Chimpanzee (Pan troglodytes) young female, digging with stick, Nairobi, Kenya, AfricaCredit: Peter Davey/FLPA/Alamy Stock Photo
A new study published in the journal Cell Genomics has revealed genomic secrets from the faeces of endangered African chimpanzees that may help in their conservation.
Claudia Fontsere, postdoctoral researcher on conservation at the Institute of Evolution Biology, Barcelona, and colleagues from Senegal, Ghana, Germany and Switzerland, collected 800 faecal samples from 48 locations across Africa. This was part of work with the Pan-African Programme: The Cultured Chimpanzee.
“We were able to build the most extensive catalogue of genomic diversity in wild chimpanzee populations,” Claudia said. The data could contribute to conservation efforts by providing needed information about the genetics of this endangered species.
With this dataset, the team was able to link historical population structures and flow of genes between chimpanzee populations with geographical barriers. This includes rivers like Sanaga in Cameroon and Ogooue in Democratic Republic of Congo and lakes such as Lake Tanganyika.
“We have also designed a geolocation methodology that is able to infer the unknown origin of confiscated chimpanzees to around 100 kilometres from their apparent origin. This will support efforts to combat illegal trade in wildlife and wildlife products,” Claudia said.
Different and variable genomic samples of chimpanzee populations act as a trove to help scientists learn about their complete past demographic history, connectivity and genetic diversity.
This is especially true for places across the chimpanzee range in tropical Africa where there’s lack of preserved archaeological material. “Just by our sampling method, we have discovered around 50 percent more genetic variants on chromosome 21 than previous studies,” Claudia said.
Obtaining invasive samples, such as blood or tissue, for genome sequencing of wild endangered species would usually yield higher quality DNA samples. But this is not feasible—or even desirable—for a number of reasons, the researchers explained. “This is why in this study we have used non-invasive samples, as their collection does not involve any contact with the animals.”
Faecal samples, however, come with many technical challenges, mainly due to their low proportions of highly degraded host DNA, usually around 1-3 percent.
