio de Ecología y Recursos Naturales Renovables de la Provincia de Misiones [Ministry of Ecology and Renewable Natural Resources of the Province of Misiones], he provides relevant information on the research they are conducting and the necessary legal documentation. If they are looking for certain animals, he tells them where they can find them and what legal permissions are needed, the different types of samples that can be collected, where to find food or water; and where to put the traps considering environmental issues like the temperature fluctuation and rains.

“The Malaise traps were invented 150 years ago and they are used by entomologists. The problem they have is that they collect so many specimens that it is very difficult for the researchers to analyze them and there is no practical way to study that material with traditional methods. Now, we can conduct the studies throughout the year and at an international level because everything that falls into the trap is sequenced at an industrial scale. For the first time, we have the capacity to process great numbers of specimens”, Tubaro adds.

In the case of the traps placed at the CIAR, so far, the scientists register the DNA barcode of thirty six thousands of species that belong to more than five thousand genetically distinct entities, also called Barcode Index Number (BIN), which is a surrogate measure of the number of species. This biodiversity is very high indeed worldwide because it is the sampling station that has captured more diversity, beating regions such as Malaysia and Costa Rica.

The scientists highlight that with this information they will be able to compare the biodiversity present from the northeast to the northwest of the country and complete the library of sequences of fauna species of Argentina, data that will be useful for specific studies.

“As a NGO linked to the care of natural environments, we think it is of utmost importance to be connected to science and technical organizations. They provide the concrete tools to develop functional strategies to work on the environment and reflect what happens in the area. The scope of this type of technologies and the advancement of inter institutional interaction is vital”, Schenone concludes.