A new paper published by Oxford University Press in the journal Molecular Biology and Evolution provides the first comprehensive genome resource for the pangolin, also known as the scaly anteater. Pangolins are found in Asia and sub-Saharan Africa and are the only mammals covered in scales. Trafficked in large quantities for their meat and alleged medicinal properties, the animals are also on the verge of extinction due to widespread deforestation in their native habitat.
Pangolins, which consist of eight extant species, have attracted great public attention in recent years, and conservation efforts are ongoing. This is largely because pangolins are the most trafficked wild mammals on the planet, and it has recently been suggested that they may be linked to the COVID-19 pandemic (which is, of course, incorrect).
The significance of pangolin genomics
Despite the critical conservation situation of pangolins, they are still under-researched and there are still large gaps in basic species or population research. Researchers are now paying increasing attention to genomics in wildlife studies because genomics provides data that can more accurately understand the division of species or populations, population information, diversity, historical trajectories, and the ability of animals to adapt to global changes. Not to mention its potential for tracing the origins of illegally traded individuals in order to better identify poaching hotspots and disrupt trafficking networks.
A recent article published in the journal Molecular Biology and Evolution provides a comprehensive genome database for pangolins, which is crucial for their conservation. Pangolins are the most trafficked wild mammals in the world. They are found in Asia and Africa and face constant threats from hunting and habitat destruction. This study, which has historically understudied pangolins, fills a major gap by sequencing multiple pangolin species and even identifies a potential new species. Image source: DarrenPietersen/"Molecular Biology and Evolution"
Challenges facing pangolin genome research
Obtaining pangolin genome-wide information is a challenging task. First, the geographical isolation between pangolin species and the limited fossil record pose methodological obstacles. Pangolin species in Asia and Africa diverged approximately 37.9 million years ago, so it's difficult to truly understand the evolution of pangolin groups using reference genomes from distant species. Second, pangolins’ elusive behavior and tropical distribution make genetic sampling expensive and time-consuming.
Research results and significance
The researchers sequenced, assembled and annotated the first reference genome of the giant pangolin native to Africa, as well as the genomes of the black-bellied pangolin, South African pangolin, Indian pangolin and Philippine pangolin. These new genomic data, along with previously published information on the remaining three species - the white-bellied pangolin, the Sunda pangolin and the Chinese pangolin - provide the first complete pangolin genome. In the process, the researchers also discovered a potential new pangolin species from previously published genomic data.
The researchers believe this information will ultimately provide a complete picture of how pangolins evolve over time in response to changing environmental conditions, providing important information on how to effectively protect these animals through conservation priorities and management plans in the coming years. The findings will also help develop DNA toolkits to track the pangolin trade.
Sean Heighton, one of the authors of the paper, said: "The collaborative approach of the authors of this study, who come from Africa, Asia and Europe, allows us for the first time to delve into the evolution of pangolins in all eight species from a genome-wide perspective. We hope that these genomes will form the basis for further genetic research to help protect these animals."