【Aim】 To lay a foundation for exploring the mechanism of digestive physiology of Hyphantria cunea (Drury) in host transformation. 【Methods】 We first cloned a serine protease gene by screening the H. cunea cDNA library. We then analyzed the expression patterns of this gene in different developmental stages of H.cunea by qPCR. The distribution and expression patterns of this gene in different tissues of the 5th instar larvae of H.cunea were analyzed by semi-quantitative RT-PCR and qPCR, respectively, and the expression patterns in the 4th instar larvae of H.cunea feeding on leaves of different host species (Populus deltoids, Cerasus serrulata var. lannesiana, Cerasus serrulata, Camptotheca acuminata and Platanus orientalis) were detected by qPCR. 【Results】 A serine protease gene HcSP1 (GenBank accession no.: MH663425) was successfully cloned from H. cunea. The open reading frame (ORF) of HcSP1 is 882 bp in length, encoding 293 amino acids, with the predicted molecular weight (MW) of 30.5 kD and the theoretical isoelectric point (pI) of 9.86. The predicted N-terminal hydrophobic region contains signal peptide consisting of 15 amino acid residues. The protein encoded by HcSP1 contains the enzyme activity catalytic center formulated with His, Asp and Ser residues, which is a typical feature of serine proteases. HcSP1 also possesses some typical features of putative trypsin precursors, such as containing a signal peptide, activation peptide and conserved N-terminus (IVGG). The NCBI BLAST alignment revealed that the amino acid sequence identities between HcSP1 of H. cunea and other lepidopteran serine proteases are between 50% and 70%. The qPCR results indicated that the expression of HcSP1 inH. cunea in different developmental stages showed dynamic change, increasing with the larval instar. Semi-quantitative RT-PCR results showed that HcSP1 was expressed in various tissues of the 5th instar larva of H. cunea including head, salivary gland, midgut, fat body, cuticle, Malpighian tubules and hemolymph, and qPCR results further revealed that this gene had the highest expression level in the midgut. The expression level of HcSP1 was significantly higher in larvae of H. cunea feeding on C. acuminata leaves than in larvae feeding on other host plants. 【Conclusion】 In this study, we obtained a serine protease gene HcSP1 inH. cunea, and detected its developmental and tissue expression patterns, and its expression levels in the 4th instar larvae of H. cunea feeding on leaves of different host species. The results lay a foundation for exploring the mechanism of digestive physiology of H. cunea in host transformation, and also provide new insight for the development of new management tools for H. cunea.

 【Aim】 The aim of this study is to analyze the whole process of establishing cell lines from Spodoptera exigua pupal ovarian cells, and to explore the changes of gene expression at the transcriptional level from in vivo to in vitro culture, so as to provide a theoretical basis for the establishment of insect in vitro culture models. 【Methods】 In this study, the transcriptomes of various stages of S. exigua pupal ovarian cells during ex vivo culture were sequenced by using second-generation transcriptome sequencing technology Illumina Hiseq, and the differentially expressed genes and their related signaling pathways were analyzed. The expression of some cell cycle-related genes (cycd and cdk4), regulatory genes (cdc20, apc1, skp2 and mad1), and proliferation-related molecular markers (mcm4 and pcna) in different stages of S. exigua pupal ovarian cells during ex vivo culture were verified by real-time PCR. 【Results】 The process of ex vivo culture of S. exigua pupal ovarian cells includes five stages: anatomical obtaining of ex vivo ovarian tissues, primary cells isolated after adherent culture of ovarian tissues, transformed cells with re-proliferation ability, first generation cells capable of continuous passage, and cell lines capable of continuous passage for more than 15 generations. A total of 46 796 unigene sequences were obtained from the five stages of S. exigua pupal ovarian cells during ex vivo culture by RNA sequencing, with good sequence length integrity of the assembly. The splicing length distribution of unigene sequences was reasonable, and the Q30 of the sample base was above 94%. Based on the KEGG database, 1 473 unigenes were annotated to be involved in 20 signaling pathways closely related to cellular processes, and 92 unigenes in the cell cycle signaling pathway. Cluster analysis showed that the gene expression patterns of ovarian cells in a rapidly developing state in vivo were very close to that of cell lines which were also in a proliferative state. In addition, 619 differentially expressed genes were screened at the critical transformation stage of primary cells from transient stagnant growth to clustered cells. The expression of cdk4 significantly decreased ex vivo, and the expression level of cycd significantly increased after the critical stage of cell transformation. The expression levels of Cdc20, apc1, skp2, and mad1 were significantly higher in ovarian tissues and cell lines than in primary cells, key transformed cells, and first passage cells. From primary cells to passage, the expression level of cycd was significantly increased by 8.7-fold, which was significantly higher than those of mcm4 and pcna. 【Conclusion】 The sequence quality of five stages of S. exigua pupal ovarian cells during ex vivo culture by transcriptome sequencing met with the basic requirements for transcriptome data analysis. The differentially expressed genes in S. exigua pupal ovarian cells during ex vivo culture were obtained. The reverse cell proliferation of primary cells may be related to the expression of cell cycle regulatory genes such as cdk4, cycd, skp2 and mad1. In addition, cycd can be used as a marker for the ability of primary cells to pass through.

 【Aim】 This study aims to investigate the infection of secondary endosymbiont Wolbachia in Aphis gossypii populations from different areas of Henan province, central China, and further to ascertain its infection type and phylogeny. 【Methods】 A. gossypii samples were collected from 13 areas ofHenanprovince during 2016-2017, and identified by amplifying the COI gene. The infection rate of Wolbachia was detected by amplification of the wsp gene sequence from the Wolbachia in different A. gossypii populations. The phylogenetic relationship of Wolbachia in different A. gossypii populations was constructed with neighbor-joining method. 【Results】 The infection rates of Wolbachia in 13 populations of A. gossypii collected from different areas ofHenanprovince were different, being the highest (46.67%) in Zhengzhou (ZZ) population and the lowest (6.67%) in Xinyang 2 (XY2) population. The infection rates of Wolbachia in the 13 populations ranged from 6.67% to 46.67%, with the average value of 28.35%. The phylogenetic relationship based on wsp gene indicated that Wolbachia strains in both Anyang and Xinyang populations of A. gossypii were identified as supergroup B, while those in other populations were supergroup A. 【Conclusion】 The infection rate of Wolbachia in different A. gossypii populations of Henan province varies distinctly, and either supergroup A or B Wolbachia is present in these A. gossypii populations.