Metabarcoding analysis of arthropod diversity in the rainforest of Mexico

Los Tuxtlas Biosphere reserve in Mexico, harbors the northernmost neotropical rainforest, an ecosystem that once covered southern Mexico and Central America. Immersed in a complex socio ecological context, the Los Tuxtlas region has lost most of its original vegetation due to human activities. Thus, it is essential to obtain a baseline of the remaining arthropod diversity to evaluate the impact of anthropogenic disturbances and conservation and restoration efforts. In this project we want to test the suitability of metabarcoding approaches to uncover arthropod diversity and to detect changes in community composition in the rain and dry seasons. First, we compiled species lists from the literature and scientific collections to have a taxonomic framework to compare against. Despite being one of the best studied areas in Mexico, this compilation had not been done before. Using this information, we assessed the representability of arthropod taxa in BOLD system and NCBI databases to quantify the gap in genetic information for these groups. Additionally, we collected bulk samples with three methods: Berlesse funnel, Malaise and light traps, in three sites at three different altitudes within the reserve. We employed non-destructive DNA extraction methods followed by PCR amplification of a COI gene fragment for Illumina sequencing. Our first analyses detected 1567 ASVs, however taxonomic assignment at the genus level was successful for only 52 of them. These results highlight the urge to continue generating reference sequences for rainforest arthropods. In the meantime, metabarcoding can be applied to obtain an image of current arthropod diversity.