Project description:Ulcerative colitis is a chronic inflammatory disorder for which a definitive cure is still missing. This is characterized by an overwhelming inflammatory milieu in the colonic tract where a composite set of immune and non-immune cells orchestrate its pathogenesis. Over the last years, a growing body of evidence has been pinpointing gut virome dysbiosis as underlying its progression. Nonetheless, its role during the early phases of chronic inflammation is far from being fully defined. Here we show the gut virome-associated Hepatitis B virus protein X, most likely acquired after an event of zoonotic spillover, to be associated with the early stages of ulcerative colitis and to induce colonic inflammation in mice. It acts as a transcriptional regulator in epithelial cells, provoking barrier leakage and altering mucosal immunity at the level of both innate and adaptive immunity. This study paves the way to the comprehension of the aetiopathogenesis of intestinal inflammation and encourages further investigations of the virome as a trigger also in other scenarios. Moreover, it provides a brand-new standpoint that looks at the virome as a target for tailored treatments, blocking the early phases of chronic inflammation and possibly leading to better disease management.
Project description:We performed Illumina sequencing of sRNA libraries prepared from juvenile and reproductive phase buds from the apple trees. A large number of sRNAs exemplified by 33 previously annotated miRNAs and 6 novel members displayed significant differential expression (DE) patterns in juvenile and reproductive stages. The study provides new insight into our understanding of fundamental mechanism of poorly studied phase transitions in apple and other woody plants and important resource for future in-depth research in the apple development.
Project description:Fire blight (FB) is a bacterial disease affecting plants from Rosaceae family, including apple and pear. FB develops after the infection of Erwinia amylovora, gram-negative enterobacterium, and results in burnt-like damages and wilting, which can affect all organs of the plant. Although the mechanisms underlying disease response in apples are not elucidated yet, it has been well described that FB resistance depends on the rootstock type. The main objective of this work was to identify miRNAs involved in response to bacterial infection in order to better explain apple defense mechanisms against fire blight disease. We performed deep sequencing of eighteen small RNA libraries obtained from inoculated and non-inoculated Gala apple leaves. 233 novel plant mature miRNAs were identified together with their targets and potential role in response to bacterial infection. We identify three apple miRNAs responding to inoculation (mdm-miR168a,b, mdm-miR194C and mdm-miR1392C) as well as miRNAs reacting to bacterial infection in a rootstock-specific manner (miR395 family). Our results provide insights into the mechanisms of fire blight resistance in apple.
Project description:miRNAs are key players in multiple biological processes, therefore analysis and characterization of these small regulatory RNAs is a critical step towards better understanding of animal and plant biology. In apple (Malus domestica) two hundred microRNAs are known, which most probably represents only a fraction of miRNAome diversity. As a result, more effort is required to better annotate miRNAs and their functions in this economically important species. We performed deep sequencing of twelve small RNA libraries obtained for fire blight resistant and fire blight sensitive trees. In the sequencing results we identified 116 novel microRNAs and confirmed a majority of previously reported apple miRNAs. We then experimentally verified selected candidates with RT-PCR and stem-loop qPCR and performed differential expression analysis. Finally, we identified and characterized putative targets of all known apple miRNAs. In this study we considerably expand the apple miRNAome by identifying and characterizing dozens of novel microRNAs. Moreover, our data suggests that apple microRNAs might be considered as regulators and markers of fire blight resistance.
Project description:Our data showed that lipid and glucose metabolic pathways genes were expressed at higher levels in gluteofemoral adipocyte fraction in pears, while genes associated with inflammation were higher in both abdominal and gluteofemoral apple adipocyte fraction. Gluteofemoral adipocyte chromatin from pear-shaped women contained a significantly higher number of differentially open ATAC-seq peaks relative to chromatin from the apple-shaped gluteofemoral adipocytes. In contrast, abdominal adipocyte chromatin openness showed few differences between apple and pear-shaped women. We revealed a correlation between gene transcription and open chromatin at the proximity of the TSS of some of the differentially expressed genes.
Project description:Winter dormancy is an adaptative mechanism that temperate and boreal trees have developed to protect their meristems against low temperatures. In apple trees (Malus domestica), cold temperatures induce bud dormancy at the end of summer/beginning of the fall. Apple buds stay dormant during winter until they are exposed to a period of cold, after which they can resume growth (budbreak) and initiate flowering in response to warm temperatures in spring. It is well-known that small RNAs modulate temperature responses in many plant species, but however, how small RNAs are involved in genetic networks of temperature-mediated dormancy control in fruit tree species remains unclear. Here, we have made use of a recently developed ARGONAUTE (AGO)-purification technique to isolate small RNAs from apple buds. A small RNA-seq experiment resulted in the identification of small RNAs that change their pattern of expression in apple buds during dormancy.
Project description:Apple leaf spot caused by the Alternaria alternata f. sp. mali (ALT1) fungus is one of the most devastating diseases of apple (Malus × domestica). We identified a hairpin RNA (hpRNA)-mediated small RNAs, MdhpRNA277, from apple (cv. ‘Golden Delicious’) that is induced by infection with ALT1. MdhpRNA277 produces mdm-siR277-1 and mdm-siR277-2, which target five R genes, MdRNL1, MdRNL2, MdRNL3, MdRNL4, and MdRNL5, that are expressed at high levels in the resistant apple variety ‘Hanfu’ and at low levels in the susceptible variety ‘Golden Delicious’ following ALT1 infection. MdhpRNA277 is strongly induced in ‘Golden Delicious’ but was not induced in ‘Hanfu’ following ALT1 inoculation. The promoter activity of MdhpRNA277 was much stronger in ‘Golden Delicious’ than in ‘Hanfu’ after ALT1 inoculation. We identified a single nucleotide polymorphism (SNP) in the MdhpRNA277 promoter region between the susceptible variety ‘Golden Delicious’ (pMdhpRNA277-GD) and resistant variety ‘Hanfu’ (pMdhpRNA277-HF). The transcription factor MdWHy binds to pMdhpRNA277-GD, but not to pMdhpRNA277-HF. Transgenic ‘GL-3’ apple lines expressing pMdhpRNA277-GD: MdhpRNA277 were more susceptible to ALT1 infection than were those expressing pMdhpRNA277-HF:MdhpRNA277 due to induced mdm-siR277 accumulation and low levels of expression of the five target R genes. The failure of MdWHy to bind to pMdhpRNA277-HF might contribute to the low levels of MdhpRNA277 and mdm-siR277-1/-2 expression and the high levels of R gene expression and resistance to Alternaria leaf spot in resistant apple varieties. We confirmed that the SNP in pMdhpRNA277 is associated with Alternaria leaf spot resistance by analyzing the progeny of three additional crosses. The SNP identified in this study could be used as a marker to distinguish between apple varieties that are resistant or susceptible to Alternaria leaf spot.