Transgenesis approaches for functional analysis of peptidergic cells in the silkworm Bombyx mori

Abstract

The domestic silkworm, Bombyx mori represents an insect model of great scientific and economic importance. Besides the establishment of a stable germline transformation using the PiggyBac vector, technically feasible methods for in vivo gene delivery and transient gene expression were developed using viral based vectors, especially Sindbis viruses and baculoviruses. The recombinant baculovirus, Autographa californica multiple nucleopolyhedrovirus (AcMNPV), commonly used for large-scale protein production in permissive cell lines or insects, has been used for foreign gene transfer into specific peptidergic cells of B. mori in vivo. Since targeted gene expression is essential for functional analysis of neuropeptide genes and their receptors, the baculovirus-mediated gene transfer can serve as a reliable approach in reverse genetic studies in the silkworm. We review various strategies employing the baculovirus vector system for transient expression of molecular markers and transcription factors in specific peptidergic cells to investigate their roles in B. mori. We also use this system for functional analysis of neuropeptide signaling in the ecdysis behavioral sequence. Our data indicate that the AcMNPV vector is suitable for efficient delivery of foreign genes and their expression directed into specific peptidergic neurons and endocrine cells of B. mori larvae and pupae. However, some modifications of the vector and steps for optimization are necessary to minimize negative effects of viral infection on the host development. The transient gene expression using the AcMNPV and other virus vectors are promising tools for analysis of molecular mechanisms underlying various neuroendocrine processes during development of B. mori.

Natalisin, a tachykinin-like signaling system, regulates sexual activity and fecundity in insects

“…Drosophila melanogaster has been the best model system, allowing functional studies of neuropeptides and their receptors by the use of highly advanced molecular genetic tools and various publicly available resources (6). A number of other insect species, especially those with sequenced genomes, such as Bombyx mori and Tribolium castaneum, also have been used for investigations into the functions of neuropeptide signals, using piggyBac transformation (7) and RNAi (8,9).…”

Autophagy and its physiological relevance in arthropods: Current knowledge and perspectives

“…In particular, techniques for efficient gene transfer (stable germline transformation through transposon-based vectors or transient expression of genes by using virus vectors) or gene silencing (RNAi) have been developed for this species in the last ten years. 49,50 Thus, silkworm can be an excellent nondrosophilid model system for tackling a broad range of questions concerning autophagy.…”

Multiple neuropeptides produced by sex-specific neurons control activity of the male accessory glands and gonoducts in the silkworm Bombyx mori

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