Endangered, Creepy-Looking Aye-Aye's Genome Sequenced for First Time

Despite being a type of lemur, aye-ayes are far from looking cute and cuddly. With spider-like fingers and yellow eyes, this endangered, nocturnal primate calls Madagascar its home. In recent years, its population has steadily declined. Yet now, aye-ayes may be getting a little more help. Researchers have sequenced the complete genomes of three separate populations of these species in order to help guide conservation efforts.

The aye-aye was only recently re-classified as "endangered" by the International Union for the Conservation of Nature. Its natural forest habitat on Madagascar has been fragmented and destroyed--a serious issue considering that individual aye-ayes have huge home-range requirements.

"As forest patches become smaller, there is a particular risk that there won't be sufficient numbers of individual aye-ayes in a given area to maintain a population over multiple generations," said George H. Perry, one of the researchers, in a news release. This could mean drastic consequences for the future of the aye-aye.

Like rodents, these primates have continuously growing incisors. They use them to gnaw through the tough bark of dead trees, clinging onto the trunk with fingers and toes that are equipped with pointed claws. Then, they use their extra-long middle finger to extract insect larvae. They essentially fulfill the ecological role of a woodpecker.

In order to examine these fascinating creatures on a genetic level, researchers collected DNA samples from three separate regions of Madagascar in the north, east and west. The scientists then generated the complete genomes sequences of 12 individual aye-ayes and compared and analyzed the genomes of the three populations.

In the end, the researchers found that while eastern and western aye-ayes are genetically distinct, aye-ayes in the north and east show a much more significant amount of genetic distance. This actually pointed to the fact that the aye-ayes have not interbred between the populations of these regions for quite some time.  

But how long had it been since they interbred? In order to find this out, the scientists compared aye-aye genetic diversity to present-day human genetic diversity. They gathered 12 complete human DNA sequences from publicly available databases for three distinct human populations. Then, the team developed software to compare the human sequences to the aye-aye sequences. Surprisingly, they found that present-day African and European populations were genetically more similar than northern and eastern aye-aye populations. Essentially, the aye-ayes had been separated for a large amount of time and should be protected by conservation efforts accordingly.

The findings could be used to help better protect the species. In particular, it reveals the genetic diversity that the aye-ayes possess.

"This work highlights an important region of aye-aye biodiversity in northern Madagascar, and this unique biodiversity is not preserved anywhere except in the wild," said Edward Louis, one of the researchers, in a news release. "There is a tremendous historical loss of habitat in northern Madagascar that is continuing at an unsustainable rate today."

The results of this sequencing were published in an early edition of the Proceedings of the National Academy of Sciences online.