中文摘要：

【目的】克隆朱砂叶螨Tetranychus cinnabarinus几丁质合成过程中的关键酶几丁质合成酶基因,并检测该基因在朱砂叶螨生长发育不同阶段的相对表达量。【方法】本研究采用逆转录聚合酶链反应（RT-PCR）以及c DNA末端快速扩增（RACE）技术首次克隆获得朱砂叶螨几丁质合成酶基因1的全长c DNA序列（命名为Tc CHS1,Gen Bank登录号为KM242062）,并使用实时荧光定量PCR技术首次检测了Tc CHS1基因在朱砂叶螨生长发育不同阶段的相对表达量。【结果】朱砂叶螨Tc CHS1基因的c DNA全长为4 881 bp,包括198 bp的5＇非翻译区（5＇-UTR）,4 425 bp的开放阅读框（ORF）,258 bp的3＇非翻译区（3＇-UTR）,开放阅读框编码1 474个氨基酸,预测其蛋白质分子质量约为168.35 ku,理论等电点为6.26。其包含EDR和QRRRW这2个几丁质合成酶基因的标签序列。氨基酸序列同源性分析结果表明：Tc CHS1与其他昆虫该基因编码蛋白的氨基酸序列相似度在50%左右,与二斑叶螨Tetranychus urticae的氨基酸相似度最高（98%）,与西方盲走螨Metaseiulus occidentalis的相似度为55%。分子系统进化的结果也表明Tc CHS1与其他昆虫的CHS1聚在一起,并且和二斑叶螨具有最近的亲缘关系。荧光定量分析表明Tc CHS1基因在朱砂叶螨生长发育的不同阶段（卵、幼螨、第1若螨、第2若螨、雌成螨和雄成螨）均有表达,在卵和雌成螨中的表达量较高,在第2若螨的表达量最低。【结论】Tc CHS1基因可能在朱砂叶螨生长发育过程中具有重要作用。

英文摘要：

[Objectives] To clone the Tetranychus cinnabarinus chitin synthase gene and detect relative levels of the expression of this gene in the different developmental stages of T. cinnabarinus. [Methods] The full-length chitin synthase c DNA of T. cinnabarinus was first cloned by RT-PCR and RACE-PCR, and the relative expression levels of the Tc CHS1 gene were then detected in different developmental stages of T. cinnabarinus using quantative real-time PCR. [Results] Tc CHS1 c DNA was 4 881 bp in length, including a 198 bp 5＇ terminal UTR, 4 425 bp encoding region comprised of 1 474 amino acids and a 258 bp 3＇ terminal UTR. The theoretical molecular weight of Tc CHS1 based on the deduced amino acid sequence was estimated to be 168.35 ku, with an isoelectric point of 6.26. The signature sequences ＂EDR＂ and ＂QRRRW＂ for chitin synthases were found in Tc CHS1. Alignment of the deduced amino acid sequence of Tc CHS1 and those of other insects demonstrated that this shared 98% and 55% similarity with T. urticae and Metaseiulus occidentalis, respectively, and approximately 50% similarity with other insects. Phylogenetic tree analysis revealed that the putative CHS amino acid sequence of T. cinnabarinus showed high similarity with the CHS1 sequences of other insects, and was most closely related to that of T. urticae. Real-time quantitative PCR demonstrated that the Tc CHS1 gene was expressed in different development stages, including eggs, larvae, protonymphs, deutonymphs, adult females and adult males. The result suggest that the Tc CHS1 m RNA were most highly expressed in eggs and adult females, and least expressed in deutonymphs. [Conclusion] The results indicate that Tc CHS1 may play an important role in the growth and development of T. cinnabarinus.