dc.contributor.advisor | Corrochano Peláez, Luis María | es |
dc.contributor.advisor | Cánovas López, David | es |
dc.creator | Cea Sánchez, Sara | es |
dc.date.accessioned | 2023-06-06T11:11:21Z | |
dc.date.available | 2023-06-06T11:11:21Z | |
dc.date.issued | 2023-04-21 | |
dc.identifier.citation | Cea Sánchez, S. (2023). Transcriptional regulation by the Velvet complex during development in Neurospora crassa. (Tesis Doctoral Inédita). Universidad de Sevilla, Sevilla. | |
dc.identifier.uri | https://hdl.handle.net/11441/146948 | |
dc.description.abstract | Developmental transitions in fungi are key to their success in colonizing new
habitats and adapting to stressful environmental conditions. Developmental transitions
are regulated by environmental factors such as light. Neurospora crassa is an ascomycete
heterothallic filamentous fungus and a model organism for research on several aspects of
fungal biology, including the study of light sensing and morphogenesis during
development. The life cycle of N. crassa includes asexual development with the
formation of vegetative conidia that are easily dispersed, and sexual development, a
complex process involving the formation of sexual reproductive structures (perithecia),
were the ascospores (meiotic products) are formed.
The velvet complex is a fungal-specific protein complex that participates in the
regulation of gene expression in response to environmental signals such as light, as well
as developmental processes, pathogenesis, and secondary metabolism. In this thesis, we
have characterized the role of the velvet complex (the velvet proteins VE-1 and VE-2,
and the methyltransferase LAE-1) during different stages of the life cycle of N. crassa.
We first started studying the role of this complex during asexual development. Mutations
in ve-1 or ve-2, but not in lae-1 led to shorter height of aerial tissue and an increased
development of macroconidia. Additionally, when ve-1 or ve-2 mutations were combined
with mutations in the transcription factor gene fl, which is an activator of
macroconidiation, lead to increased microconidiation. VE-2 and LAE-1 were detected
during vegetative growth and conidiation, unlike VE-1 which was mostly observed in
samples obtained from submerged vegetative hyphae. We propose that VE-1 is the
limiting component of the velvet complex during conidiation and has a major role in the
transcriptional regulation of conidiation. Characterization of the role of VE-1 by RNA
seq experiments during mycelial growth and asexual development (conidiation) allowed
the identification of a set of genes regulated by VE-1, most notably the transcription factor
genes vib-1 and fl, that participate in the regulation of conidiation. We propose that VE-
1 and VE-2 regulate the development of aerial tissue and the balance between macro- and
microconidiation in coordination with FL and VIB-1. During sexual development, strains lacking VE-1 and/ or VE-2 display a markedly
delayed and reduced sexual development with fewer fruiting bodies compared to the wildtype
strain. Alterations in the development of female structures, protoperithecia, in the
ve-1 and ve-2 mutants suggested that the VE-1/VE-2 complex should regulate
transcription during sexual development. We have characterized the transcriptome of
wild-type and Dve-1 mutant strains over the time course of sexual development in both
dark and light. Among the misregulated genes, we detected genes that are essential for
sexual development, such as mitogen-activated protein kinase (MAPK) signaling
pathways, cell-cell fusion genes (ham genes) and transcription factor genes.
Electrophoretic mobility shift essays of the promoter regions of the four MAPK genes
suggest that VE-1 could be regulating sexual development by binding directly to
promoters of these key regulatory genes. Furthermore, we detected transcription of ve-1,
ve-2, and lae-1 during all stages of sexual development, but the three proteins were not
detected in the later stages of development (4 and 6 days after fertilization), suggesting a
major role for the velvet complex in the early stages of sexual development.
Our results provide key insights into the control of multistage development
processes by the regulatory velvet complex in the fungus N. crassa, and will help to
understand how environmental signals are integrated in the fungal cell to regulate
development. | es |
dc.format | application/pdf | es |
dc.format.extent | 195 p. | es |
dc.language.iso | eng | es |
dc.rights | Attribution-NonCommercial-NoDerivatives 4.0 Internacional | * |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | * |
dc.title | Transcriptional regulation by the Velvet complex during development in Neurospora crassa | es |
dc.type | info:eu-repo/semantics/doctoralThesis | es |
dcterms.identifier | https://ror.org/03yxnpp24 | |
dc.type.version | info:eu-repo/semantics/publishedVersion | es |
dc.rights.accessRights | info:eu-repo/semantics/openAccess | es |
dc.contributor.affiliation | Universidad de Sevilla. Departamento de Genética | es |
dc.date.embargoEndDate | 2024-04-21 | |