Molecular Characterization of a Lysozyme Gene and Its Altered Expression Profile in Crowded Beet Webworm (Loxostege sticticalis).
Hailong Kong, Min Lv, Nian Mao, Cheng Wang, Yunxia Cheng, Lei Zhang, Xingfu Jiang, Lizhi Luo
Author Information
Hailong Kong: College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, 225009, China.
Min Lv: Institute of Agricultural Sciences of Lixiahe District in Jiangsu Province, Yangzijiang Road, NO. 568, Yangzhou, 225007, China.
Nian Mao: College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, 225009, China.
Cheng Wang: College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, 225009, China.
Yunxia Cheng: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, NO. 2, Beijing, 100193, China.
Lei Zhang: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, NO. 2, Beijing, 100193, China.
Xingfu Jiang: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, NO. 2, Beijing, 100193, China.
Lizhi Luo: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, NO. 2, Beijing, 100193, China.
There is growing evidence that insects living in high-density populations exhibit an increase in immune function to counter a higher risk of disease. This phenomenon, known as density-dependent prophylaxis, has been experimentally tested in a number of insect species. Although density-dependent prophylaxis is especially prevalent in insects exhibiting density-dependent phase polyphenism, the molecular mechanism remains unclear. Our previous study demonstrated that the antibacterial activity of lysozyme is important for this process in the beet webworm Loxostege sticticalis. In this study, a lysozyme cDNA from L. sticticalis was cloned and characterized. The full-length cDNA is 1078 bp long and contains an open reading frame of 426 bp that encodes 142 amino acids. The deduced protein possesses structural characteristics of a typical c-type lysozyme and clusters with c-type lysozymes from other Lepidoptera. LsLysozyme was found to be expressed throughout all developmental stages, showing the highest level in pupae. LsLysozyme was also highly expressed in the midgut and fat body. Elevated LsLysozyme expression was observed in L. sticticalis larvae infected by Beauveria bassiana and in larvae reared under crowding conditions. In addition, the expression level of LsLysozyme in infected larvae reared at a density of 10 larvae per jar was significantly higher compared to those reared at a density of l or 30 larvae per jar. These results suggest that larval crowding affects the gene expression profile of this lysozyme. This study provides additional insight into the expression of an immune-associated lysozyme gene and helps us to better understand the immune response of L. sticticalis under crowding conditions.
References
Proc Natl Acad Sci U S A. 2001 Oct 23;98(22):12590-5
[PMID: 11606746]
