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Flight is one of the most effective yet energetically demanding means of movement. Its energy costs are normally associated with interspecific variation in efficiency, size of organs, and physiological systems that reflect different flight capacities. Adaptive morphological variation may be constrained by physical demands that vary with body size, but work remains to place allometry associated with flight mode in an ecological and evolutionary context. We predicted that heart, lung, and skeletal masses, as well as tracheal diameter, should show a reciprocal positive correlation and have reduced size in species with poor flight capacities. We measured tracheal diameter together with lung, heart, and skeletal mass in 21 species of medium to large body sized game birds. We then compared 7 of these species categorized as short flyers belonging to the order Galliforrnes with 14 other species capable of sustained flapping flight. Our comparative analyses incorporating phylogeny revealed that once accounting for body mass, Galliformes had smaller heart mass compared to other species, as shown in few previous studies. Additionally, we detected reduced tracheal diameter and lung mass in Galliforrnes, suggesting the presence of morphological pleiotropy predicted under the concept of symmorphosis. These organs all showed different levels of reciprocal correlations due to their functional connection. Residual skeletal mass was independent of flight capacity and showed no relationship with heart mass, thus indicating that selection for reduced skeletal mass may have already maximized how light a bird skeleton can be, constraining mass-independent variation in this trait. Our results suggest that cardiorespiratory organs have evolved symmorphic variation in size that reflects costs and benefits associated with different flight capacities. However, our observed differences are confounded with phylogenetic history, so additional comparative studies are needed to rigorously test this hypothesis. Received 18 June 2020. Accepted I October 2021. Key words: Anseriformes, avian anatomy, body mass, organs size, symmorphosis. El vuelo es una de las formas de movimicnto mas efectivas y cnergcticamentc mas demandantes. Sus costos energeticos cstan normalmente asociados con variacion interespccifica en eficiencia. tamaho de organos y sistemas fisiologicos que reflcjan diferentcs eapacidades dc vuelo. La variacion morfologica adaptativa podria estar limitada por las demandas tisicas que varian con el tamaho corporal; sin embargo, qucda pcndicnte el trabajo que ubique la alometria asociada con el modo de vuelo cn un eontexto ecologico y evolutive. Nuestra prediceion es que el corazon, pulmones y masas esqueleticas, asi como el diametro traqucal. debicran mostrar una correlacion reciproca positiva y hayan reducido su tamaho en especies con cscasas eapacidades de vuelo. Medimos diametro traqueal junto eon pulmon. corazon y masa esquelctica cn 21 especies dc aves dc caza mcdianas a grandes. A continuacibn comparamos 7 de estas especies categorizadas como voladoras cn cotto y pcrtcnecientes al orden GaUiformes con otras 14 especies capaces de vuelo activo sostenido. Nuestros analisis comparativos que incorporan la tilogenia rcvclan que una vcz que controlamos cl tamano corporal, las Galliforrnes tenian un corazon de menor masa comparadas con otras especies. como ban mostrado un pequeno numero de estudios prcvios. Adicionalmente. detectamos diametros traqueales reducidos y masa dc pulmones en Galliformes. Io que sugiene la presencia de una pleiotropia morfologica prevista bajo el concepto dc simorfosis. Estos organos mostraron diferentcs niveles de correlacion reeiproea debido a su conexion liincional. La masa esquelctica residual fuc independiente de la capacidad de vuelo y no mostro relacion con la masa del corazon, indicando con cllo que la seleccion para una masa esquelctica reducida podria habcr maximizado que tan ligero puedc ser el esqueleto de un ave. limitando la variacion dc masa independiente en csta caracteristica. Nuestros resultados sugieren que los organos cardiorespiratories han evolucionado una variacion simorfica que refleja los costos y beneficios asociados con diferentcs eapacidades de vuelo. Sin embargo, las diferencias observadas se eonfunden con su historia filogenetiea, por lo que se nccesitan estudios comparativos adicionalcs para sometcr rigurosamente a prueba csta hipolcsis. Palahras clave: anatomia aviar. Anseriformes. masa corporal, simorfosis. tamaho dc organos., While most birds fly, not all species practice flight with the same frequency and intensity (Rayner 1988). This difference is germane when comparing species capable of sustained active flight to [...]

Bank vole is a rodent species that shows differential susceptibility to the experimental transmission of different prion strains. In this work, the transmission features of a panel of diverse prions with distinct origins were assayed both in bank vole expressing methionine at codon 109 (Bv109M) and in transgenic mice expressing physiological levels of bank vole PrPC (the BvPrP-Tg407 mouse line). This work is the first systematic comparison of the transmission features of a collection of prion isolates, representing a panel of diverse prion strains, in a transgenic-mouse model and in its natural counterpart. The results showed very similar transmission properties in both the natural species and the transgenic-mouse model, demonstrating the key role of the PrP amino acid sequence in prion transmission susceptibility. However, differences in the PrPSc types propagated by Bv109M and BvPrP-Tg407 suggest that host factors other than PrPC modulate prion strain features. [ABSTRACT FROM AUTHOR]

Abstract One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

Abstract Background Prion diseases are characterised by a neurodegenerative pattern in which the function of immune system remains still elusive. In the present study, we evaluate if an exogenous treatment with Interleukin-12 (IL-12) and IL-18, able to activate microglia, is able to affect scrapie pathogenesis. Results Cytokines injected intracranially, induced a strong inflammatory response characterised by TNF-�� production and microglia activation. Two groups of mice were injected intracerebrally with high dose of ME7 strain of scrapie containing IL-12 and IL-18 or sterile saline. Cytokines-treated mice showed a more pronounced accumulation of PrPSc in brain tissues at 90 days post-inoculation and a shorter mean survival times than untreated mice. Conclusion We can conclude that intracerebral administration of IL-12 and IL-18 can modulate scrapie pathogenesis possibly through a microglia-mediated pattern.