Genetics and evidence for balancing selection of a sex-linked colour polymorphism in a songbird

Colour polymorphisms play a key role in sexual selection and speciation, yet the mechanisms that generate and maintain them are not fully understood. Here, we use genomic and transcriptomic tools to identify the precise genetic architecture and evolutionary history of a sex-linked colour polymorphism in the Gouldian finch Erythrura gouldiae that is also accompanied by remarkable differences in behaviour and physiology. We find that differences in colour are associated with an ~72-kbp region of the Z chromosome in a putative regulatory region for follistatin, an antagonist of the TGF-β superfamily genes. The region is highly differentiated between morphs, unlike the rest of the genome, yet we find no evidence that an inversion is involved in maintaining the distinct haplotypes. Coalescent simulations confirm that there is elevated nucleotide diversity and an excess of intermediate frequency alleles at this locus. We conclude that this pleiotropic colour polymorphism is most probably maintained by balancing selection

Remodeling and Repair In Rhinosinusitis

Remodeling refers to the development of specific but potentially irreversible structural changes in tissue. Caucasian eosinophilic chronic rhinosinusitis (CRS) with polyps associated or not with cystic fibrosis was discriminated by edema from CRS without nasal polyps, characterized by extensive fibrotic fields. However, changes in epithelial and extracellular matrix structures are common findings in all types of chronic inflammatory diseases of upper airways, but rarely specific and highly variable in extend. Recent studies have shown that remodeling in CRS appears to occur in parallel, rather than purely subsequent to inflammation. Furthermore,some preferential remodeling associations can be recognized. Tremendous efforts have been put in research on coagulation factors,cytokines,growthfactors,and proteases supporting all phases of upper airway remodeling. The current exploration of other CRS sub-groups and of the particular link with concomitant asthma aims to optimize the classification of CRS and its staging modes and to develop novel therapies