Lion Evolutionary History-Host and Viral Population Genomics

Panthera leo or the lion, is the most iconic of the Pantherines, with the earliest fossils from Africa dating back to about 2-1.5 million years ago (Antunes et.al. 2008). Lions had the greatest intercontinental distribution for a large land mammal, excluding humans, by the Late Pleistocene approximately 130,000-10,000 years ago (Antunes et.al. 2008). Their geographic range was very wide spread until their extinction from Europe 2,000 years ago and Eurasia and North Africa 150 years ago limiting them to sub-Saharan Africa and the Gir Forest in India (see Figure 1). In species of modern felids, large multigenic data sets are required due to their generally rapid and very recent speciation, and our knowledge of lion evolutionary history has mostly been hindered by the lack of appropriate genetic markers (Antunes et.al. 2008). A recent investigation has used host and virus genetic information of infectious disease outbreaks in lions and our knowledge of their unique social ecology to enhance our understanding of the evolutionary history of Panthera leo.

 

 Figure 1. Geographic location of lion samples and the variability of host and viral genetic markers among the lion populations (Antunes et.al. 2008).


Unlike other felids species, lions have a cooperative social system and many populations have high frequencies of feline immunodeficiency virus (FIV). This retrovirus integrates into the host genome, being transferred by cell-to-cell contact such as fighting and mating (Antunes et.al. 2008). Viral dissemination could then be used to measure the frequency of contact between infected and healthy lions among populations. The virus is also genetically diverse in lions which acted as an unusual marker for studying ongoing demographic processes in the large felid species (Antunes et.al. 2008). Variation in common genetic markers were compared with FIV sequence and subtype variation to find that African lions do not consist of a single panmictic population, as previously hypothesised, and that despite Panthera leo's ability to disperse over long distances, the species is experiencing population subdivision and reduced gene flow (Antunes et.al. 2008). Results showed that current lion populations derived from eastern and southern Africa in the Pleistocene with a second expansion during the Pleistocene/Holocene transition into northern parts of Africa causing population interbreeding. Antunes et.al. (2008) also found that the lion population occupying the Serengeti ecosystem in eastern Africa derives from three distinct populations that admixed quite recently.

References:
  • Antunes, A, Troyer, JL, Roelke, ME, Pecon-Slattery, J, Packer, C, Winterbach, C, Winterbach, H, Hemson, G, Frank, F, Stander, P, Siefert, L, Driciru, M, Funston, PJ, Alexander, KA, Prager, KC, Mills, G, Wildt, D, Bush, M, O’Brien, SJ & Johnson, WE 2008, 'The Evolutionary Dynamics of the Lion Panthera leo Revealed by Host and Viral Population Genomics', PLoS Genetics, vol. 4, no. 11, viewed 18 May 2015, doi:10.1371/journal.pgen.1000251.

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