• Cara Brook

Don’t be duped by Eidolon dupreanum!

Today we release the genome of the third and last of the three species of Old World Fruit Bat endemic to the island of Madagascar: Eidolon dupreanum.

Eidolon dupreanum. Photo by Cara Brook.

Bats (order: Chiroptera) make up more than one-fifth of mammalian diversity, and they can broadly be classed into two major sub-orders: the largely insectivorous and small-bodied Yangochiropterans—which typically echolocate to catch insect prey and are distributed widely across both the New and the Old Worlds—and the larger-bodied Yinpterochiropterans, including those in the family Pteropodidae (previously known as the ‘megabats’), which use sight and smell to track down fruit and nectar resources. Pteropodids are found only in Africa, Asia, and Australia.


The International Union for the Conservation of Nature classes some 35% of pteropodids under some category of threat, more than three times that of all other bat species combined [1]. These large fruit bats are particularly vulnerable to habitat destruction and land conversion and are also disproportionately hunted as a source of human food. As a result of higher human-bat contact rates resulting from human hunting and fruit bat consumption of domestic crops, Yinpterochiropterans bats have played important roles in the emergence of several recent viruses known to infect humans, including SARS-CoV-2, the cause of COVID-19, which is derived from Rhinolophous spp. horseshoe bats in China.

Eidolon dupreanum. Photo by Cara Brook.

On the Indian Ocean island nation of Madagascar, my team of young researchers, ‘Ekipa Fanihy’ (‘Team Fruit Bat’ in Malagasy), studies three species of pteropodid found nowhere else on Earth: Pteropus rufus, Rousettus madagascariensis, and Eidolon dupreanum. With this final release, we’ve now worked with DNA Zoo to construct genomes for all three endemic pteropodids on the island. (Read the blog posts for P. rufus and R. madagascariensis on dnazoo.org here and here!)


Eidolon dupreanum is noteworthy for being the only known sister species to the famous African Straw-Colored Fruit Bat, Eidolon helvum, which is distributed widely across the African continent and demonstrates the largest panmictic range ever described for any non-marine mammal [2]. (See the chromosome-length upgrade for Eidolon helvum from (Parker et al., 2013) on DNA Zoo website, here!) Sub-populations of E. helvum from Ghana to Kenya to Malawi demonstrate no genetic structure, a reflection of this species’ huge migratory capacity, with important implications for understanding zoonotic threats posed by the fruit bat virome to human communities.


While less is known about the sister species, Eidolon dupreanum, population genetic studies suggest that this bat is also largely panmictic across the Madagascar island but don’t be duped into thinking that these bats are the same! Eidolon dupreanum is highly genetically distinct from E. helvum, with estimates of species divergence times dating back to the mid- to late-Miocene—some ten to five million years ago [3]. Indeed, the two species show considerable dimorphism in size, color, and ecology—with E. dupreanum roosting in caves and crevasses, while E. helvum roosts in large congregations in trees [4]. Other recent work is beginning to shed light on the importance of E. dupreanum for dispersal of native fruit species in Madagascar [5], as well as highlight hunting threats to its population viability [6]. With DNA Zoo, we are excited to contribute one more piece of evidence to the growing knowledge base for this rare and important pteropodid species!

Assembly of this genome was financed by an NIH grant (R01-AI129822-01) administered Dr. Cara Brook of UC Berkeley and Dr. Jean-Michel Héraud of Institut Pasteur of Madagascar (link: http://grantome.com/grant/NIH/R01-AI129822-01).

Bibliography

[1] C.C. Voigt, T. Kingston, Bats in the Anthropocene: Conservation of bats in a changing world, 2016. doi:10.1007/978-3-319-25220-9.

[2] A.J. Peel, D.R. Sargan, K.S. Baker, D.T.S. Hayman, J. a Barr, G. Crameri, R. Suu-Ire, C.C. Broder, T. Lembo, L.-F. Wang, A.R. Fooks, S.J. Rossiter, J.L.N. Wood, A. a Cunningham, Continent-wide panmixia of an African fruit bat facilitates transmission of potentially zoonotic viruses, Nat. Commun. 4 (2013) 2770. doi:10.1038/ncomms3770.

[3] J.J. Shi, L.M. Chan, A.J. Peel, R. Lai, A.D. Yoder, S.M. Goodman, A deep divergence time between sister species of Eidolon (Pteropodidae) with evidence for widespread panmixia, Acta Chiropterologica. 16 (2014) 279–292. doi:10.3161/150811014X687242.

[4] A.O. Kamins, O. Restif, Y. Ntiamoa-Baidu, R. Suu-Ire, D.T.S. Hayman, a a Cunningham, J.L.N. Wood, J.M. Rowcliffe, Uncovering the fruit bat bushmeat commodity chain and the true extent of fruit bat hunting in Ghana, West Africa., Biol. Conserv. 144 (2011) 3000–3008. doi:10.1016/j.biocon.2011.09.003.

[5] M. Picot, R.K.B. Jenkins, O. Ramilijaona, P.A. Racey, S.M. Carrie, The feeding ecology of Eidolon dupreanum (Pteropodidae) in eastern Madagascar, Afr. J. Ecol. 45 (2007) 645–650. doi:10.1111/j.1365-2028.2007.00788.x.

[6] C.E. Brook, H.C. Ranaivoson, D. Andriafidison, M. Ralisata, J. Razafimanahaka, J. Héraud, A.P. Dobson, C.J. Metcalf, Population trends for two Malagasy fruit bats, Biol. Conserv. 234 (2019) 165–171. doi:10.1016/j.biocon.2019.03.032.

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