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Abstract Prochlorococcus cells are the numerically dominant phototrophs in the open ocean. Cyanophages that infect them are a notable fraction of the total viral population in the euphotic zone, and, as vehicles of horizontal gene transfer, appear to drive their evolution. Here we examine the propensity of three cyanophages—a podovirus, a siphovirus, and a myovirus—to mispackage host DNA in their capsids while infecting Prochlorococcus, the first step in phage-mediated horizontal gene transfer. We find the mispackaging frequencies are distinctly different among the three phages. Myoviruses mispackage host DNA at low and seemingly fixed frequencies, while podo- and siphoviruses vary in their mispackaging frequencies by orders of magnitude depending on growth light intensity. We link this difference to the concentration of intracellular reactive oxygen species and protein synthesis rates, both parameters increasing in response to higher light intensity. Based on our findings, we propose a model of mispackaging frequency determined by the imbalance between the production of capsids and the number of phage genome copies during infection: when protein synthesis rate increase to levels that the phage cannot regulate, they lead to an accumulation of empty capsids, in turn triggering more frequent host DNA mispackaging errors.
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Mechanism of Initiation Stereocontrol in Polymerization of rac -Lactide by Aluminum Complexes Supported by Indolide–Imine Ligands
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Abstract Mating signals of insects do not only attract their intended receivers but also eavesdropping parasites and/or predators. As a result, an arms race between the host or prey and the eavesdropper ensues, propelling their co‐evolution and potentially contributing to their diversification. Here, we investigate the species interaction of the flyOrmia lineifronsthat usesNeoconocephaluskatydids as hosts for its lethal larvae. We surveyed the host use ofO. lineifronsover a 2‐year period in Kentucky and determined which species were used as hosts, the parasitism rate of each katydid host, and how many generations per year the fly displays. Four of the six surveyedNeoconocephalusspecies were parasitized and killed (Neoconocephalus triops,Neoconocephalus velox,Neoconocephalus robustus,Neoconocephalus nebrascensis) byO. lineifrons. Three of these katydid species were previously not known to be hosts ofO. lineifrons. Two of the six species were not parasitized in either year (Neoconocephalus bivocatus,Neoconocephalus retusus) even thoughO. lineifronswas active when they called. The parasitism rate of each host peaked between 38% and 100% across years. The fly had three distinct generations per year, and each generation used different katydid species as hosts. We discuss the importance of the synchronization of the three fly generations with their hosts as well as potential counteradaptations of the hosts. These semi‐independent arms races could provide valuable insights in the diversification of the hosts and their parasitoid.more » « less
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1021/acs.macromol.0c00092
