Identification and characterization of Spätzle in Myzus persicae and its role during microbial infection

Area of Science:

• Insect immunology
• Molecular biology
• Genetics

Background:

• Spätzle (Spz) is a Toll receptor ligand vital for insect innate immunity.
• The immune function of Spz in the aphid Myzus persicae is not well understood.

Purpose of the Study:

• To identify and characterize Spz genes in Myzus persicae.
• To investigate the role of Spz in the innate immune response of M. persicae against microbial infections.

Main Methods:

• Identification and cloning of 7 Spz genes from M. persicae.
• Phylogenetic analysis of MpSpzs.
• Gene expression analysis in different tissues and developmental stages.
• RNA interference (RNAi) for gene silencing.
• Assessment of mortality rates after microbial challenge.
• Measurement of lysozyme expression.

Main Results:

• Seven Spz genes (MpSpzs) were identified in M. persicae, each containing a Spz domain.
• Phylogenetic analysis showed MpSpzs clustering with Spz genes from other insect species.
• MpSpzs were primarily expressed in 1st-instar nymphs, hemolymph, and embryos.
• Expression of MpSpzs showed a positive response to infections by Escherichia coli, Staphylococcus aureus, and Beauveria bassiana.
• Gene silencing of MpSpzs significantly increased M. persicae mortality following microbial infection.
• Suppression of MpSpz led to a significant reduction in lysozyme expression.

Conclusions:

• Spätzle plays a significant role in the innate immune response of Myzus persicae against microbial pathogens.
• MpSpz is involved in regulating immune gene expression, such as lysozyme.
• This study provides new insights into the function of Spätzle in aphid immunity.