Pangolins are one of the most unique mammal species with their scaly exterior and ant-eating diet. To date there are eight known and recognised species distributed onto two continents, Africa and Asia.
Pangolins are one of the most illegally traded mammal species on the black market with numbers exceeding those of the illegal trade in rhino, elephant and tiger products. They are victims of habitat destruction, electrocution on game farm fences, bushmeat and traditional medicine.
The four African pangolin species are listed as Vulnerable on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species and include Temminck’s ground pangolin (Smutsia temminckii), giant ground pangolin, (Smutsia gigantean), the white-bellied tree pangolin (Phataginus tricuspis) and black-bellied tree pangolin (Phataginus tetradactyla).
Of the four Asian species, two are listed as Critically Endangered – the Chinese pangolin (Manis pentadactyla) and the Malayan pangolin (Manis javanica) and two are listed as Endangered – Philippine pangolin (Manis culionensis) and Indian pangolin (Manis crassicaudata).
However in 2016, the IUCN voted in support of transferring all eight pangolin species from Appendix II to Appendix I of the Convention on International Trade in Endangered Species of Fauna and Flora (CITES), which was approved at the 17th Conference of Parties (COP17). The listing has resulted in worldwide commercial trade in pangolins being banned.
To date, very little information exists on the ecology, behaviour, population structure and genome of most of the species. However, recently the whole genome of the two Asian species’ pangolins were sequenced and annotated. Although this was performed in Malaysia, the National Zoological Gardens of South Africa’s (NZG) Department of Research and Scientific Services has used modern sequencing technology to generate whole genome data from all four African pangolin species.
The NZG assembled the data and compared the mitochondrial DNA among species. Specific markers are being designed and tested to perform geo-referencing in the southern African pangolins by determining the population structures present in pangolin populations. This will aid in determining the origin of confiscated pangolin samples or individuals in order to release them back to the correct habitat niches from which they emanated.
The next generation sequencing data from the African pangolin species along with the Asian genome annotations gave us the first insights into the molecular structure of the pangolins which will lead to further investigate and uncover all the hidden secrets in the different pangolin species. As part of a larger study of genome variation in pangolins globally, understanding the genome structure and gene functions in the pangolin, it will aid in better conservation planning and strategies for these animals as well as understanding their population structures and differences.
By: Zelda du Toit, Dr Desiré Dalton, Prof Antoinette Kotzé, NZG Department of Research and Scientific Services