PUBLICATION

Variability in mitochondria of zebrafish photoreceptor ellipsoids

Authors
Tarboush, R., Novales Flamarique, I., Chapman, G.B., Connaughton, V.P.
ID
ZDB-PUB-140513-32
Date
2014
Source
Visual neuroscience   31: 11-23 (Journal)
Registered Authors
Connaughton, Victoria P.
Keywords
none
MeSH Terms
  • Animals
  • Larva
  • Microspectrophotometry
  • Mitochondria/chemistry
  • Mitochondria/classification
  • Mitochondria/ultrastructure*
  • Photoreceptor Cells/chemistry
  • Photoreceptor Cells/ultrastructure*
  • Zebrafish/growth & development*
PubMed
24801620 Full text @ Vis. Neurosci.
Abstract
Ultrastructural examination of photoreceptor inner segment ellipsoids in larval (4, 8, and 15 days postfertilization; dpf) and adult zebrafish identified morphologically different types of mitochondria. All photoreceptors had mitochondria of different sizes (large and small). At 4 dpf, rods had small, moderately stained electron-dense mitochondria (E-DM), and two cone types could be distinguished: (1) those with electron-lucent mitochondria (E-LM) and (2) those with mitochondria of moderate electron density. These distinctions were also apparent at later ages (8 and 15 dpf). Rods from adult fish had fewer mitochondria than their corresponding cones. The ellipsoids of some fully differentiated single and double cones contained large E-DM with few cristae; these were surrounded by small E-LM with typical internal morphology. The mitochondria within the ellipsoids of other single cones showed similar electron density. Microspectrophotometry of cone ellipsoids from adult fish indicated that the large E-DM had a small absorbance peak (∼0.03 OD units) and did not contain cytochrome-c, but crocetin, a carotenoid found in old world monkeys. Crocetin functions to prevent oxidative damage to photoreceptors, suggesting that the ellipsoid mitochondria in adult zebrafish cones protect against apoptosis and function metabolically, rather than as a light filter.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping