Naslov
Nonlinearities in plant RNA virus fitness

Autori
Lalić, Jasna

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Fakultet bioloških znanosti

Mjesto
Valencia

Datum
10.12

Godina
2012

Stranica
137

Mentor
Santiago F. Elena

Ključne riječi
Emerging viruses; RNA viruses; Tobacco etch virus; Viral fitness; Generalism vs. specialism; Genotype-by-environment (G×E) interactions; Epistasis; Adaptive fitness landscapes

Sažetak
The relationship between genotype and fitness is one of the most important functions in determining the evolutionary dynamics of a population. In this Thesis, multidimensional genotype-fitness maps have been explored. In Chapter III, the fitness of genotypes was mapped across different environments. In Chapter IV, the fitness of genotypes was mapped with respect to a particular genetic background. In Chapter V, the fitness of genotypes was mapped with respect to both environment and genetic background. The final chapter aimed to map the fitness of a partial set of genotypes to the new environment where they had evolved. In all cases, except of part II, a significant non-linear relation for viral fitness was found indicating that fitness is a unique consequence of its genotype in interaction with the genetic background and the environment. Still, it is important to note that Population Genetics does not assume linear effects being a rule in Nature ; actually, they are not. Instead ; since the response to selection depends on the fraction of variance in fitness that can be attributed to statistically linear component of mutational effects, the linear component of genotype regression for fitness is of particular importance. Hence, the adaptation depends on these additive effects. Herewith, it is worth to recall that during evolution not only genotypes change in response to an environment, but environments are also rarely constant. The heterogeneity of environments is due to both biotic and abiotic causes. In this sense, the evolutionary theory remains to be a powerful tool for inferring parasitehost interactions because we still lack much of knowledge in understanding the environmental and genetic bases of interactions, particularly in plant-virus system. It is worth keeping in mind that evolution is a process and not an event, so, evolutionary theory provides also a powerful tool for interpretation of host-parasite dynamics and alerts about the necessary design and application of disease control programmes. Biology is a science of complex systems. The constituents of a complex system interact in many different ways that lead to dynamic and emergent features that cannot be predicted satisfactorily by linear mathematical models that disregard interaction and non-additive effects. Concordantly, the essential message of the work presented here is that the dynamic interplay between viral and host populations is necessarily a non-linear one, and as such has many properties that cannot be predicted simply by analyzing the structure of their components.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA