Genetic engineering of silkworm for enhanced silk mechanical properties: a review

• Comprehensive review of genetic strategies for silkworm silk enhancement covers exogenous gene insertion, silkworm gene editing. • Discusses CRISPR-based methods and ionic control in silk microenvironment. • Highlights breakthroughs in mechanical strength and silk yield improvement. • Proposes future directions for super-fiber design via synthetic biology. The silkworm ( Bombyx mori ) is a key economic lepidoptera animal known for large-scale production of silk. Its silk, valued for outstanding mechanical properties, has been used for millennia across industries. However, inherent limitations in silk performance hinder its application in advanced fields. Genetic engineering has already been a promising strategy to enhance silk properties and expand its use. This review outlines the biological significance of silkworm silk as a natural biomaterial and highlights the need for genetic improvement. It summarizes recent advances in four strategy aspects: exogenous gene introduction, endogenous silk protein optimization, silk gland microenvironment regulation, and silk yield enhancement. It provides a comprehensive review of respective mechanism of each method, development history, and specific impacts on performance or yield. The advantages and limitations of current genetic techniques are critically evaluated. Besides, emerging trends, challenges, and future applications in textiles, medicine, and biomaterials are also discussed.