11 research outputs found

    The Evolutionary Dynamics of the Lion Panthera leo Revealed by Host and Viral Population Genomics

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    The lion Panthera leo is one of the world's most charismatic carnivores and is one of Africa's key predators. Here, we used a large dataset from 357 lions comprehending 1.13 megabases of sequence data and genotypes from 22 microsatellite loci to characterize its recent evolutionary history. Patterns of molecular genetic variation in multiple maternal (mtDNA), paternal (Y-chromosome), and biparental nuclear (nDNA) genetic markers were compared with patterns of sequence and subtype variation of the lion feline immunodeficiency virus (FIVPle), a lentivirus analogous to human immunodeficiency virus (HIV). In spite of the ability of lions to disperse long distances, patterns of lion genetic diversity suggest substantial population subdivision (mtDNA ΦST = 0.92; nDNA FST = 0.18), and reduced gene flow, which, along with large differences in sero-prevalence of six distinct FIVPle subtypes among lion populations, refute the hypothesis that African lions consist of a single panmictic population. Our results suggest that extant lion populations derive from several Pleistocene refugia in East and Southern Africa (∼324,000–169,000 years ago), which expanded during the Late Pleistocene (∼100,000 years ago) into Central and North Africa and into Asia. During the Pleistocene/Holocene transition (∼14,000–7,000 years), another expansion occurred from southern refugia northwards towards East Africa, causing population interbreeding. In particular, lion and FIVPle variation affirms that the large, well-studied lion population occupying the greater Serengeti Ecosystem is derived from three distinct populations that admixed recently

    Pan-African Genetic Structure in the African Buffalo (Syncerus caffer): Investigating Intraspecific Divergence

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    The African buffalo (Syncerus caffer) exhibits extreme morphological variability, which has led to controversies about the validity and taxonomic status of the various recognized subspecies. The present study aims to clarify these by inferring the pan-African spatial distribution of genetic diversity, using a comprehensive set of mitochondrial D-loop sequences from across the entire range of the species. All analyses converged on the existence of two distinct lineages, corresponding to a group encompassing West and Central African populations and a group encompassing East and Southern African populations. The former is currently assigned to two to three subspecies (S. c. nanus, S. c. brachyceros, S. c. aequinoctialis) and the latter to a separate subspecies (S. c. caffer). Forty-two per cent of the total amount of genetic diversity is explained by the between-lineage component, with one to seventeen female migrants per generation inferred as consistent with the isolation-with-migration model. The two lineages diverged between 145 000 to 449 000 years ago, with strong indications for a population expansion in both lineages, as revealed by coalescent-based analyses, summary statistics and a star-like topology of the haplotype network for the S. c. caffer lineage. A Bayesian analysis identified the most probable historical migration routes, with the Cape buffalo undertaking successive colonization events from Eastern toward Southern Africa. Furthermore, our analyses indicate that, in the West-Central African lineage, the forest ecophenotype may be a derived form of the savanna ecophenotype and not vice versa, as has previously been proposed. The African buffalo most likely expanded and diverged in the late to middle Pleistocene from an ancestral population located around the current-day Central African Republic, adapting morphologically to colonize new habitats, hence developing the variety of ecophenotypes observed today

    Crops that feed the world 9. Oats- a cereal crop for human and livestock feed with industrial applications

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    Oats are a low input cereal widely grown across the world as both a grain and forage crop. Significant areas of production are in Northern Europe and North America and also in China and Australia. Although a traditional crop in many countries, in the last 50 years there has been a significant shift in oat production as a consequence of changing agricultural production and competition from other cereal crops. Oats are of significant economic importance for human consumption, for livestock feed and increasingly as a source of high value compounds with industrial applications as a consequence of the many unique properties of the oat grain. Traditional use in human diets in many countries has been boosted by the recent recognition of oats as a health food. This is attributed to the presence of β-glucan, the major endospermic cell wall polysaccharide. As a result, there has been an increase in the use of oats and a broadening of oat based products. Increasing knowledge of the composition of the oat grain and its value for the various end-users is leading to new opportunities for the crop. While the value of oats as a break crop in cereal based rotations is widely recognised, maintaining the profitability of the crop whilst meeting the needs of end users is essential for future production. Opportunities exist for plant breeders and agronomists to introduce new oat varieties with tailored agronomic approaches to address this challenge and to ensure the sustainability of oats for the future
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