RT Dissertation/Thesis
T1 Mechanisms of gill regeneration in the mayfly Cloeon dipterum
A1 Martín Blanco, Carlos Antonio
K1 Genetica
K1 Biologia celular
K1 Genetica animal
K1 Informatica
AB Regeneration, the process by which an organism is capable of developing damaged or lost structures of its body anew, something that has fascinated humanity for millennia. Why are some organisms capable of regeneration while others are not?The work developed in this thesis deals with the first detailed description of the regeneration process in the gills of nymphs of Cloeon dipterum, a species of the order Ephemeroptera, which includes insects commonly known as mayflies.The introduction addresses the topic of regeneration and defines classical concepts, such as epimorphosis and morphallaxis, along with more current ones, such as blastema formation or the concept of intercalary regeneration, regeneration through stem cells, or dedifferentiated cells. Examples of organisms with different regenerative capacities and the main signaling mechanisms described as required during the regeneration process, which are conserved in metazoans, are also introduced. In a second part of the introduction, C. dipterum is presented as an emerging model for regeneration research. In particular, the nymph of C. dipterum will be described as an ideal model of regeneration, focusing especially on the evolutionary novelty and functions of its gills, which are a critical organ of its respiratory and sensory systems.The work is divided into four parts that make up the four sections of the Results section. First, the process of growth of normal and regenerating gills is quantitatively and comparatively described, with a special focus on the possible systemic effects of regeneration. Additionally, the proliferation of the gills is described in detail, establishing a basis for the second part of this thesis. In the second part, two regeneration stages are studied at the transcriptomic level, compared with contralateral unamputated gills and, in turn, with control gills from unoperated individuals. In the third part of the results, selected candidate genes from the previous Cloeon study in the model organism Drosophila melanogaster are studied by attenuating the expression of these genes during the regeneration process of the wing imaginal disc after apoptosis induction. The last section of results deals with the possible systemic effects that regeneration could produce in unamputated gills.In the discussion of this thesis, we will go through the main differences in the regeneration of Cloeon gills compared to other insect species. Why does the regeneration of gills not affect the growth of unoperated gills or the growth dynamics of the operated individual? After this, we will discuss hypotheses about how the acceleration of growth in regenerating gills would occur and critically analyze the possible weaknesses of the first two parts of this study.The discussion of the transcriptomic analysis is full of hypotheses mainly based on the assumption of the conservation of the function of Cloeon genes and the orthologs we assigned in Drosophila melanogaster. Since functional annotation is mainly based on automatic orthology assignment methods by sequence homology, these assignments must be considered an approximation. Nevertheless, I add, as an opinion note, that the majority of the genes appearing in this study and those that have been left out have an overall "biological sense". After this clarification, the analysis of differentially expressed genes reveals a possible state of "gene repression" in the regeneration stages studied, in which a group of overexpressed genes appears to be maintained during regeneration and includes both genes already known to be necessary for regeneration, as well as others not previously associated with this process, at least in insects.The third part of the discussion focuses on the genes studied in the functional analysis in D. melanogaster. Various possible mechanisms of action of the proteins encoding these genes are reviewed, as well as their described functions and their possible role in regeneration, as well as their conservation in the mechanism.Finally, the discussion revolves around the genes studied that are repressed in regeneration stages and reveal possible functions of "normal" gills. These functions are consistent with those previously described for this organ, such as gas exchange, ion exchange, and sensory functions, and we add genes/proteins to these processes. However, genes are revealed that suggest a possible function not previously described. The analysis of these genes leads us to propose gills as endocrine organs, and we hypothesize possible functions that are yet to be demonstrated and discovered.
YR 2024
FD 2024
LK https://hdl.handle.net/10433/23361
UL https://hdl.handle.net/10433/23361
LA es
NO Programa de Doctorado en Biotecnología, Ingeniería y Tecnología QuímicaLínea de Investigación: Biología del DesarrolloClave Programa: DBICódigo Línea: 107
NO Universidad Pablo de Olavide. Departamento de Fisiología, Anatomía y Biología Celular
DS RIO
RD May 9, 2026