Experiments on competitive exclusion

• Grant number: 15/02689-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2015
• End date: December 31, 2015
• Field of knowledge: Biological Sciences - Zoology
• Principal Investigator: Daniel José Galafasse Lahr
• Grantee: Giulia Magri Ribeiro
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 13/04585-3 - Deciphering the major trends of molecular and morphological evolution in the Amoebozoa, AP.JP

Abstract

For typical growth curves bacterial model has been used. Overall, It has four phases: lag, log, stationary and decline. Protists are an useful system to study population dynamics, where there are still many ecological questions that can be made. In this project, we plan to investigate the competitive exclusion principle in these organisms. To this end, we develop an efficient method to measure growth curves in Arcella and based on this method we will measure competitive exclusion. We established clonal cultures of some protists preferably strains of lineage of arcellinida, because they leave the test when they die which allows quantification of death rate. We will make daily samples for each of the lines for counting. We will follow the methodology described by Glase consisting of 5 replicates of each experimental group, removing five samples from each 50 ¼L per day of measurement. We calculate the mean and standard deviation of the samples, with this information we will model there growth curve, using the equations of logistic model as a base. Using the equations of Lotka-Volterra competition as the base model to develop the equations of our system. For the construction of the growth curves and simulations, we use the program R. With these experiments we expect to find if arcellinida present typical growth curves: with lag phase, exponential, stationary and decline. And from this, if there is competitive exclusion.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LAHR, DANIEL J. G.; KOSAKYAN, ANUSH; LAR, ENRIQUE; MITCHELL, EDWARD A. D.; MORAIS, LUANA; PORFIRIO-SOUSA, ALFREDO L.; RIBEIRO, GIULIA M.; TICE, ALEXANDER K.; PANEK, TOMAS; KANG, SEUNGHO; et al. Phylogenomics and Morphological Reconstruction of Arcellinida Testate Amoebae Highlight Diversity of Microbial Eukaryotes in the Neoproterozoic. Current Biology, v. 29, n. 6, p. 991+, MAR 18 2019. (13/25729-3, 15/02689-1, 13/04585-3, 13/12852-1)

RIBEIRO, GIULIA MAGRI; PRADO, PAULO INACIO; COUTINHO, RENATO MENDES; RILLO, MARINA COSTA; PEREIRA JUNIOR, SAMUEL; PORFIRIO-SOUSA, ALFREDO L.; LAHR, DANIEL J. G.. Growth Rate Modulation Enables Coexistence in a Competitive Exclusion Scenario Between Microbial Eukaryotes. ACTA PROTOZOOLOGICA, v. 58, n. 4, p. 17-pg., 2019-01-01. (15/02689-1, 13/19250-7, 14/23497-0, 13/25729-3)