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Characterization of calbindin-positive cones in primates.
C Chiquet1, O Dkhissi-Benyahya, N Chounlamountri
1INSERM U371, Cerveau et Vision, Unité 371, 18 avenue du Doyen Lépine, 69675 Cedex, Bron, France.
Neuroscience
|November 28, 2002
Summary
Calbindin is found in the cones of most primates, varying in distribution among species and opsin types. Its presence in diurnal species suggests a role potentially linked to visual adaptations.
Area of Science:
- Ophthalmology
- Neuroscience
- Evolutionary Biology
Background:
- Calbindin is a calcium-binding protein found in various tissues, including the nervous system.
- Photoreceptors, specifically cones, are responsible for color vision and function differently based on opsin content and light adaptation.
- Understanding the distribution of calbindin in primate cones can provide insights into visual system evolution and function.
Purpose of the Study:
- To characterize calbindin-positive photoreceptors and their opsin content in diverse primate species.
- To investigate the presence and distribution of calbindin in cones of nocturnal prosimians, New World monkeys, Old World monkeys, and humans.
- To correlate calbindin localization with opsin types and diurnal/nocturnal adaptations.
Main Methods:
- Utilized combined multiple labeling techniques with fluorescent probes and antibodies.
- Targeted antibodies against calbindin, short-wavelength opsin, and mid-long wavelength opsin.
- Employed peanut agglutinin lectin cytochemistry and confocal microscopy for detailed analysis.
Main Results:
- Calbindin is present in cones of all studied primates except Microcebus (nocturnal prosimian).
- Calbindin is absent in rods across all primate species examined.
- Observed distinct patterns of calbindin and opsin co-localization in human, macaque, and marmoset cones, with variations in short-wavelength cones.
Conclusions:
- Calbindin distribution in primate cones varies significantly, particularly between humans and other primates, and correlates with opsin type.
- The absence of calbindin in nocturnal Microcebus cones and its presence in diurnal species suggest a role in light adaptation.
- Further research is needed to elucidate the precise function of calbindin in photoreceptor properties and visual adaptations.
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