Function Study Of SVWC Protein From Musca Domestica In The Antibacterial Reaction

Musca domestica?Md?,belongs to Insecta,Diptera and Musca,has short life history and show strong reproductive capacity.Md show good adaptability to environment,so it is considered as a model organism to study insect physiology and biochemistry.Based on previous study of digital expression profiles of Md after bacterial challenge experiments,the high level expression of SVWC?Single domain von Willebrand factor type C?family genes was observed.In this study,we embarked on a systematic bioinformatics analysis of SVWC gene in Md;We cloned and identified a gene sequence?XM₀05175861.3?containing SVWC domain,and the gene was named as MdSVWC1.Meanwhile,the function of the MdSVWC1 in the Md was analyzed.The study provided useful evidence for exploreing the role of SVWC protein family in the Md immune system.Subsequently,28 MdSVWC genes were screened by biological information method.The ORFs of the MdSVWC gene members are short,and most of them have signal peptides.The MdSVWC family has similar gene duplications in the Md genome.In the evolution process of MdSVWC,some genes contain the insertion or deletion of exons.In addition,both the distribution and length of exons&introns in SVWC gene family are different.The sequence of MdSVWC protein family was analyzed and the results showed that MdSVWC was a class of small molecule secretory proteins with 8 cysteine.Results of phylogenetic analysis showed that the MdSVWC could be divided into 8 groups according to their protein sequence and motif composition.Experiments of Real-time quantitative PCR were employed to detect the expression patterns of MdSVWC1 in different developmental stages and tissues..The highest expression level of MdSVWC1 was observed in the eggs stage.The expression level of MdSVWC1 in the fat body was the highest value in different tissues.After House flies are stimulated by bacteria,the expression of MdSVWC1 was up-regulated at 3 h in Md larvae after challenge by Escherichia coli?E.coli?and Staphylococcus aureus?S.aureus?,and the result of protein level detection was in accordance with the data of mRNA level.With Western blot,MdSVWC1 could combine with Gram negative bacteria?E.coli?and Gram positive bacteria?B.subtilis,B.megurus?,under the effect of 100 mM Ca²⁺,MdSVWC1 could promote the accumulation of bacteria in vitro.