Germ Cell Dynamics in the colonial sea squirt Perophora viridis Verrill, 1871

• Grant number: 21/10217-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2022
• End date: March 31, 2023
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Federico David Brown Almeida
• Grantee: Ruan Wendell Calheiros Cavalcante
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Pluripotent cell progenitors are associated with high regenerative capacities in animals. Its potential to differentiate into any cell type has made possible the evolution of asexual reproduction in some species. The colonial sea squirt Perophora viridis is a species that reproduces sexually and asexually through budding and due to the presence of pluripotent progenitor cells, it also has a high regenerative capacity. Previous studies have revealed the involvement of hemoblasts (a type of stem cell in the blood of sea squirts) in the processes of regeneration and budding. Despite this, both the nature and the direct involvement of these cells in asexual reproduction in sea squirts remains uncertain. Thus, the molecular characterization of these cells and their relationship with the germline of Perophora need to be studied. It is known that the development of germline progenitor cells in animals can occur through two distinct ways: one of them occurs early during embryogenesis, by maternally inherited determinants, while the other occurs through inductive signals in the embryo. Thus, the identification and characterization of germ cells is a necessary step to determine how these cells develop. The objectives of this project are: 1) to identify germ cell regions through morphology and histology in order to characterize them, 2) to use molecular markers to identify germ cells within the colony, and 3) to test whether the removal of primordial germ cells(PGCs) of the tail of the larva -the region where the PGCs are located in other species of ascidians- leads to a total removal of the germline in P. viridis; 4) Test whether in the gonadal development of blastozooids the germline stem cells (GSCs) come from gonadal precursors present in primogenitor zooids. With this project I hope to contribute to the study of the mechanisms of specification of the germline of colonial ascidians, using Perophora viridis as a model organism.