Functional analysis of hemolin gene from silkworm, Bombyx mori - immune and de- velopment

Hemolin, an immunoglobulin-like protein, is involved in the immunity and development of Lepidoptera, but its exact functions are still unclear. In this work, the quantitative PCR and Western blot analysis were used to study the effects of exogenous substances on hemolin transcription and translation in the silkworm midgut. Also, RNA interference was used to examine the effects of hemolin on wing disc development of silkworm. we found that the transcription and expression of hemolin gene could be up-regulated effectively after injection of inactive Escherichia coli and cell wall components (LPS and PGN) into silkworm midgut. However, no any changes in transcription and expression of hemolin were observed by the injection of BmNPV (Bombyx mori nuclear polyhydrosis virus). The protein-protein interaction between hemolin and yippee was verified by Co-immunoprecipitation (Co-IP) in silkworm wing discs. In addition, the silence of hemolin gene by RNA interference could lead to adult wing hypoplasia in most hatched moths. Our study provides some useful information regarding the functions of hemolin associated with the immune and developmental mechanisms in silkworm.