Pontoporia blainvillei (Gervais & d’Orbigny, 1844), the franciscana dolphin, is the most endangered small cetacean in the Western South Atlantic. It is an endemic species with a coastal and estuarine distribution that has been divided into four Franciscana Management Areas (FMAs). We used the mitochondrial DNA control region to conduct a phylogeographic analysis to evaluate the population structure of the franciscana and the influence of paleoceanographic events on its biogeographic history. We found nine populations along the entire distribution (ΦST?=?0.41, ΦCT?=?0.38, p?<?10–5), with estimated migration rates resulting in less than one female per generation. Populations from FMAIII and FMAIV in the south (including the Río de La Plata Estuary) showed higher long-term migration rates and effective population sizes than northern populations. The phylogeographic analysis supports the franciscana origin in the Río de La Plata Estuary, with further dispersal south and northwards. The first lineage split happened around 2.5 Ma, with lineage radiation throughout the Pleistocene until recent fragmentation events shaped current-day populations. We suggest that Pleistocene glaciations influenced the dispersion and population structure of the franciscana. Specifically, that the shift of the Brazil-Malvinas Confluence drove the dispersion northwards. Then, low sea-level periods caused either the isolation in estuarine refugia or local extinctions, followed by re-colonizations.
New onset of diabetes is associated with the use of statins. We have recently demonstrated that pravastatin-treated hypercholesterolemic LDL receptor knockout (LDLr−/−) mice exhibit reductions in insulin secretion and increased islet cell death and oxidative stress. Here, we hypothesized that these diabetogenic effects of pravastatin could be counteracted by treatment with the antioxidant coenzyme Q 10 (CoQ 10), an intermediate generated in the cholesterol synthesis pathway. LDLr −/− mice were treated with pravastatin and/or CoQ 10 for 2 months. Pravastatin treatment resulted in a 75% decrease of liver CoQ 10 content. Dietary CoQ 10 supplementation of pravastatin-treated mice reversed fasting hyperglycemia, improved glucose tolerance (20%) and insulin sensitivity (>2-fold), and fully restored islet glucose-stimulated insulin secretion impaired by pravastatin (40%). Pravastatin had no effect on insulin secretion of wild-type mice. In vitro, insulin-secreting INS1E cells cotreated with CoQ 10 were protected from cell death and oxidative stress induced by pravastatin. Simvastatin and atorvastatin were more potent in inducing dose-dependent INS1E cell death (10–15-fold), which were also attenuated by CoQ 10 cotreatment. Together, these results demonstrate that statins impair β-cell redox balance, function and viability. However, CoQ 10 supplementation can protect the statins detrimental effects on the endocrine pancreas. 相似文献
Species-specific disturbance calls of five commercially-important characiform species are described, the Curimatidae commonly called branquinhas: Potamorhina latior, Potamorhina altamazonica and Psectrogaster amazonica; Prochilodontidae: jaraquí Semaprochilodus insignis and curimatã Prochilodus nigricans. All species have a two-chambered swimbladder and the sonic mechanism, present exclusively in males, utilises hypertrophied red muscles between ribs that adhere to the anterior chamber. The number of muscles is unusually plastic across species and varies from 1 to 4 pairs suggesting considerable evolution in an otherwise conservative system. Advertisement calls are produced in river confluences in the Madeira Basin during the high-water mating season (January–February). Disturbance calls and sampling allowed recognition of underwater advertisement choruses from P. latior,S. insignis and P. nigricans. The advertisement calls of the first two species have largely similar characteristics and they mate in partially overlapping areas in the Guaporé River. However, P. latior sounds have a lower dominant frequency and it prefers to call from river confluences whereas S. insignis shoals occur mostly in the main river channel adjacent to the confluence. These results help identify and differentiate underwater sounds and evaluate breeding areas during the courtship of commercially important characids likely to be affected by two hydroelectric dams. 相似文献
Plant Cell, Tissue and Organ Culture (PCTOC) - Olive is one of the most important oil tree crop worldwide and great attention is paid on its genetic improvement. Although different breeding... 相似文献
Journal of Mathematical Biology - In this paper we consider Susceptible $$\rightarrow $$ Infectious $$\rightarrow $$ Recovered (SIR) epidemics on random graphs with clustering. To incorporate group... 相似文献
Recent years have seen an increasing interest in individual behavioral variation. However, the implications of such variation for population dynamics are often unknown. We studied the dynamics of a bottlenose dolphin (Tursiops truncatus gephyreus) population from southern Brazil, where some individuals forage cooperatively with artisanal fishermen. We fitted mark‐recapture models to 10 yr of photo‐identification data to investigate the influence of this foraging specialization on dolphins’ population parameters, controlling for sex and ranging behavior. We estimated adult survival to be high (0.949 ± 0.015 SE), weakly influenced by home range size, sex or the frequency of interaction with fishermen. The slightly higher survival probability for individuals with smaller home ranges could stem from the benefits of reduced spatial requirements implied by the specialized foraging. Foraging also influenced the probability of resighting individuals, and there was no temporary or permanent emigration. Abundance fluctuated slightly over the years from 54 (95% CI = 49–59) to 60 (95% CI = 52–69) individuals, with no evident population trend. Despite such apparent population stability, we confirm this population remains small and geographically isolated which may threaten its viability and the viability of its unusual, localized foraging specialization. Our study also illustrates how accounting for individual variation can portray animal population dynamics more realistically. 相似文献
Colorectal cancer (CRC) is a high‐incidence malignancy worldwide which still needs better therapy options. Therefore, the aim of the present study was to investigate the responses of normal or malignant human intestinal epithelium to bone morphogenetic protein (BMP)‐9 and to find out whether the application of BMP‐9 to patients with CRC or the enhancement of its synthesis in the liver could be useful strategies for new therapy approaches. In silico analyses of CRC patient cohorts (TCGA database) revealed that high expression of the BMP‐target gene ID1, especially in combination with low expression of the BMP‐inhibitor noggin, is significantly associated with better patient survival. Organoid lines were generated from human biopsies of colon cancer (T‐Orgs) and corresponding non‐malignant areas (N‐Orgs) of three patients. The N‐Orgs represented tumours belonging to three different consensus molecular subtypes (CMS) of CRC. Overall, BMP‐9 stimulation of organoids promoted an enrichment of tumour‐suppressive gene expression signatures, whereas the stimulation with noggin had the opposite effects. Furthermore, treatment of organoids with BMP‐9 induced ID1 expression (independently of high noggin levels), while treatment with noggin reduced ID1.In summary, our data identify the ratio between ID1 and noggin as a new prognostic value for CRC patient outcome. We further show that by inducing ID1, BMP‐9 enhances this ratio, even in the presence of noggin. Thus, BMP‐9 is identified as a novel target for the development of improved anti‐cancer therapies of patients with CRC. 相似文献