Comparative transcriptomics reveals candidate carotenoid color genes in an East African cichlid fish

Show full item record



Pashay Ahi , E , A. Lecaudey , L , Ziegelbecker , A , Steiner , O , A. Glabonjat , R , Goessler , W , Lass , A & Sefc , K M 2020 , ' Comparative transcriptomics reveals candidate carotenoid color genes in an East African cichlid fish ' , BMC Genomics , vol. 21 , 54 .

Title: Comparative transcriptomics reveals candidate carotenoid color genes in an East African cichlid fish
Author: Pashay Ahi, Ehsan; A. Lecaudey, Laurène; Ziegelbecker, Angelika; Steiner, Oliver; A. Glabonjat, Ronald; Goessler, Walter; Lass, Achim; Sefc, Kristina M.
Contributor organization: Organismal and Evolutionary Biology Research Programme
Date: 2020-01-16
Language: eng
Number of pages: 15
Belongs to series: BMC Genomics
ISSN: 1471-2164
Abstract: Background Carotenoids contribute significantly to animal body coloration, including the spectacular color pattern diversity among fishes. Fish, as other animals, derive carotenoids from their diet. Following uptake, transport and metabolic conversion, carotenoids allocated to body coloration are deposited in the chromatophore cells of the integument. The genes involved in these processes are largely unknown. Using RNA-Sequencing, we tested for differential gene expression between carotenoid-colored and white skin regions of a cichlid fish, Tropheus duboisi "Maswa", to identify genes associated with carotenoid-based integumentary coloration. To control for positional gene expression differences that were independent of the presence/absence of carotenoid coloration, we conducted the same analyses in a closely related population, in which both body regions are white. Results A larger number of genes (n = 50) showed higher expression in the yellow compared to the white skin tissue than vice versa (n = 9). Of particular interest was the elevated expression level of bco2a in the white skin samples, as the enzyme encoded by this gene catalyzes the cleavage of carotenoids into colorless derivatives. The set of genes with higher expression levels in the yellow region included genes involved in xanthophore formation (e.g., pax7 and sox10), intracellular pigment mobilization (e.g., tubb, vim, kif5b), as well as uptake (e.g., scarb1) and storage (e.g., plin6) of carotenoids, and metabolic conversion of lipids and retinoids (e.g., dgat2, pnpla2, akr1b1, dhrs). Triglyceride concentrations were similar in the yellow and white skin regions. Extracts of integumentary carotenoids contained zeaxanthin, lutein and beta-cryptoxanthin as well as unidentified carotenoid structures. Conclusion Our results suggest a role of carotenoid cleavage by Bco2 in fish integumentary coloration, analogous to previous findings in birds. The elevated expression of genes in carotenoid-rich skin regions with functions in retinol and lipid metabolism supports hypotheses concerning analogies and shared mechanisms between these metabolic pathways. Overlaps in the sets of differentially expressed genes (including dgat2, bscl2, faxdc2 and retsatl) between the present study and previous, comparable studies in other fish species provide useful hints to potential carotenoid color candidate genes.
Subject: BCO2
Body coloration
Color genes
Gene expression
1184 Genetics, developmental biology, physiology
Peer reviewed: Yes
Rights: cc_by
Usage restriction: openAccess
Self-archived version: publishedVersion

Files in this item

Total number of downloads: Loading...

Files Size Format View
s12864_020_6473_8_1.pdf 1.488Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record