IBBEA   24401
INSTITUTO DE BIODIVERSIDAD Y BIOLOGIA EXPERIMENTAL Y APLICADA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The first steps towards multicellularity
Autor/es:
CRISTIAN A. SOLARI
Lugar:
Frederiction
Reunión:
Conferencia; II International Volvox Conference; 2013
Institución organizadora:
University of New Brunswick
Resumen:
What were the size-related advantages that caused single cells to start living in groups? Primordial groups of undifferentiated cells might have benefited from decreased predation, as well as having novel opportunities to increase nutrient uptake, nutrient storage, and possibly enhance motility capabilities, to name a few of the dominant hypotheses. We have tested these hypotheses in Gonium pectorale, a colonial volvocine green algae that ranges from 1 to 16 cells. We have analyzed previous data of the Volvocales on motility and growth rates, and performed experiments at different nutrient concentrations and temperatures to compare growth rates between G. pectorale and the unicellular volvocine algae Chlamydomonas reinhardtii. Using the phagotrophic euglenoid Peranema trichophorum, we have also measured predation rates on C. reinhardtii and G. pectorale populations composed of colonies of different sizes. Our analysis supports the hypothesis that predation pressure was an important selective pressure for the origin of multicellularity. We think that the extra-cellular matrix necessary for cell clustering might have been co-opted for storage and used as a nutrient source when needed. Our evidence backed by theoretical analysis shows that increased motility and nutrient uptake were probably not selective advantages for the first cell groups.