Comparative analysis of growth, muscle nutrient composition, and skin transcriptome in f1 hybrids of ctenopharyngodon idella with two different body colors

summary To investigate the characteristics of growth performance, muscle quality, and color related gene expression in the F1 generation of three grass carp families with two different body colors, this study aimed to Build a golden grass carp（ ♀) Golden grass carp（ ♂) [Ctenopharyngodon idella var.gold ( ♀) ×C. idella var.gold ( ♂)] F1 generation (GG), golden grass carp（ ♀) Common body color grass carp（ ♂) [C. idella var.gold ( ♀) ×C. idella ( ♂)] F1 generation (GB) and common body color grass carp（ ♀) Common body color grass carp（ ♂) [C. idella ( ♀) ×C. idella ( ♂)] The growth characteristics, muscle quality, and skin transcriptome features of three F1 (BB) families were systematically analyzed using morphological, nutritional, and RNA seq techniques. The results showed that: (1) in terms of growth performance, the GG family had significantly higher weight gain rate and specific growth rate than the BB and GB families (P<0.05), showing a trend of GG>BB>GB; (2) In terms of muscle quality, the GG family has significantly higher water content (P<0.05) and significantly lower crude fat content (P<0.05), and the content of eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA), total amino acids (TAA), total essential amino acids (TEAA), and total flavor amino acids (TDAA) are significantly higher than those of the BB and GB families (P<0.05); (3) In terms of protein quality evaluation, the amino acid score (AAS), chemical score (CS), and essential amino acid index (EAAI) of the GG family were higher than those of the BB and GB families; (4) In terms of transcriptome analysis, differentially expressed genes (DEGs) between GG and BB, as well as between GB and BB, were significantly enriched in GO functional entries such as ATP metabolism, nucleoside monophosphate metabolism, purine nucleoside monophosphate metabolism, mitochondria, heme binding, tetrapyrrole binding, and oxidoreductase activity, as well as pathways related to oxidative phosphorylation and cell adhesion molecules. DEGs related to grass carp color formation, such as cdk4, mt-atp6, csf1r, xdh, and sox9b, were screened and obtained. The results showed that the GG family had significantly better growth performance and muscle quality than the GB and BB families, and obtained two genes related to body color differences, providing a scientific basis for elucidating the genetic molecular mechanism of body color variation and breeding of golden grass carp.