番茄潜叶蛾神经肽的鉴定与序列分析

Identification and sequence analysis of neuropeptides of tomato leaf-miner,Tuta absoluta

【目的】神经肽是细胞间重要的信号调控分子,在调节昆虫多种生理和行为过程中起着关键作用。番茄潜叶蛾Tuta absoluta是一种新近入侵我国的重大毁灭性害虫,为深入解析番茄潜叶蛾的神经肽组成及其变异特征,本研究对其神经肽基因进行了系统的鉴定和序列分析。【方法】通过同源比对方法检索番茄潜叶蛾基因组数据,筛选出编码神经肽的基因,并进行信号肽预测、成熟肽预测、保守基序分析和序列变异分析。【结果】在番茄潜叶蛾基因组中共鉴定出56个神经肽基因,这些基因的类别与其他鳞翅目昆虫一致,但一些基因在数量上存在差异。如鉴定到1个脂肪动员激素(Adipokinetic hormones,AKH)基因、2个利尿激素(Diuretic hormone,DUH)家族基因和8个胰岛素样肽(Insulin-like peptide,ILP)基因,均少于其他昆虫。促前胸腺激素(Prothoraticotropic hormone,PTTH)基因在番茄潜叶蛾中扩张到3个转录本,其他鳞翅目昆虫通常只有1个。信息素合成激活肽(Pheromonebiosynthesisactivating neuropeptide,PBAN)和胰岛素样肽基因表现出不同寻常的结构变异,其中,信息素合成激活肽预测可以切割出9个成熟神经肽,其他鳞翅目昆虫只能切割出5个。虽然胰岛素样肽ILP(Tabs017372.1)未预测到神经肽切割位点,但仍预测到包含A链和B链的保守半胱氨酸位点。此外,生殖素(Natalisin)在番茄潜叶蛾中具有最多数量的成熟肽,达17个。【结论】本研究对番茄潜叶蛾的神经肽基因进行了详细的统计和分析,发现促前胸腺激素、信息素合成激活肽和胰岛素样肽等存在一定程度变异,可能具有独特的调控机制。深入研究这些神经肽基因的表达和功能,有助于揭示其在昆虫生理中的作用,并为昆虫生态控制提供新思路。

[Aim]Neuropeptides are crucial signaling molecules between cells that regulate various physiological and behavioral processes in insects.The tomato leafminer,Tuta absoluta,is a recently invasive and highly destructive pest in China.To better understand the composition and variation of neuropeptides in T.absoluta,this study systematically identified and analyzed the neuropeptide genes of this species.[Methods]Neuropeptide-encoding genes were screened from T.absoluta genome data using homology-based searches.Subsequent analyses included signal peptide prediction,mature peptide prediction,conserved motif analysis,and sequence variation analysis.[Results]A total of 56 neuropeptide genes were identified in the T.absoluta genome.The categories of identified neuropeptide genes were consistent with those in other Lepidopterans,though some differences in quantity were noted.For example,only one adipokinetic hormone(AKH)gene,two diuretic hormone(DUH)genes,and eight insulin-like peptide(ILP)genes were identified,all of which are fewer than the number found in other insects.Conversely,the prothoracicotropic hormone(PTTH)gene has three transcripts in T.absoluta,whereas typically only one transcript is found in other insects.The pheromone biosynthesis activating neuropeptide(PBAN)and insulin-like peptide genes also exhibited unusual structural variations.PBAN was predicted to cleave into nine mature neuropeptides,whereas in other Lepidopterans this typically cleaves into only five.In addition,the insulin-like peptide ILP(Tabs017372.1)did not have a predicted neuropeptide cleavage site but still contained conserved cysteine residues in the A and B chains.Furthermore,natalisin in T.absoluta had the highest number of mature peptides(up to 17).[Conclusion]This study provides a detailed identification and analysis of neuropeptide genes in T.absoluta,revealing significant variations in PTTH,PBAN,and ILP that may indicate unique regulatory mechanisms.Understanding the expression and function of these neuropeptide genes will shed light on their roles in insect physiology and provide new insights for ecological pest control strategies.