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Simple Summary: Silkworms are traditionally raised on mulberry leaves, but modern silk production increasingly uses artificial diets—manufactured food that replaces natural leaves. This shift helps overcome limitations like seasonal availability of mulberry leaves and allows year-round silk production. However, we do not fully understand how silkworms adapt to these artificial diets at the genetic level. Our study examined a special silkworm strain called Guican No.5, which grows well on artificial diet, to uncover the genetic changes that allow for this adaptation. By analyzing its complete genetic material, we discovered millions of genetic variations and hundreds of new genes that were not previously known in silkworms. Many of these new genes help in digesting artificial diet components and dealing with potentially harmful substances in the diet. We found that some of these genes came from wild silkworms but changed over time to handle artificial diet better, while others appear to be completely new. Also, we were able to identify new detoxification genes which shares low similarity with known proteins. These findings help us understand how insects adapt to new food sources and can guide the development of better artificial diets for silkworms, ultimately supporting more sustainable silk production methods that do not depend on mulberry cultivation. The transition from traditional mulberry leaf feeding to artificial diet cultivation represents a major advancement in modern sericulture, yet the genetic mechanisms driving this adaptation remain largely unexplored. This study investigates the genomic basis of artificial diet adaptation in the silkworm strain Guican No.5 through whole-genome resequencing and transcriptome analysis. We identified 8,935,179 single-nucleotide polymorphisms (SNPs) across all chromosomes, accounting for 2.01% of the genome, with particularly high densities observed in chromosomes 23, 26, and 28. Our analysis also revealed 879 novel transcripts, many of which are involved in digestion, detoxification, and stress response pathways. Key novel genes, including three carboxylesterases, two cytochrome P450s, one heat shock protein, and one copper/zinc superoxide dismutase, exhibited varying degrees of sequence similarity to known proteins, suggesting modifications to existing genetic frameworks. Notably, one novel P450 gene displayed only 74.07% sequence identity with its closest homolog, indicating the emergence of a new protein sequence. Additionally, several key genes showed high similarity to wild silkworm (Bombyx mandarina) proteins, underscoring their evolutionary origins. These findings provide valuable insights into the molecular mechanisms underpinning artificial diet adaptation in silkworms and offer genomic resources to enhance artificial diet formulations and breeding programs in sericulture. [ABSTRACT FROM AUTHOR] |
