Cryptic lineage differentiation among Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the northwest Indian Ocean.

Phylogeography can provide insight into the potential for speciation and identify geographic regions and evolutionary processes associated with species richness and evolutionary endemism. In the marine environment, highly mobile species sometimes show structured patterns of diversity, but the processes isolating populations and promoting differentiation are often unclear. The Delphinidae (oceanic dolphins) are a striking case in point and, in particular, bottlenose dolphins (Tursiops spp.). Understanding the radiation of species in this genus is likely to provide broader inference about the processes that determine patterns of biogeography and speciation, because both fine-scale structure over a range of kilometers and relative panmixia over an oceanic range are known for Tursiops populations. In our study, novel Tursiops spp. sequences from the northwest Indian Ocean (including mitogenomes and two nuDNA loci) are included in a worldwide Tursiops spp. phylogeographic analysis. We discover a new 'aduncus' type lineage in the Arabian Sea (off India, Pakistan and Oman) that diverged from the Australasian lineage ∼261 Ka. Effective management of coastal dolphins in the region will need to consider this new lineage as an evolutionarily significant unit. We propose that the establishment of this lineage could have been in response to climate change during the Pleistocene and show data supporting hypotheses for multiple divergence events, including vicariance across the Indo-Pacific barrier and in the northwest Indian Ocean. These data provide valuable transferable inference on the potential mechanisms for population and species differentiation across this geographic range.

Phylogenomics of the killer whale indicates ecotype divergence in sympatry.

For many highly mobile species, the marine environment presents few obvious barriers to gene flow. Even so, there is considerable diversity within and among species, referred to by some as the 'marine speciation paradox'. The recent and diverse radiation of delphinid cetaceans (dolphins) represents a good example of this. Delphinids are capable of extensive dispersion and yet many show fine-scale genetic differentiation among populations. Proposed mechanisms include the division and isolation of populations based on habitat dependence and resource specializations, and habitat release or changing dispersal corridors during glacial cycles. Here we use a phylogenomic approach to investigate the origin of differentiated sympatric populations of killer whales (Orcinus orca). Killer whales show strong specialization on prey choice in populations of stable matrifocal social groups (ecotypes), associated with genetic and phenotypic differentiation. Our data suggest evolution in sympatry among populations of resource specialists.

Post-transplantation weight gain: prevalence and the impact of steroid-free therapy.

INTRODUCTION: Weight gain after renal transplantation has a multifactorial etiology, which can be associated with complications such as hypertension, dyslipidemia and diabetes, with a probable impact on cardiovascular morbidity and mortality post-transplantation. OBJECTIVE: The objectives of this study were to investigate the prevalence of weight gain and obesity post-transplantation among renal recipients of a hospital and to evaluate the impact of immunosuppressive therapy without steroids. MATERIALS AND METHODS: We have evaluated all patients who had kidney transplantations performed between January 2005 and December 2009 at General Hospital of Fortaleza, who were older than 18 years of age and had at least 12 months of follow-up post-transplantation. Overweight was defined as body mass index (BMI) between 25 and 30 kg/m(2) and obesity >30 kg/m(2). The association between weight gain and the following variables was investigated: age and gender of the recipient and the donor, donor type, steroid use, presence of systemic arterial hypertension (SAH) and diabetes mellitus, creatinine, glucose, cholesterol, and triglycerides. RESULTS: The study population included 203 recipients; 59.5% were males, their mean age systemic arterial hypertension (SAH) was 37 years, and 64.2% had deceased donors. In regard to immunosuppression, 41.3% made use of steroids. After 36 months of follow-up, the average weight gain was 6.6 kg in relation to the first month post-transplantation. Among the variables studied, the recipient's younger age and female gender, the younger donor, and the creatinine level were associated with greater weight gain after 36 months of transplantation. CONCLUSION: The percentage of weight gain was on average 9% after 36 months post-transplantation, although the prevalence of overweight and obesity increased significantly in the same period. The use of steroid therapy had no impact on the percentage of weight gain post-transplantation, and association was observed only between the younger age and the female gender of the recipient, the younger donor age, and the creatinine level with the highest weight gain post-transplantation.

Atypical panmixia in a European dolphin species (Delphinus delphis): implications for the evolution of diversity across oceanic boundaries.

Despite the scarcity of geographical barriers in the ocean environment, delphinid cetaceans often exhibit marked patterns of population structure on a regional scale. The European coastline is a prime example, with species exhibiting population structure across well-defined environmental boundaries. Here we undertake a comprehensive population genetic study on the European common dolphin (Delphinus delphis, based on 492 samples and 15 loci) and establish that this species shows exceptional panmixia across most of the study range. We found differentiation only between the eastern and western Mediterranean, consistent with earlier studies, and here use approximate Bayesian computations to explore different scenarios to explain the observed pattern. Our results suggest that a recent population bottleneck likely contributed significantly to the differentiation of the Eastern Mediterranean population (in Greek waters). This interpretation is consistent with independent census data that suggest a sharp population decline in the recent past. The implication is that an unperturbed population may currently show panmixia across the full study range. This exception to the more typical pattern of population structure seen for other regional dolphin species (and for common dolphin populations elsewhere in the world) suggests particular ecological or life-history traits distinct to this species in European waters.