Banca de DEFESA: AMANDA BARRETO CAMPOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : AMANDA BARRETO CAMPOS
DATA : 28/02/2020
HORA: 14:00
LOCAL: Salão Nobre, Instituto de Biologia, Universidade Federal da Bahia
TÍTULO:

Viral Infections and Coral Bleaching

PALAVRAS-CHAVES:

Coral reefs, Viral Bleaching, Viral Infections, Viral Lysogenic Cycle

PÁGINAS: 45
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia Teórica
RESUMO:

Coral bleaching consists in the population decrease of zooxanthellae cells within coral tissue and is associated with coral starvation, being considered one of the main causes of coral mortality. There are two well-understood coral bleaching pathways, Oxidative Stress Bleaching and Bacterial Infection Bleaching; however, several evidences indicate a correlation between coral bleaching and viral infections. Several studies indicate a probable latent viral infection in zooxanthellae cells, where viral particles are expressed from algal cell exposure to stressors related to bleaching, such as intense UV radiation and high temperatures, leading to cell lysis. Although there is evidence of a possible role of giant virus infections in coral bleaching, there are still no mechanistic explanations for linking viral infections to coral health status. Here, we built a mathematical model to investigate the putative behavior of zooxanthellae population dynamics under the influence of the infectious dynamics of giant viruses, where viruses are able to establish a latent infection in the host. From an extensive study of the parameter values related to the infection process and reproductive strategy of giant viruses, we found that high rates of lysogenic infection and vertical transfer of viral infection are related to healthy coral status, whilst shifts from lysogenic to lytic reproduction are liked to a bleached state. In addition, we suggest that annual fluctuation of environmental factors may lead to the appearance of bleaching cycles. We suggest that this unique dynamics should play an important and previously neglected role in coral bleaching events. Here we propose a new hypothesis for coral bleaching - Viral Coral Bleaching - pointing out the theoretical conditions under which this bleaching pathway should be relevant.

MEMBROS DA BANCA:
Presidente - 2356247 - PEDRO MILET MEIRELLES
Externo ao Programa - 287213 - SUANI TAVARES RUBIM DE PINHO
Externo à Instituição - GUILHERME ORTIGARA LONGO