, a like gene identified from , involved in metamorphosis and baculovirus infection.

BACKGROUND

As a member of the immunoglobulin superfamily, hemolins play a vital role in insect development and defense against pathogens. However, the innate immune response of to baculovirus infection varies among different insects.

METHODS AND RESULTS

In this study, the like gene from a Crambidae insect, , was cloned, and its role in insect development and baculovirus infection was analyzed. A 1,528 bp contig as potential -like gene of was reassembled from the transcriptome. Further, the complete sequence of () was cloned and sequenced. The cDNA of was 1,515 bp in length and encoded 408 amino acids. The deduced amino acid of CmHem has relatively low identities (41.9-62.3%) to various insect hemolins. However, it contains four Ig domains similarity to other insect hemolins. The expression level of was the highest in eggs, followed by pupae and adults, and maintained a low expression level at larval stage. The synthesized siRNAs were injected into mature larvae, and the transcription decreased by 51.7%. Moreover, the abdominal somites of larvae became straightened, could not pupate normally, and then died. Infection with a baculovirus, granulovirus (CnmeGV), the expression levels of in the midgut and fat body of significantly increased at 12 and 24 h, respectively, and then soon returned to normal levels.

CONCLUSIONS

Our results suggested that hemolin may be related to the metamorphosis of . Exposure to baculovirus induced the phased expression of gene in the midgut and fat body of , indicated that involved in the immune recognition of Crambidae insects to baculovirus.