# Role Analysis of the scarb1 Gene in the Pigmentation of Neocaridina denticulata sinensis

## TL;DR

This study explores how the scarb1 gene affects body color in cherry shrimp, finding it influences pigmentation through chromatophore development.

## Contribution

The study identifies scarb1 as a key gene involved in pigmentation and provides insights for breeding strategies in ornamental shrimp.

## Key findings

- scarb1 expression is highest in red shrimp and the pre-nauplius stage.
- RNAi silencing of scarb1 increases chromatophore development in the metanauplius stage.
- A specific SNP in scarb1 shows different frequencies between yellow and other colored shrimp.

## Abstract

This study investigates the role of scavenger receptor class B type I (scarb1) in the body color of Neocaridina denticulata sinensis (cherry shrimp). This research aims to understand the relationship between scarb1 and pigmentation by analyzing the expression patterns of the scarb1 gene in different color populations and developmental stages, performing RNA interference (RNAi) to silence scarb1, and identifying single nucleotide polymorphisms (SNPs) within the gene. The results showed significant differences in scarb1 expression across color populations and developmental stages, with the highest expression in red shrimp and the pre-nauplius stage. Silencing scarb1 via RNAi increased chromatophore development in the metanauplius stage. A specific SNP in *scarb1* showed significantly different frequencies between yellow shrimp and shrimp of other colors. This study concludes that scarb1 plays a role in cherry shrimp pigmentation by influencing chromatophore development. This research provides insights into the genetic mechanisms underlying body color in cherry shrimp, which can be utilized to improve breeding strategies for desired color variations, enhancing the shrimp’s market value and benefiting the ornamental aquaculture industry.

Body color is a key economic trait for Neocaridina denticulata sinensis, an important ornamental shrimp. Scarb1 may be an important mediator of astaxanthin uptake, changing the shrimp’s body color. To discover the relationship between scarb1 and the pigmentation of cherry shrimp, the expression profiles, RNAi, and SNP genotyping of scarb1 were studied. There were significant differences in four color populations and five development stages (p < 0.05). The highest expression level of scarb1 appeared in the red population and the pre-nauplius stage. Exposure to scarb1 dsRNA increased the number and development of chromatophores at the metanauplius stage, but almost no phenotypic changes were observed at the pre-zoea stage. There was a synonymous SNP (G1593A) with a significantly different genotype frequency between the red and yellow populations (p < 0.05). The above results suggested that scarb1 is involved in pigmentation by affecting the development of chromatophores.