Transcriptional activation of c3 and hsp70 as part of the immune response of Acropora millepora to bacterial challenges

PLoS One. 2013 Jul 4;8(7):e67246. doi: 10.1371/journal.pone.0067246. Print 2013.

Abstract

The impact of disease outbreaks on coral physiology represents an increasing concern for the fitness and resilience of reef ecosystems. Predicting the tolerance of corals to disease relies on an understanding of the coral immune response to pathogenic interactions. This study explored the transcriptional response of two putative immune genes (c3 and c-type lectin) and one stress response gene (hsp70) in the reef building coral, Acropora millepora challenged for 48 hours with bacterial strains, Vibrio coralliilyticus and Alteromonas sp. at concentrations of 10(6) cells ml(-1). Coral fragments challenged with V. coralliilyticus appeared healthy while fragments challenged with Alteromonas sp. showed signs of tissue lesions after 48 hr. Coral-associated bacterial community profiles assessed using denaturing gradient gel electrophoresis changed after challenge by both bacterial strains with the Alteromonas sp. treatment demonstrating the greatest community shift. Transcriptional profiles of c3 and hsp70 increased at 24 hours and correlated with disease signs in the Alteromonas sp. treatment. The expression of hsp70 also showed a significant increase in V. coralliilyticus inoculated corals at 24 h suggesting that even in the absence of disease signs, the microbial inoculum activated a stress response in the coral. C-type lectin did not show a response to any of the bacterial treatments. Increase in gene expression of c3 and hsp70 in corals showing signs of disease indicates their potential involvement in immune and stress response to microbial challenges.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alteromonas / physiology
  • Animals
  • Anthozoa / genetics*
  • Anthozoa / immunology
  • Anthozoa / microbiology
  • Colony Count, Microbial
  • Complement C3 / genetics*
  • Complement C3 / immunology
  • Coral Reefs
  • HSP70 Heat-Shock Proteins / genetics*
  • HSP70 Heat-Shock Proteins / immunology
  • Host-Pathogen Interactions / immunology*
  • Lectins, C-Type / genetics
  • Lectins, C-Type / immunology
  • Microbial Consortia / physiology
  • Transcriptional Activation / immunology*
  • Vibrio / physiology

Substances

  • Complement C3
  • HSP70 Heat-Shock Proteins
  • Lectins, C-Type

Grant support

This research was funded by NSF-OCE grant (0851123) awarded to MRL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.