Browsing by Author "Eizirik, Eduardo"

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    Phylogenomics of the world's otters
    (2022) de Ferran, Vera; Figueiro, Henrique Vieira; Trindade, Fernanda de Jesus; Smith, Oliver; Sinding, Mikkel-Holger S.; Trinca, Cristine S.; Lazzari, Gabriele Zenato; Veron, Geraldine; Vianna, Juliana A.; Barbanera, Filippo; Kliver, Sergei; Serdyukova, Natalia; Bulyonkova, Tatiana; Ryder, Oliver A.; Gilbert, M. Thomas P.; Koepfli, Klaus-Peter; Eizirik, Eduardo
    Comparative whole-genome analyses hold great power to illuminate commonalities and differences in the evolution of related species that share similar ecologies. The mustelid subfamily Lutrinae includes 13 currently recognized extant species of otters,(1-5) a semiaquatic group whose evolutionary history is incompletely understood. We assembled a dataset comprising 24 genomes from all living otter species, 14 of which were newly sequenced. We used this dataset to infer phylogenetic relationships and divergence times, to characterize patterns of genome-wide genealogical discordance, and to investigate demographic history and current genomic diversity. We found that genera Lutra, Aonyx, Amblonyx, and Lutrogale form a coherent clade that should be synonymized under Lutra, simplifying the taxonomic structure of the subfamily. The poorly known tropical African Aonyx congicus and the more widespread Aonyx capensis were found to be reciprocally monophyletic (having diverged 440,000 years ago), supporting the validity of the former as a distinct species. We observed variable changes in effective population sizes over time among otters within and among continents, although several species showed similar trends of expansions and declines during the last 100,000 years. This has led to different levels of genomic diversity assessed by overall heterozygosity, genome-wide SNV density, and run of homozygosity burden. Interestingly, there were cases in which diversity metrics were consistent with the current threat status (mostly based on census size), highlighting the potential of genomic data for conservation assessment. Overall, our results shed light on otter evolutionary history and provide a framework for further in-depth comparative genomic studies targeting this group.
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    Phylogeography and Demographic History of the Neotropical Otter (Lontra longicaudis)
    (OXFORD UNIV PRESS INC, 2012) Trinca, Cristine S.; de Thoisy, Benoit; Rosas, Fernando C. W.; Waldemarin, Helen F.; Koepfli, Klaus Peter; Vianna, Juliana A.; Eizirik, Eduardo
    The Neotropical otter (Lontra longicaudis) is a medium-sized semiaquatic carnivore with a broad distribution in the Neotropical region. Despite being apparently common in many areas, it is one of the least known otters, and genetic studies on this species are scarce. Here, we have investigated its genetic diversity, population structure, and demographic history across a large portion of its geographic range by analyzing 1471 base pairs (bp) of mitochondrial DNA from 52 individuals. Our results indicate that L. longicaudis presents high levels of genetic diversity and a consistent phylogeographic pattern, suggesting the existence of at least 4 distinct evolutionary lineages in South America. The observed phylogeographic partitions are partially congruent with the subspecies classification previously proposed for this species. Coalescence-based analyses indicate that Neotropical otter mitochondrial DNA lineages have shared a rather recent common ancestor, approximately 0.5 Ma, and have subsequently diversified into the observed phylogroups. A consistent scenario of recent population expansion was identified in Eastern South America based on several complementary analyses of historical demography. The results obtained here provide novel insights on the evolutionary history of this largely unknown Neotropical mustelid and should be useful to design conservation and management policies on behalf of this species and its habitats.