Polymorphic Y chromosomes harbor cryptic variation with manifold functional consequences

The paucity of polymorphisms in single-copy genes on the Y chromosome of Drosophila contrasts with data indicating that this chromosome has polymorphic phenotypic effects on sex ratio, temperature sensitivity, behavior, and fitness. We show that the Y chromosome of D. melanogaster harbors substantial genetic diversity in the form of polymorphisms for genetic elements that differentially affect the expression of hundreds of X-linked and autosomal genes. The affected genes are more highly expressed in males, more meagerly expressed in females, and more highly divergent between species. Functionally, they affect microtubule stability, lipid and mitochondrial metabolism, and the thermal sensitivity of spermatogenesis. Our findings provide a mechanism for adaptive phenotypic variation associated with the Y chromosome.     

Organic and Conventional <Emphasis Type="Italic">Coffea arabica</Emphasis> L.: A Comparative Study of the Chemical Composition and Physiological,Biochemical and Toxicological Effects in Wistar Rats

Differentiation between organic and conventional coffee has increased due to the growing demand and high consumption of healthy foods that contain compounds with antioxidant potential, which have been associated with the reduction of chronic diseases. We used organic and conventional coffee in powder 4% (w/w) and infusions 5%, 10% and 20% (w/v) incorporated in a commercial diet to test in vivo. The levels of chlorogenic acid, caffeine and trigonelline were determined by high performance liquid chromatography. The body weight, weight gain, food consumption, aberrant foci crypt, mucin depleted foci, stress biomarkers protein carbonyl and malondialdehyde, biochemical parameters and behavior of the rats were compared between the experimental and control groups within a framework of colon carcinogenesis. The organic coffee showed higher levels of chlorogenic acid, caffeine and trigonelline than conventional, however, this difference did not significantly affect behavior. The infusions had an antioxidant effect, reducing the levels of malondialdehyde; however, the biochemical parameters of the serum were not altered, and there was neither induction nor prevention of preneoplasic lesions.     

Dam cascade in run-of-river systems promotes homogenisation of fish functional traits in a plateau river

Impoundments caused by dams are often responsible for intense changes in physical, chemical, geomorphological and hydrological characteristics of rivers, and are one of the main causes in global freshwater biodiversity declines. When these changes derive from multiple cascading dams, the cumulative effect can amplify, causing more pronounced consequences than each individual reservoir, which may affect, among other factors, the biotic and functional conditions of fish fauna. We aim to evaluate the impact of dam cascades on fish functional diversity by applying trait-based analysis. We evaluate the functional attributes (functional indices and community-weighted means of trait values) and environmental variables at 11 sites, which encompassed different segments affected by the hydroelectric plants (transition, reservoir, reduced discharge section and tributary) in the Antas River Basin dam cascade system located in southern Brazil. The spatial differences of the functional indices (richness, evenness, divergence, dispersion and diversity) as well as the weighted averages of each functional trait were tested through analysis of variance. The most affected functional characteristics were those related to habitat exploration by detritivorous species, especially the use of food resources and body shape, as well as the type of swimming movement. These traits were more representative at the most downstream site of the complex. Thus, our results suggest that the cascade of dams acts in the functional homogenisation of the ichthyofauna in the intermediate stretches, mainly reflecting physical changes in habitat.