Effects of Dietary β-Carotene on the Gonadal Color, Pigmentation, and Regulation Mechanisms in Sea Urchin Strongylocentrotus Intermedius
This study aims to clarify the dose–response relationship between dietary β-carotene levels and gonadal pigment deposition and regulation mechanisms related to the carotenoid synthesis of <i>Strongylocentrotus intermedius</i> based on a 60-day feeding trial and subsequent transcriptome a...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-06-01
|
| Series: | Fishes |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2410-3888/10/7/304 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | This study aims to clarify the dose–response relationship between dietary β-carotene levels and gonadal pigment deposition and regulation mechanisms related to the carotenoid synthesis of <i>Strongylocentrotus intermedius</i> based on a 60-day feeding trial and subsequent transcriptome analysis. Adult sea urchins (initial weight: 9.33 ± 0.21 g) of three cages were given one of the dry feeds with different doses of β-carotene (0 mg/kg, 150 mg/kg, 300 mg/kg) or fresh kelp (<i>Saccharina japonica</i>). The results indicated that the weight gain rate (WGR) of sea urchins increased with the addition of β-carotene, with that of the C300 group being markedly higher than that of the C0 group. The addition of β-carotene significantly improved the redness (a*) and yellowness (b*) values of the gonads, with sea urchins in the C300 group exhibiting closest gonad coloration to those in the kelp-fed group. Meanwhile, β-carotene and echinenone in the gonads of the C300 group showed the highest contents, reaching 1.96 μg/kg and 11.97 μg/kg, respectively. Several differential genes, enriched in the pathways of steroid biosynthesis, oxidative phosphorylation, and ubiquitination, were screened based on transcriptome analysis. Real-time PCR further demonstrated that β-carotene significantly upregulated the expression of <i>cholesterol 25-hydroxylase</i> (<i>CH25H</i>), <i>NADH dehydrogenase subunit 1</i> (<i>ND1</i>), <i>NADH dehydrogenase subunit 2</i> (<i>ND2</i>), and <i>NADH dehydrogenase subunit 4</i> (<i>ND4</i>) while it downregulated the expression of <i>24-dehydrocholesterol reductase</i> (<i>DHCR24</i>). These results showed that 300 mg/kg β-carotene significantly increased the WGR, redness, and yellowness values, as well as the contents of β-carotene and echinenone in the gonads of <i>S. intermedius</i>. On the one hand, dietary β-carotene increased NADH enzyme activity, which participates in echinenone synthesis by donating electrons for the transformation of β-carotene to echinenone synthesis. On the other hand, the addition of β-carotene inhibited cholesterol synthesis by increasing the expression of <i>CH25H</i> and decreasing the expression of <i>DHCR24</i>, which could in turn increase the fluidity and permeability of the cell membranes and the transport efficiency of β-carotene and echinenone from the digestive tract to the gonads. These results provided fundamental insights into the production of sea urchin gonads with market-favored colors. |
|---|---|
| ISSN: | 2410-3888 |