Coloniality and gene expression of stem cell markers during budding of the ascidian Perophora viridis Verril, 1871

• Grant number: 23/13244-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2024
• End date: May 31, 2026
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Federico David Brown Almeida
• Grantee: Ivan Andre Morillo Guerrero
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Within tunicates, coloniality has evolved several times independently with colonial species in two of the group's three classes. Bud shapes and budding mechanisms are different among colonial lineages. Colonial organisms are composed of semi-dependent modules, which correspond to clonal individuals of asexual reproduction (zooids). The different types of budding mechanisms facilitated the evolution of coloniality, however, the tissues, or cells, that give rise to the modular development of each individual in the colony, also known as zooids, remain not well defined. Zooids are always in continuous renewal through a process called budding. The budding process in some species exhibits developmental mechanisms regulated by 'coordinated and synchronous' cycles, unlike other species in which development occurs 'independently and asynchronously'. In the first chapter of this study, we propose to explore how budding times and lifespans of colonial ascidian zooids can vary intra- and inter-specifically. What developmental processes are guided by the colony's modules? What processes result from the interaction between colony modules? What processes are governed at the colonial level? Comparing the development times and longevity of zooids between ascidian species will allow us to determine the degree of modular dependence in budding and identify regulatory processes acting at different levels of colonial organization.In budding, complete new bodies, including all somatic and germline tissues, develop from the remains of adult tissues. The colonial ascidian Perophora viridis can reproduce asexually by stolonial budding. Through histological studies of budding, the role of stem cells presents in the blood of several species of ascidians (hemoblasts) and of the stolon septum cells has been studied. However, characterization using molecular markers and proliferation analysis of these cells has not yet been performed. Therefore, we propose to determine the location and dynamics of stem cells in the budding process in P. viridis.