The Evolution of Diversity

Since the beginning of time, the pre-biological and the biological world have seen a steady increase in complexity of form and function based on a process of combination and re-combination. The current modern synthesis of evolution known as the neo-Darwinian theory emphasises population genetics and does not explain satisfactorily all other occurrences of evolutionary novelty. The authors suggest that symbiosis and hybridisation and the more obscure processes such as polyploidy, chimerism and lateral transfer are mostly overlooked and not featured sufficiently within evolutionary theory. They suggest, therefore, a revision of the existing theory including its language, to accommodate the scientific findings of recent decades

Reticulate Evolution: Symbiogenesis, Lateral Gene Transfer, Hybridization and Infectious heredity

info:eu-repo/semantics/publishedVersio

From conifers to cognition: microbes, brain, and behavior

We would like to thank Hans Kuepper (Munich), Juergen Haas (Edinburgh), and Rob Moir† (Harvard) for constructive comments on the MS. This work was funded in part by the Benter Foundation.Peer reviewedPublisher PD

A Comparative Genomics Exploration of Inter-partner Metabolic Signaling in the Coral-algal Symbiosis

At the foundation of coral reef ecosystems is the symbiosis between the coral host and its microbial community, particularly its photoautotrophic algae from the family Symbiodiniaceae. As a symbiosis centered around nutritional exchange, determining the mechanisms involved in the maintenance of this cooperative exchange is central to understanding how it breaks down. As the nutritional transfer primarily consists of sugars, this work first focuses on the cnidarian insulin signaling pathway, an evolutionarily important metazoan pathway involved in diverse functions, most notably metabolism. This dissertation unveiled 360 putative cnidarian insulin-like peptides (cnILPs) from existing transcriptomic datasets, where they were previously missed due to the bioinformatic methods employed. Significantly, symbiotic corals and anemones possessed the greatest diversity in insulin-like peptides compared to other cnidarian taxa. Conserved transcriptional responses of the cnILPs were also detected, particularly cnILP-B down-regulation in response to symbiosis along with a non-specific cnILP up-regulation in response to thermal stress. These trends coincide well with known transcriptional responses of ILPs in diverse organisms ranging from the nematode C. elegans to humans, implicating for the first time that insulin signaling similarly functions in symbiosis and stress response in non-bilaterians. This dissertation also focused on the genome of the thermotolerant Durusdinium trenchii, which is well-known to confer thermotolerance on diverse coral species. We identified considerable duplication of gene blocks, more than 10-100x that of other Symbiodinaceae species, in support of previous hypotheses regarding a near or whole genome duplication event. Importantly, within these duplicated gene regions we detected extensive positive selection on genes central to the maintenance and repair of chloroplast structures like thylakoid membranes and photosystem II, a primary site of damage during photoinhibition. Widespread genome duplication and adaptive selection on photosynthetic functions is significant as it aligns with previous physiological studies identifying this as a factor in the thermotolerance of D. trenchii. This dissertation for the first time not only substantiates previous hypotheses of genome duplication in D. trenchii, but connects this duplication to the acquisition of thermotolerance in D. trenchii. Altogether, this dissertation highlights the importance for further investigations into the functions of the insulin signaling pathway in coral-algal symbioses and stress response, as well as confirms genomic duplication and selection as contributing to the evolutionary acquisition of thermotolerance in the symbiont D. trenchii

Cnidofest 2018: the future is bright for cnidarian research.

The 2018 Cnidarian Model Systems Meeting (Cnidofest) was held September 6-9th at the University of Florida Whitney Laboratory for Marine Bioscience in St. Augustine, FL. Cnidofest 2018, which built upon the momentum of Hydroidfest 2016, brought together research communities working on a broad spectrum of cnidarian organisms from North America and around the world. Meeting talks covered diverse aspects of cnidarian biology, with sessions focused on genomics, development, neurobiology, immunology, symbiosis, ecology, and evolution. In addition to interesting biology, Cnidofest also emphasized the advancement of modern research techniques. Invited technology speakers showcased the power of microfluidics and single-cell transcriptomics and demonstrated their application in cnidarian models. In this report, we provide an overview of the exciting research that was presented at the meeting and discuss opportunities for future research

Perspectives for Virulence Management: Relating Theory to Experiment

This paper reviews our current knowledge about the evolution of virulence in pathogen-host systems, with an emphasis on the interface between the theoretical and experimental literature. After giving a methodically oriented overview of the field, stressing restrictions and caveats, the paper attempts to summarize the main results on virulence evolution gleaned from the literature. From that perspective the authors identify what they see as gaps in our current knowledge that need to be filled to transform the study of virulence evolution and management into a mature science

Meiosis

Meiosis is the key process underlying sexual reproduction in eukaryotes, occurring in single-celled eukaryotes and in most multicellular eukaryotes including animals and most plants. Thus meiosis is of considerable interest, both at the scientific level and at the level of natural human curiosity about sexual reproduction. Improved understanding of important aspects of meiosis has emerged in recent years and major questions are starting to be answered, such as: How does meiosis occur at the molecular level, How did meiosis and sex arise during evolution, What is the major adaptive function of meiosis and sex. In addition, changing perspectives on meiosis and sex have led to the question: How should meiosis be taught. This book proposes answers to these questions, with extensive supporting references to the current literature

Inactivation of pathogens on food and contact surfaces using ozone as a biocidal agent

This study focuses on the inactivation of a range of food borne pathogens using ozone as a biocidal agent. Experiments were carried out using Campylobacter jejuni, E. coli and Salmonella enteritidis in which population size effects and different treatment temperatures were investigate