To demonstrate that parthenogenetic silkworms and the silkworms used to induce them are genetically identical, we conducted molecular genetic and cytological analyses of chromosome composition in the parthenogenetic moths. Ovarian eggs were extracted from mother moths and exposed to hot water to induce parthenogenetic development. Molecular genetic analysis confirmed that the autosomes of mother moths and the resulting parthenogenetic moths shared the same genotype. Histological analysis and trait observation in the subsequent generation of parthenogenetic silkworms revealed that the parthenogenetic moths were diploid with a ZW sex chromosome type. Therefore, parthenogenetic moths induced by hot water were clonal copies of the mother moth. These findings indicate that parthenogenetic silkworms induced by hot water treatment are clonal individuals derived from the mother moth.

 Silk is a promising material for sustainable biotechnology due to its excellent mechanical properties and biodegradability. In this study, we developed novel silk fibers functionalized with cohesin domains, enabling the specific binding of dockerin-fused enzymes. This approach draws inspiration from the cellulosome, a natural protein complex in cellulolytic anaerobic bacteria that organizes multiple catalytic enzymes on a central scaffold. Within the cellulosome, each enzyme carries a dockerin domain that binds with high specificity and affinity to its corresponding cohesin domain on the scaffoldin protein. To mimic this modular assembly system, we designed an artificial scaffoldin protein composed of multiple cohesin domains and genetically introduced it into silkworms. The resulting silk, referred to as scaffoldin silk, displays cohesin domains on its filaments, allowing specific organization of dockerin-fused enzymes via cohesin–dockerin interactions. We evaluated the binding performance of two types of scaffoldin silk, using dockerin-fused cellulases derived from genetically modified termite enzymes. First, scaffoldin was fused to a silk-binding peptide and co-expressed in the posterior silk glands. Second, cohesin domains were genetically fused to fibroin, generating fibroin-fused scaffoldin silk. This version allows degumming at 60°C, enabling effective sericin removal and reducing nonspecific protein adsorption, thereby enhancing the specificity of dockerin-fused enzyme binding. Fibroin-fused scaffoldin silk presents a sustainable solution for scalable bioreactor systems. These findings open new avenues for industrial applications of silk by enabling post-production functionalization with catalytic enzymes, allowing flexible and interchangeable enzyme attachment.

 Lipid droplets (LDs) within the cytoplasm are organelles essential for physiological functions through lipid metabolism in eukaryotes. In mammals, the dynamics and functions of LDs have been subjected to molecular-level analyses because of their relevance to diseases such as hyperlipidemia. In contrast, although the function of LDs is established, the understanding of the dynamics of LDs in insects based on experimental evidence is especially limited. Long-chain fatty acids that accumulate in LDs through glyceride formation serve as pheromone precursors during pheromonogenesis. However, the formation mechanism of LDs during this process has not been experimentally confirmed. Here, fluorescence microscopy showed that LDs in pheromone gland (PG) cells of decapitated silkmoths, Bombyx mori were associated with the endoplasmic reticulum (ER). We also observed the fusion and growth of LDs. However, LD fusion was observed only few times over at least 24 h, suggesting that fusion is not the primary mechanism of LD growth. Therefore, LDs in PG cells originate from the ER and exhibit dynamics similar to those observed in other eukaryotes, including mammals. This suggests that the mechanisms involved in the accumulation and consumption of glycerides and genes related to LD formation are conserved. The results of this study contribute to a further comprehensive understanding of the genes expressed in PG cells of moths, in comparison with the gene sets of other eukaryotes.