Baculoviral p94 homologs encoded in Cotesia plutellae bracovirus suppress both immunity and development of the diamondback moth, Plutellae xylostella  

作　　者：Yonggyun Kim Rahul Hepat 

机构地区：[1]Department of Bioresource Sciences, Andong National University, Andong 760-749, Korea

出　　处：《Insect Science》2016年第2期235-244,共10页昆虫科学（英文版）

摘　　要：Polydnaviruses （PDVs） are a group of insect DNA viruses, which exhibit a mutual symbiotic relationship with their specific host wasps. Moreover, most encapsidated genes identified so far in PDVs share homologies with insect-originated genes, but not with virus-originated genes. In the meantime, PDVs associated with 2 wasp genera Cotesia and Glytapanteles encode some genes presumably originated from other viruses. Cotesia plutellae bracovirus （CpBV） encodes 4 genes homologous to baculoviral p94： CpBV- E94k1, CpB V-E94k2, CpB V-E94k3, and CpB V-E94k4. This study was conducted to predict the origin of CpB V-E94ks by comparing their sequences with those ofbaculoviral orthologs and to determine the physiological functions by their transient expressions in nonparasitized larvae and subsequent specific RNA interference. Our phylogenetic analysis indicated that CpBV-E94ks were clustered with other E94ks originated from different PDVs and shared high similarity with betabaculoviral p94s. These 4 CpBV genes were expressed during most developmental stages of the larvae of Plutella xylostella parasitized by C. plutellae. Expression of these 4 E94ks was mainly detected in hemocytes and fat body. Subsequent functional analysis by in vivo transient expression showed that all 4 viral genes significantly inhibited both host immune and developmental processes. These results suggest that CpB 11- E94ks share an origin with betabaculoviral p94s and play parasitic roles in suppressing host immune and developmental processes.Polydnaviruses （PDVs） are a group of insect DNA viruses, which exhibit a mutual symbiotic relationship with their specific host wasps. Moreover, most encapsidated genes identified so far in PDVs share homologies with insect-originated genes, but not with virus-originated genes. In the meantime, PDVs associated with 2 wasp genera Cotesia and Glytapanteles encode some genes presumably originated from other viruses. Cotesia plutellae bracovirus （CpBV） encodes 4 genes homologous to baculoviral p94： CpBV- E94k1, CpB V-E94k2, CpB V-E94k3, and CpB V-E94k4. This study was conducted to predict the origin of CpB V-E94ks by comparing their sequences with those ofbaculoviral orthologs and to determine the physiological functions by their transient expressions in nonparasitized larvae and subsequent specific RNA interference. Our phylogenetic analysis indicated that CpBV-E94ks were clustered with other E94ks originated from different PDVs and shared high similarity with betabaculoviral p94s. These 4 CpBV genes were expressed during most developmental stages of the larvae of Plutella xylostella parasitized by C. plutellae. Expression of these 4 E94ks was mainly detected in hemocytes and fat body. Subsequent functional analysis by in vivo transient expression showed that all 4 viral genes significantly inhibited both host immune and developmental processes. These results suggest that CpB 11- E94ks share an origin with betabaculoviral p94s and play parasitic roles in suppressing host immune and developmental processes.

关 键 词：BACULOVIRUS Cotesia plutellae CpBV-E94k Plutella xylostella polyd-navirus 

分 类 号：S476.3[农业科学—农业昆虫与害虫防治] Q78[农业科学—植物保护]