in the hybrid silkworm , nd-sd/+ , the h chain derived from either the nd-sd or + allele forms disulfide linkage with the l chain derived from the + allele and these fibroins are secreted into the lumen with an equal efficiency , but the l chain derived from the nd-sd allele remains in the cell unbound to the h chain .
C1327616
secreted
C0007634
cell