Fig. 1

Cas9/sgRNA mediated gene editing of fib-H of the silkworm. a Schematic diagram of the sgRNA-targeting sites. The two boxes indicate the two exons of Bmfib-H, and the black line indicates the gene locus. The sgRNA targeting sites S is located on the sense strand of exon-2. F′ and R’ were used to anneal the upstream and downstream regions of the targeting site. The sgRNA targeting sequence is in black, and the protospacer adjacent motif (PAM) sequence is in red. b The different phenotypes of Cas9/sgRNA induced mutations. The left is the normal cocoon, the middle side is the thin-layered cocoon and the right is the naked pupae. c Various types of insertion mutations screened from homozygous mutant silkworms (G3). H1, 19 bp insertion; H2, 13 bp insertion, and H3, 20 bp insertion. Deletions are indicated by hyphens and insertions are shown in green lowercase letters. The PAM sequence is in red. d Comparison of predicted amino acid sequences of H3 and wild type amino acid sequence. The missing amino acids are replaced with dashes. The numbers on the right indicate the amino acid residue positions of the proteins. Premature stop codons are shown in blue letters and black point. e Silk glands of the wild type (WT) and the mutant from the 2nd day to 4th day of 5th larvae stage. All the scale bars represent 1 cm