-Hologenome : microbiota (0453.4115)
The hologenome concept: role of microbiota in the fitness and evolution of humans, animals and plants
Suggested graduate course to be given by Prof. Eugene Rosenberg
Course title: The hologenome concept: role of microbiota in the fitness and evolution of humans, animals and plants
" -Hologenome : microbiota "
Time: One lecture hour per week, fall semester
Course outline:
We are in the midst of a paradigm change in biology. Ground-breaking research over the last 15 years has given rise to the hologenome concept. This concept posits that the holobiont (host plus all of its associated microorganisms) and its hologenome (sum of the genetic information of the host and its symbiotic microorganisms), acting in concert, function as a unique biological entity and therefore as a level of selection in evolution.
All animals and plants harbour abundant and diverse microbiota, including viruses. Often the amount of symbiotic microorganisms and their combined genetic information far exceed that of their host. The microbiota with its microbiome, together with the host genome, can be transmitted from one generation to the next and thus propagate the unique properties of the holobiont. The microbial symbionts and the host interact in a cooperative way that affects the health of the holobiont within its environment. Beneficial microbiota protects against pathogens, provides essential nutrients, catabolizes complex polysaccharides, renders harmful chemicals inert, and contributes to the performance of the immune system. In humans and animals, the microbiota also plays a role in behavior. The sum of these cooperative interactions characterizes the holobiont as a unique biological entity. Genetic variation in the hologenome can be brought about by changes in either the host genome or the microbial population genomes (microbiome). Evolution by cooperation can occur by amplifying existing microbes, gaining novel microbiota and by acquiring microbial and viral genes by HGT. Under environmental stress, the microbiome can change more rapidly and in response to more processes than the host organism alone and thus influences the evolution of the holobiont. Prebiotics, probiotics, synbiotics and phage therapy are applied aspects of the hologenome concept.
The theoretical and experimental studies that will be discussed in the proposed course should be of interest to graduate students in all Departments of the Faculty of Life Science because of its interdisciplinary nature. The following is a tentative list of lecture subjects:
1. Introduction: Symbioses and the Hologenome Concept
The hologenome concept
Concepts and definitions
2. Origin of Prokaryotes and Eukaryotes
Speculation on the origin of protocells
Origin of prokaryotes and eukaryotes
Origin of viruses
Origin of multicellar organisms
3. Abundance and Diversity of Microbiota
Microbiota of invertebrates
Microbiota of vertebrates
Microbiota of plants
Factors that affect abundance and diversity of microbiota
4. Microbiotas are Transmitted between Holobiont Generations
Transmission of microbiota and social behavior of holobionts
5. Microbiotas are Part of Holobiont Fitness
Microbiotas protect against pathogens
Microbiotas provide nutrients to their hosts
Microbiotas influence animal and plant development
Microbiotas influence holobiont behavior
Bacteria play a role in mating preference
Microbiotas detoxify toxic substances
Temperature adaptation
6. Variation in Holobionts
Darwinism and Lamarckism
Modes of variation within holobionts
Microbial amplification
Acquisition of novel symbionts
Horizontal gene transfer
Acquisition of novel symbionts and the hygiene hypothesis
7. Viruses are part of the Holobiont`s Fitness and Evolution
Abundance and diversity of viruses in holobionts
Transmission of viruses
Viruses are part of the fitness and evolution of