RESUMO
Reset osmostat (RO) consists of a change in the normal plasma osmolality threshold (reduction or increase), which consequently induces chronic dysnatremia (hyponatremia or hypernatremia). Although the early papers on RO state that hyponatremic patients with this condition are usually not symptomatic, the current view is that most patients with hyponatremia are symptomatic and should be treated. RO has been associated with a myriad of clinical conditions and has clear diagnostic criteria which are crucial to arrive at the correct diagnosis and treatment.
RESUMO
Here, we investigate the evolutionary history and pattern of genetic divergence in the Rhagoletis pomonella (Diptera: Tephritidae) sibling species complex, a model for sympatric speciation via host plant shifting, using 11 anonymous nuclear genes and mtDNA. We report that DNA sequence results largely coincide with those of previous allozyme studies. Rhagoletis cornivora was basal in the complex, distinguished by fixed substitutions at all loci. Gene trees did not provide reciprocally monophyletic relationships among US populations of R. pomonella, R. mendax, R. zephyria and the undescribed flowering dogwood fly. However, private alleles were found for these taxa for certain loci. We discuss the implications of the results with respect to identifiable genetic signposts (stages) of speciation, the mosaic nature of genomic differentiation distinguishing formative species and a concept of speciation mode plurality involving a biogeographic contribution to sympatric speciation in the R. pomonella complex.