Related Experiment Video
Updated: Oct 21, 2025

Author Spotlight: Advancing Gene Silencing Research in Silkworms with dsRNA Delivery Through Feeding Chitosan Nanoparticles
Published on: October 4, 2024
Functional Characterization of Silkworm PIWI Proteins by Embryonic RNAi
Takashi Kiuchi1, Susumu Katsuma2
1Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan. kiuchi@ss.ab.a.u-tokyo.ac.jp.
Abstract:
The molecular mechanisms of sex-determination systems among insect orders and species are diverse. Therefore, genes involved in sex determination are strong candidates for insect pest management. Even though lepidopterans are major agricultural insect pests that cause widespread economic damage to various crops, their sex-determination systems have not been fully elucidated, even in the silkworm (Bombyx mori), a model lepidopteran insect. In 2014, we found that a female-specific W chromosome-derived PIWI-interacting RNA (piRNA) determines femaleness in silkworms. To analyze the function of two core silkworm piRNA biogenesis pathway genes, Siwi and BmAgo3, in the sex-determination system, we developed a genomic DNA and total RNA extraction strategy for a siRNA-injected single embryo. The siRNA-injected embryo can be molecularly sexed by W chromosome-specific DNA markers. Using complementary DNA (cDNA) reverse transcribed from the sexed RNA, we evaluated the knockdown effect of the PIWI protein-coding genes on a sexual development-related gene, Bombyx mori doublesex.
Related Concept Videos
piRNA - Piwi-interacting RNAs
RNA Interference
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
Experimental RNAi
siRNA - Small Interfering RNAs
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
MicroRNAs

