Discovering genes responsible for silk synthesis in Bombyx mori by piggyBac ‐based random insertional mutagenesis

AbstractSilkworm mutants are valuable resources for both transgenic breeding and gene discovery. PiggyBac ‐based random insertional mutagenesis has been widely used in gene functional studies. In order to discover genes involved in silk synthesis, a piggyBac‐based random insertional library was constructed usingBombyx mori, and the mutants with abnormal cocoon were particularly screened. By this means, a “thin cocoon” mutant was identified. This mutant revealed thinner cocoon shell and shorter posterior silk gland (PSG) compared with the wild type. The messenger RNA (mRNA) levels of all the three fibroin genes, includingFib ‐H,Fib ‐L andP25, were significantly down ‐regulated in the PSG of mutants. Four piggyBac insertion sites were identified inAquaporin (AQP),Longitudinals lacking protein ‐like (Lola),Glutamyl aminopeptidase ‐like (GluAP) andLoc101744460. The mRNA levels of all the four genes were significantly altered in the silk gland of mutants. In particular, the mRNA amount ofAQP, a gene responsible for the regulation of osmotic pressure, decreased dramatically immediately prior to the spinning stage in the anterior silk gland of mutants. The identification of the genes disrupted in the “thin cocoon” mutant in this study provided useful information for understanding silk production and transgenic breeding of silkworms in the future.
Source: Insect Science - Category: Biology Authors: Tags: ORIGINAL ARTICLE Source Type: research