A class B scavenger receptor mediates the cellular uptake of carotenoids in Drosophila

Area of Science:

• Biochemistry
• Genetics
• Cell Biology

Background:

• Carotenoids are vital for preventing chronic disease and vitamin A deficiency.
• Invertebrate models, like Drosophila, are used to study carotenoid metabolism due to non-lethal vitamin A deficiency.
• The enzyme converting carotenoids to vitamin A has been identified in Drosophila.

Purpose of the Study:

• To identify the molecular basis of blindness in the Drosophila ninaD mutant.
• To investigate the role of the ninaD gene in carotenoid uptake and metabolism.
• To understand the function of class B scavenger receptors in carotenoid distribution.

Main Methods:

• Genetic analysis of the ninaD mutant in Drosophila.
• Molecular identification of the ninaD gene and its encoded protein.
• Phenotypic analysis of carotenoid levels and visual function in ninaD mutants.

Main Results:

• The ninaD mutation causes a defect in cellular carotenoid uptake.
• The ninaD gene encodes a class B scavenger receptor essential for visual chromophore formation.
• Loss of ninaD function leads to a carotenoid-free, vitamin A-deficient phenotype.

Conclusions:

• Class B scavenger receptors are crucial for the cellular uptake of dietary carotenoids.
• ninaD plays a vital role in making carotenoids available for metabolism and physiological functions.
• This study provides insight into carotenoid distribution and utilization in animals.