The promoter of Bmlp3 gene can direct fat body-specific expression in the transgenic silkworm, Bombyx mori

Abstract

The fat body plays multiple, crucial roles in the life of silkworms. Targeted expression of transgenes in the fat body of the silkworm, Bombyx mori, is important not only for clarifying the function of endogenous genes expressed in this tissue, but also for producing valuable recombinant proteins. However, fat body-specific gene expression remains difficult due to a lack of suitable tissue-specific promoters. Here we report the isolation of the fat body-specific promoter of Bmlp3, a member of the 30K protein family of silkworms. The 1.1 kb fragment from −374 to +738 of Bmlp3 displayed strong promoter activity in the cell lines BmE and Spli-221. In transgenic silkworms, a DsRed reporter gene controlled by the 1.1 kb Bmlp3 promoter fragment was expressed specifically in the fat body in a stage-specific pattern that was nearly identical to the endogenous Bmlp3 gene. We conclude that the 1.1 kb Bmlp3 promoter fragment is sufficient to direct tissue- and stage-specific expression of transgenes in the fat body of silkworms, highlighting the potential use of this promoter for both functional genomics research and biotechnology applications.Electronic supplementary materialThe online version of this article (doi:10.1007/s11248-013-9705-8) contains supplementary material, which is available to authorized users.

An efficient strategy for producing a stable, replaceable, highly efficient transgene expression system in silkworm, Bombyx mori

“…Importantly, they can also be used to improve the natural cocoon silks and produce novel silk fibers with high tensile strength, high adhesion, and other excellent properties with the silk-gland-specific expression of structurally related proteins (such as the spider dragline protein 57 58 ). Actually, other silk-gland-specific promoters (such as the FibL 59 60 , fhx 52 , and Ser1 promoters 61 ) or tissue-specific promoters (such as fat-body- 62 , midgut- 63 and hemocyte-specific promoters 64 ) can also be used to establish stable, replaceable, and highly efficient transgene expression systems in the silkworm with this generic strategy ( Figure 1 ). In addition, the FLP/ FRT and Cre/ loxP systems have been successful used for RMCE reactions in D. melanogaster 22 29 65 .…”

Transgenic characterization of two silkworm tissue‐specific promoters in the haemocyte plasmatocyte cells

“…As powerful research tools, tissue‐specific promoters are widely applied, including in bioreactors (Fraser, ), pest control (Javaid et al ., ), and gene function research. Specific promoters have been widely investigated in the fat body (Deng et al ., ), midgut (Jiang et al ., ), testis (Xu et al ., ) and silk gland (Tomita, ) in silkworms. Specific promoters were used to express exogenous or chimeric proteins in the silk gland (Hino et al ., ; Kurihara et al ., ; Tomita, ).…”

Highly efficient and inducible DNA excision in transgenic silkworms using the FLP/FRT site-specific recombination system

“…Actually, other tissue-specific promoters, such as silk gland- (Tomita et al 2003(Tomita et al , 2007Long et al 2015b), fat-body- (Deng et al 2013), midgut- (Jiang et al 2013), and testis-specific promoters (Xu et al 2015), can also be used to induce FLP gene expression in different tissues of transgenic silkworms and to achieve FLP/FRT system-based genetic mosaics in the soma and germline, as well as chromosome rearrangements, the deletion of large fragments, and other genetic engineering operations in the silkworm genome. In 2003, a binary gene expression system was developed to analyze B. mori gene function using the yeast GAL4 DNA-binding protein and its target cis-element upstream activating sequence (UAS) (Imamura et al 2003).…”