Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA.
Computational Science Program, Middle Tennessee State University, Murfreesboro, TN 37132, USA.
Genes (Basel). 2022 Jul 26;13(8):1331. doi: 10.3390/genes13081331.
The visual appearance of the fish fillet is a significant determinant of consumers' purchase decisions. Depending on the rainbow trout diet, a uniform bright white or reddish/pink fillet color is desirable. Factors affecting fillet color are complex, ranging from the ability of live fish to accumulate carotenoids in the muscle to preharvest environmental conditions, early postmortem muscle metabolism, and storage conditions. Identifying genetic markers of fillet color is a desirable goal but a challenging task for the aquaculture industry. This study used weighted, single-step GWAS to explore the genetic basis of fillet color variation in rainbow trout. We identified several SNP windows explaining up to 3.5%, 2.5%, and 1.6% of the additive genetic variance for fillet redness, yellowness, and whiteness, respectively. SNPs are located within genes implicated in carotenoid metabolism (β,β-carotene 15,15'-dioxygenase, retinol dehydrogenase) and myoglobin homeostasis (ATP synthase subunit β, mitochondrial ()). These genes are involved in processes that influence muscle pigmentation and postmortem flesh coloration. Other identified genes are involved in the maintenance of muscle structural integrity (kelch protein 41b (), collagen α-1(XXVIII) chain (), and cathepsin K ()) and protection against lipid oxidation (peroxiredoxin, superoxide dismutase 2 (), sestrin-1, Ubiquitin carboxyl-terminal hydrolase-10 ()). A-to-G single-nucleotide polymorphism in β,β-carotene 15,15'-dioxygenase, and result in isoleucine-to-valine and proline-to-leucine non-synonymous amino acid substitutions, respectively. Our observation confirms that fillet color is a complex trait regulated by many genes involved in carotenoid metabolism, myoglobin homeostasis, protection against lipid oxidation, and maintenance of muscle structural integrity. The significant SNPs identified in this study could be prioritized via genomic selection in breeding programs to improve fillet color in rainbow trout.
鱼片的外观是消费者购买决策的重要决定因素。根据虹鳟鱼的饮食，均匀的亮白色或红粉色鱼片颜色是理想的。影响鱼片颜色的因素很复杂，从活鱼在肌肉中积累类胡萝卜素的能力到收获前的环境条件、早期死后肌肉代谢和储存条件不等。确定鱼片颜色的遗传标记是水产养殖行业的一个理想目标，但也是一项具有挑战性的任务。本研究使用加权单步 GWAS 来探索虹鳟鱼片颜色变化的遗传基础。我们确定了几个 SNP 窗口，分别解释了鱼片红色、黄色和白色的加性遗传方差的 3.5%、2.5%和 1.6%。SNP 位于涉及类胡萝卜素代谢（β，β-胡萝卜素 15,15'-加双氧酶、视黄醇脱氢酶）和肌红蛋白稳态（ATP 合酶亚基β、线粒体（））的基因内。这些基因参与影响肌肉色素沉着和死后肉质颜色的过程。其他鉴定的基因参与维持肌肉结构完整性（kelch 蛋白 41b (), 胶原蛋白 α-1(XXVIII) 链 (), 和组织蛋白酶 K ()) 和防止脂质氧化（过氧化物酶、超氧化物歧化酶 2 (), sestrin-1, 泛素羧基末端水解酶-10 ()）。β，β-胡萝卜素 15,15'-加双氧酶中的 A 到 G 单核苷酸多态性和导致异亮氨酸到缬氨酸和脯氨酸到亮氨酸的非同义氨基酸取代，分别。我们的观察结果证实，鱼片颜色是一种复杂的性状，由许多参与类胡萝卜素代谢、肌红蛋白稳态、防止脂质氧化和维持肌肉结构完整性的基因调节。本研究中鉴定的重要 SNP 可以通过基因组选择在虹鳟鱼的繁殖计划中优先考虑，以改善鱼片颜色。
