Publication: Estudios de evolución rápida en microorganismos bajo condiciones selectivas y de cambio global: algunos modelos y aplicaciones en biología
Loading...
Files
Official URL
Full text at PDC
Publication Date
2017-12-05
Authors
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad Complutense de Madrid
Citations
Exportar
Abstract
Los microorganismos son organismos modelo para el estudio de la evolución. Entender los procesos que operan modificando los microorganismos en el tiempo y como estos han transformado los organismos hasta la actualidad, pueden permitirnos abordar la problemática actual de pérdida de diversidad o ayudarnos a entender la complejidad de los organismos contemporáneos. Dentro de los trabajos enmarcados en esta tesis, hemos capitalizado la versatilidad de la evolución experimental como marco de investigación para abordar diferentes cuestiones adaptativas y evolutivas en microrganismos. Frente al desafío que representa la problemática del Cambio Global, hemos realizado diferentes experimentos de adaptación frente a estresantes antropogénicos (incremento de la temperatura, osmio, berilio y charcas minería de uranio) en el fitoplancton, a lo que se ha sumado un trabajo de revisión del estado actual del conocimiento. Las especies dentro del fitoplancton presentan una capacidad de adaptación diferencial, sin relación directa con el grupo taxonómico o el nicho ecológico. Los resultados obtenidos frente a presiones selectivas intensas, que implica una reducción drástica de la población, indican que la adaptación puede tener lugar gracias a mutantes presentes por azar dentro de las poblaciones naturales. Por tanto, en relación a los efectos del Cambio Global, la diversidad fitoplanctónica puede verse reducida, alterando la biogeografía futura de las poblaciones y favoreciendo a las especies con mayor plasticidad. Por otro lado, investigamos una transición evolutiva, como es el origen de la multicelularidad, bajo diferentes condiciones ecológicas. Por medio de una selección por sedimentación en S. cerevisiae, obtuvimos el fenotipo multicelular snowflake yeast a partir de su ancestro unicelular. La restricción nutricional no resultó limitante a la hora de obtener por selección fenotipo snowflake, ni implica una reversión hacia la unicelularidad a partir de un fenotipo snowflake. Sin embargo, la complejidad de las interacciones entre los organismos y su ambiente, pueden facilitar la persistencia de subpoblaciones (el fenotipo unicelular), así como la expansión de metapoblaciones (persistencia de poblaciones mixtas)...
Globally, microorganisms play a key role in the maintenance of biogeochemical cycles and the status of ecosystems, particularly in aquatic environments where they act as primary producers. Microorganisms serve as model organisms for the study of evolution, they present an inherent importance due to its ecological role, ubiquity, its adaptive antecedents and preponderance throughout evolution. Understanding the processes that operate by modifying microorganisms over time and how they have modify living organisms until today, would enable as to tackle the current rate of loss of biological diversity or help us understand the complexity of contemporary organisms. Evolutionary processes can be address via experimental evolution, by means of controlled field or laboratory experiments. Evolution experiments make use of different organisms, often microorganisms, to examine evolutionary hypothesis, study adaptive processes and approach populations dynamics. Taking advantage of this methodology we can approach the issue of global change or to address evolutionary questions. Anthropogenic activities have reshaped and modified the ecosystems and the biosphere globally, becoming the current driving evolutionary force. In particular, is of primarily importance to study the effect of anthropogenic stressors in aquatic ecosystems. Phytoplankton is the base of the aquatic ecosystems, responsible of a significant amount of the atmospheric oxygen and plays an essential part in the “biological pump”, regenerating the atmospheric composition. Temperature increase and acidification, both in marine and freshwater environments, is a direct threaten to the aquatic ecosystems and indirectly to all the living forms on earth. Also the release of stressors, especially heavy metals, in aquatic environments result in a direct hazard to living forms, entailing a serious risk for the environments and human health. Phytoplankton is the base of the aquatic ecosystems, responsible of a significant amount of the atmospheric oxygen and plays an essential part in the “biological pump”, regenerating the atmospheric composition. Approaching this nowadays problem form the phytoplankton perspective is useful to address the problematic of anthropogenic...
Globally, microorganisms play a key role in the maintenance of biogeochemical cycles and the status of ecosystems, particularly in aquatic environments where they act as primary producers. Microorganisms serve as model organisms for the study of evolution, they present an inherent importance due to its ecological role, ubiquity, its adaptive antecedents and preponderance throughout evolution. Understanding the processes that operate by modifying microorganisms over time and how they have modify living organisms until today, would enable as to tackle the current rate of loss of biological diversity or help us understand the complexity of contemporary organisms. Evolutionary processes can be address via experimental evolution, by means of controlled field or laboratory experiments. Evolution experiments make use of different organisms, often microorganisms, to examine evolutionary hypothesis, study adaptive processes and approach populations dynamics. Taking advantage of this methodology we can approach the issue of global change or to address evolutionary questions. Anthropogenic activities have reshaped and modified the ecosystems and the biosphere globally, becoming the current driving evolutionary force. In particular, is of primarily importance to study the effect of anthropogenic stressors in aquatic ecosystems. Phytoplankton is the base of the aquatic ecosystems, responsible of a significant amount of the atmospheric oxygen and plays an essential part in the “biological pump”, regenerating the atmospheric composition. Temperature increase and acidification, both in marine and freshwater environments, is a direct threaten to the aquatic ecosystems and indirectly to all the living forms on earth. Also the release of stressors, especially heavy metals, in aquatic environments result in a direct hazard to living forms, entailing a serious risk for the environments and human health. Phytoplankton is the base of the aquatic ecosystems, responsible of a significant amount of the atmospheric oxygen and plays an essential part in the “biological pump”, regenerating the atmospheric composition. Approaching this nowadays problem form the phytoplankton perspective is useful to address the problematic of anthropogenic...
Description
Tesis inédita de la Universidad Complutense de Madrid, Facultad de Veterinaria, Departamento de Producción Animal, leída el 05-06-2017.