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The physical and chemical properties of wild berry fruits change dramatically during development, and the ripe berries host species-specific endophytic communities. However, the development of fungal endophytic communities during berry ripening is unknown. We studied bilberries (Vaccinium myrtillus L.), valuable natural resources in northern Europe and richest sources of phenolic compounds, to characterize dynamics of the fungal communities over fruit developmental stages (raw, veraison, and ripe). Our focus was to examine the changes in the fruit phenolic compounds associated with the fungal community structure using liquid chromatography–mass spectrometry for phenolic compounds and high-throughput sequencing technology targeting the internal transcribed spacer 2 ribosomal DNA region for endophytic fungi. We found that the fungal diversity increased with the ripening stages. The fungal profile changed dramatically through fruit development, and the veraison stage was a transition stage, where the core mycobiome of fruits changed. The fungal community structure and abundance of the most dominant genera in raw and ripe stages, Monilinia and Cladosporium , respectively, were driven by the bilberry phenolic profile. We conclude that sampling time, tissue age, and phenolic compounds play important roles in the development of fruit fungal community. Moreover, phenolic compounds could be the host's strategy to recruit beneficial microbes. [ABSTRACT FROM AUTHOR]

Longer glucan chains tend to precipitate. Glycogen, by far the largest mammalian glucan and the largest molecule in the cytosol with up to 55 000 glucoses, does not, due to a highly regularly branched spherical structure that allows it to be perfused with cytosol. Aberrant construction of glycogen leads it to precipitate, accumulate into polyglucosan bodies that resemble plant starch amylopectin and cause disease. This pathology, amylopectinosis, is caused by mutations in a series of single genes whose functions are under active study toward understanding the mechanisms of proper glycogen construction. Concurrently, we are characterizing the physicochemical particularities of glycogen and polyglucosans associated with each gene. These genes include GBE1, EPM2A and EPM2B, which respectively encode the glycogen branching enzyme, the glycogen phosphatase laforin and the laforin-interacting E3 ubiquitin ligase malin, for which an unequivocal function is not yet known. Mutations in GBE1 cause a motor neuron disease (adult polyglucosan body disease), and mutations in EPM2A or EPM2B a fatal progressive myoclonus epilepsy (Lafora disease). RBCK1 deficiency causes an amylopectinosis with fatal skeletal and cardiac myopathy (polyglucosan body myopathy 1, OMIM# 615895). RBCK1 is a component of the linear ubiquitin chain assembly complex, with unique functions including generating linear ubiquitin chains and ubiquitinating hydroxyl (versus canonical amine) residues, including of glycogen. In a mouse model we now show (i) that the amylopectinosis of RBCK1 deficiency, like in adult polyglucosan body disease and Lafora disease, affects the brain; (ii) that RBCK1 deficiency glycogen, like in adult polyglucosan body disease and Lafora disease, has overlong branches; (iii) that unlike adult polyglucosan body disease but like Lafora disease, RBCK1 deficiency glycogen is hyperphosphorylated; and finally (iv) that unlike laforin-deficient Lafora disease but like malin-deficient Lafora disease, RBCK1 deficiency's glycogen hyperphosphorylation is limited to precipitated polyglucosans. In summary, the fundamental glycogen pathology of RBCK1 deficiency recapitulates that of malin-deficient Lafora disease. Additionally, we uncover sex and genetic background effects in RBCK1 deficiency on organ- and brain-region specific amylopectinoses, and in the brain on consequent neuroinflammation and behavioural deficits. Finally, we exploit the portion of the basic glycogen pathology that is common to adult polyglucosan body disease, both forms of Lafora disease and RBCK1 deficiency, namely overlong branches, to show that a unified approach based on downregulating glycogen synthase, the enzyme that elongates glycogen branches, can rescue all four diseases. [ABSTRACT FROM AUTHOR]