Oxidative stress, photodamage and the role of screening pigments in insect eyes

Teresita C. Insausti, Marion Le Gall, Claudio R. Lazzari

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Using red-eyed mutant triatomine bugs (Hemiptera: Reduvidae), we tested the hypothesis of an alternative function of insect screening pigments against oxidative stress. To test our hypothesis, we studied the morphological and physiological changes associated with the mutation. We found that wild-type eyes possess a great amount of brown and red screening pigment inside the primary and secondary pigment cells as well as in the retinular cells. Red-eyed mutants, however, have only scarce red granules inside the pigmentary cells. We then compared the visual sensitivity of red-eyed mutants and wild types by measuring the photonegative responses of insects reared in light:dark cycles [12?h:12?h light:dark (LD)] or constant darkness (DD). Finally, we analyzed both the impact of oxidative stress associated with blood ingestion and photodamage of UV light on the eye retina. We found that red-eyed mutants reared in DD conditions were the most sensitive to the light intensities tested. Retinae of LDreared mutants were gradually damaged over the life cycle, while for DD-reared insects retinae were conserved intact. No retinal damage was observed in non-fed mutants exposed to UV light for 2?weeks, whereas insects fed on blood prior to UV exposure showed clear signs of retinal damage. Wild-type insects exposed to UV light showed a marked increase in the amount and density of screening pigments.

Original languageEnglish (US)
Pages (from-to)3200-3207
Number of pages8
JournalJournal of Experimental Biology
Volume216
Issue number17
DOIs
StatePublished - Sep 2013

Keywords

  • Compound eyes
  • Hematophagy
  • Mutants
  • Ocelli
  • Ommochromes

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Physiology
  • Aquatic Science
  • Animal Science and Zoology
  • Molecular Biology
  • Insect Science

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