Transcriptional profiling of midgut immunity response and degeneration in the wandering silkworm, Bombyx mori.
Transcriptional profiling of midgut immunity response and degeneration in the wandering silkworm, Bombyx mori.
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DOI：
10.1371/journal.pone.0043769
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Ling E
中科院分区：
文献类型：
--
作者：
Xu Q;Lu A;Xiao G;Yang B;Zhang J;Li X;Guan J;Shao Q;Beerntsen BT;Zhang P;Wang C;Ling E
与脊椎动物相比，鳞翅目昆虫在其生活史中具有一个由多个变态阶段组成的独特的发育过程。与大多数鳞翅目昆虫在成虫阶段以花蜜为生不同，家蚕成虫不吃任何东西，产卵后死亡。此外，鳞翅目昆虫的中肠产生抗菌蛋白在游走阶段，当幼虫组织经历许多变化。造成这些现象的确切机制尚不清楚。我们以家蚕为模型，对摄食期和游走期的中肠进行了全基因组转录谱分析。游行期中肠代谢、消化、离子和小分子转运等相关基因表达下调，表明游行期中肠功能丧失。微阵列分析、qRT-PCR和蛋白质印迹证明了在游动阶段期间中肠中产生抗菌蛋白（肽）。免疫缺陷（Imd）途径的不同基因在游走阶段上调。然而，一些属于Toll途径的关键基因的转录水平没有变化。与蝴蝶不同，蚕蛾的中肠有一层细胞，表明中肠从游走期开始的发育是不寻常的。在游动阶段，中肠的细胞分裂只观察了很短的时间。但在化蛹前，细胞凋亡现象明显。细胞分裂和凋亡的失衡可能是家蚕中肠自游走期开始不断退化的原因。本研究为家蚕游走期中肠的退化和天然免疫相关蛋白的产生机制提供了新的认识。细胞分裂和凋亡的失衡导致中肠不可逆的变性。Imd途径可能调节游走阶段中肠抗菌肽的产生。
Lepidoptera insects have a novel development process comprising several metamorphic stages during their life cycle compared with vertebrate animals. Unlike most Lepidoptera insects that live on nectar during the adult stage, the Bombyx mori silkworm adults do not eat anything and die after egg-laying. In addition, the midguts of Lepidoptera insects produce antimicrobial proteins during the wandering stage when the larval tissues undergo numerous changes. The exact mechanisms responsible for these phenomena remain unclear. We used the silkworm as a model and performed genome-wide transcriptional profiling of the midgut between the feeding stage and the wandering stage. Many genes concerned with metabolism, digestion, and ion and small molecule transportation were down-regulated during the wandering stage, indicating that the wandering stage midgut loses its normal functions. Microarray profiling, qRT-PCR and western blot proved the production of antimicrobial proteins (peptides) in the midgut during the wandering stage. Different genes of the immune deficiency (Imd) pathway were up-regulated during the wandering stage. However, some key genes belonging to the Toll pathway showed no change in their transcription levels. Unlike butterfly (Pachliopta aristolochiae), the midgut of silkworm moth has a layer of cells, indicating that the development of midgut since the wandering stage is not usual. Cell division in the midgut was observed only for a short time during the wandering stage. However, there was extensive cell apoptosis before pupation. The imbalance of cell division and apoptosis probably drives the continuous degeneration of the midgut in the silkworm since the wandering stage. This study provided an insight into the mechanism of the degeneration of the silkworm midgut and the production of innate immunity-related proteins during the wandering stage. The imbalance of cell division and apoptosis induces irreversible degeneration of the midgut. The Imd pathway probably regulates the production of antimicrobial peptides in the midgut during the wandering stage.