Pathological and physiological functional cross-talks ofα-synuclein and tau in the central nervous system

α-Synuclein and tau are abundant multifunctional brain proteins that are mainly expressed in the presynaptic and axonal compartments of neurons,respectively.Previous works have revealed that intracellular deposition ofα-synuclein and/or tau causes many neurodegenerative disorders,including Alzheimer’s disease and Parkinson’s disease.Despite intense investigation,the normal physiological functions and roles ofα-synuclein and tau are still unclear,owing to the fact that mice with knockout of either of these proteins do not present apparent phenotypes.Interestingly,the co-occurrence ofα-synuclein and tau aggregates was found in post-mortem brains with synucleinopathies and tauopathies,some of which share similarities in clinical manifestations.Furthermore,the direct interaction ofα-synuclein with tau is considered to promote the fibrillization of each of the proteins in vitro and in vivo.On the other hand,our recent findings have revealed thatα-synuclein and tau are cooperatively involved in brain development in a stage-dependent manner.These findings indicate strong cross-talk between the two proteins in physiology and pathology.In this review,we provide a summary of the recent findings on the functional roles ofα-synuclein and tau in the physiological conditions and pathogenesis of neurodegenerative diseases.A deep understanding of the interplay betweenα-synuclein and tau in physiological and pathological conditions might provide novel targets for clinical diagnosis and therapeutic strategies to treat neurodegenerative diseases.

Sharing roosts but not ectoparasites:high host-specificity in bat flies and wing mites of Miniopterus schreibersii and Rhinolophus ferrumequinum(Mammalia:Chiroptera)

Schreiber’s bent-winged bat Miniopterus schreibersii and the greater horseshoe bat Rhinolophus ferrumequinum are widespread and common cavernicolous species across southern Europe that host numerous specialized ectoparasite species.The objective of this study was to characterize the species assemblage,genetic diversity,and host specificity of bat flies(Nycteribiidae,Diptera)and wing mites(Spinturnicidae,Acari)found on these bat hosts in Serbia and Bosnia and Herzegovina.Notably,while bat flies lay puparia on the cave walls and can thus be transmitted indirectly,wing mites require direct body contact for transmission.Morphological identification and sequencing of a 710-bp fragment of cytochrome oxidase I gene of 207 bat flies yielded 4 species,3 on M.schreibersii and 1 on R.ferrumequinum.Sequencing of a 460-bp small subunit ribosomal RNA fragment,in all 190 collected wing mites revealed 2 species,1 per host.In no case was a parasite associated with 1 host found on the other host.Species and genetic diversity of flies were higher in M.schreibersii,likely reflecting their host’s larger colony sizes and migratory potential.Mite species of both hosts showed similarly low diversity,likely due to their faster life history and lower winter survival.Our findings highlight a remarkably high host-specificity and segregation of ectoparasite species despite direct contact among their hosts in the roost,suggesting a defined host preference in the investigated ectoparasite species.Furthermore,the differences in ectoparasite genetic diversity exemplify the interplay between host and parasite life histories in shaping parasite population genetic structure.