Hurd, P. | Search bioRxiv

bioRxiv2021

Amplicon sequencing of variable 16S rRNA and ITS2 regions reveal honeybee susceptibility to diseases resulted of their dietary preferences under anthropogenic landforms

European Apis mellifera and Asian Apis cerana honeybees, are essential crop pollinators. Microbiome studies can provide complex information on health and fitness of these insects in relation to environmental changes, and plant availability. Amplicon sequencing of variable regions of 16S rRNA and internally transcribed spacers (ITSs) allow identification of the metabiome. These methods provide a tool for monitoring otherwise uncultured microbes isolated from the gut of the honeybees. They also help monitor the composition of the gut fungi and, intriguingly, pollens collected by the insect. Here, we present data from amplicon sequencing of the 16S rRNA and ITS2 regions from honeybees collected at various time points from anthropogenic landforms as urban areas in Poland, UK, Spain, Greece, and Thailand. We have analysed microbial composition of honeybee intestine as well as fungi and pollens. We conclude that differences between samples were mainly influenced by the bacteria, plant pollens and fungi, respectively. Moreover, honeybees feeding on a honeydew diet, mainly based on sugars, were more prone to fungal pathogens (Nosema ceranae) and neogregarines. Finally, the period when honeybees switch to the winter generation (longer-lived forager honeybees) is the most sensitive to diet perturbations and hence pathogens attack, for the whole beekeeping season. It is possible that evolutionary adaptation of bees fails to benefit them in the modern anthropomorphised environment.

zoology↗

bioRxiv2020

Systemic mutational rescue in Escherichia coli elicited by a valency dependent, high affinity protein DNA interaction

The controlled formation of sequence specific DNA protein complexes is a fundamental feature of most genetic transactions. Studies of the impact of point mutations on the function of individual components, such as repressors, remains a key aspect of many Systems and Synthetic Biology research programmes. One of the most dramatic systemic consequences of a point mutation is exhibited by the monomeric DNA methyltransferases M.HhaI and M.EcoRII, where substitution of a single, catalytic cysteine by either glycine or alanine, creates a lethal gain of function phenotype. In vivo expression of these point mutants promotes the deposition of high affinity nucleoprotein complexes that arrest replication in vivo, causing cell death. Interestingly, it appears that a systemic response to expression of these mutant enzymes is dramatically enhanced when they are expressed as synthetic dimers. A previously unreported form of "mutational rescue" appears to be triggered as a result of networked crosslinking of host cell DNA resulting from an increased valency of nucleoprotein complex formation. This finding may have significance for developing molecular interventions for the controlled regulation of genome function and for the development of novel antimicrobial and anticancer strategies.

genomics↗