【Aim】 The orange wheat blossom midge, Sitodiplosis mosellana, escapes temperature extremes during hot summer and cold winter by undergoing obligatory larval diapause. This study aims to explore the potential roles of heat shock protein 40 gene (Hsp40) during diapause of S. mosellana. 【Methods】 The full-length cDNA of Hsp40 was cloned from S. mosellana larvae at pre-diapause stage by using RT-PCR and RACE technologies, and its nucleotide and amino acid sequences were subjected to bioinformatic analysis. The mRNA expression level of Hsp40 inpre-diapause, diapause and post-diapause larvae of S. mosellana, over-summering diapausing larvae exposed to short-term heat stress (35-50℃, ≤120 min) and over-wintering diapausing larvae exposed to short-term cold stress (0--15℃, ≤120 min) were detected with real-time quantitative PCR. 【Results】 The full-length cDNA sequence of Hsp40 was obtained from S. mosellana, and named SmHsp40 (GenBank accession number: MH001167), which is 1 553 bp in length and contains a 1 074 bp ORF encoding a protein of 357 amino acids with a predicted molecular weight of 40.87 kD and a theoretical pI of 5.31. The deduced amino acid sequence contains the conserved J-domain and HPD motif of Hsp40 protein family. Multiple sequence alignment and phylogenetic analysis indicated that SmHsp40 was most similar and closely related to Hsp40s from the Nematocera including Anopheles gambiae. The expression of SmHsp40 differed significantly among different diapause stages, and was up-regulated during the diapause period, with significantly higher expression level during summer (July to August) and winter (December to January of the following year). The expression of SmHsp40 was induced in over-summering diapausing larvae exposed to heat stress (40℃for 1 h) or over-wintering diapausing larvae exposed to cold stress (-10℃for 1 h) as compared to the untreated control, but not induced significantly under extreme temperatures higher than45℃or lower than-15℃. 【Conclusion】 SmHsp40 is involved in diapause process of S. mosellana and may contribute to diapause maintenance as well as heat and cold tolerance during diapause.

【Aim】 This study aims to screen out the suitable reference genes for gene expression analysis in different tissues of adult Sympiezomias velatus. 【Methods】 The house-keeping gene sequences of S. velatus were acquired and adopted as the candidate reference genes through transcriptome sequencing technique. Their mRNA expression levels in different tissues (antenna, head, thorax, abdomen and leg) of male and female adults of S. velatus were investigated by qRT-PCR. The expression stabilities of these candidate genes were evaluated by using three software-based (geNorm, NormFinder and BestKeeper) and one web-based (RefFinder) comprehensive analysis tools. And the expression stabilities of the candidate reference genes in different adult tissues of S. velatus were further validated by using the odorant binding protein 1 gene (OBP1) as the target gene. 【Results】 Nine house-keeping genes, including beta-actin gene (ACT), glyceraldehyde-3-phosphate gene (GAPDH), 18S ribosomal RNA (18S rRNA), 60S ribosomal protein L12 gene (RPL12), 60S ribosomal protein L32 gene (RPL32), 40S ribosomal protein S20 gene (RPS20), elongation factor 2 gene (EF2), α-tubulin gene (TUA), and β-tubulin gene (TUB), were identified for the first time based on the S. velatus transcriptome data. It was revealed that RPL12 and RPS20 were the most stable reference genes based on the geNorm analysis, while TUA and TUB were the most stable reference genes based on the BestKeeper analysis and NormFinder analysis, respectively. Comprehensive analysis showed that TUB, TUA, RPS20 and RPL12 were the most stable reference genes, while three of the most widely used reference genes including 18S rRNA, ACT and GAPDH, were the least stable. Finally, the validation result of expression stability of four candidate reference genes with OBP1 as the target gene showed that the expression patterns of OBP1 indifferent tissues of adult S. velatus were basically coincident when TUB and RPL12 acted as the reference genes, while the expression pattern was a little different from that with TUB as the reference gene when RPL32 acted as the reference gene, and completely different from that with TUB as the reference gene when 18S rRNA acted as the reference gene. 【Conclusion】 TUB, TUA, RPS20 and RPL12 proved to be acceptable as reference genes for gene expression analysis in different tissues of adult S. velatus. This study lays a foundation for future studies on gene expression in S. velatus.

The innate immunity of insects includes cellular immunity and hurmoral immunity. Recent studies have shown that 20-hydroxyecdysone (20E), one of the key hormones in the regulation of insect growth and development, is involved in the regulation of insect innate immunity. In this article we focus on the molecular mechanisms of 20E regulating the innate immunity in insects and the influence of microorganisms on 20E titer based on the mechanisms of insect immunity. 20E can activate cellular and humoral immunity against invasive microorganisms, and the stimulation of exogenous microorganisms can promote the increase of 20E titer by 3-dehydroecdysteroid-3β-reductase (3DE-3β-reductase). 20E has a significant effect on the immune system of insects, and the increase of its titer can activate cellular immunity, including phagocytosis, encapsulation and nodulation, while the effect on humoral immunity is more complex. Besides accelerating melanization, whether 20E promotes or inhibits the expression of antimicrobial peptides is not clear yet. Researchers identified a number of key genes through which 20E regulates humoral immunity, and they can be grouped into three categories according to the pathways they are involved in: the first is dependent on innate immune pathways such as Toll and IMD, the second is dependent on insulin signaling pathways, and the third is the direct regulation by 20E signaling pathway via such transcription factors as BR-C. However, the way these pathway factors interact with each other and their molecular regulatory mechanisms are still unclear and deserve further study.

Diapause is an adaptive developmental strategy and state adopted by insects to survive in challenging environments. The silkworm, Bombyx mori, is a typical egg diapause insect, and the diapause happens in the early stages of its embryonic development. The diapause hormone (DH) is secreted by the suboesophageal ganglion of B. mori, playing a key role in the process of egg diapause. DH transmits signals via diapause hormone receptor (DHR) on the surface of silkworm ovarian cells, regulating the material metabolism and then determining the diapause of eggs. In this article, we summarized the discovery process and structure and function of DH, reviewed the gene cloning and expression, signal transduction and mechanism of DHR in the silkworm, and put forward the research prospects. It is expected to provide a molecular theoretical basis for studying the whole process of induction, inhibition and termination of embryonic diapause and further utilizing silkworm embryo diapause to improve the technology of traditional silkworm rearing.

As eusocial insect, Apis mellifera is one of the ideal models for studying human cognitive behavior. In a normal colony, workers show agedependent behavioral transition. Workers are mainly engaged in the work in nest in three weeks after emergence, and then they start to work outside the colony, especially to collect pollen and nectar. The behavioral transition of workers from working in nest to working outside is related to many factors. In this article, we reviewed the progress in the research on the behavioral transition of honeybees resulted from colony environment, physiology and expression change of genes including mRNAs and microRNAs, hoping to provide references for further exploring the factors and mechanisms regulating the behavioral transition of honeybees.

 【Aim】 This study aims to investigate the gene controlling the eye color of the white-backed planthopper (WBPH), Sogatella furcifera and to explore the potential influence of eye color mutants on mating capacity. 【Methods】 An orange-eye mutant was established in our insectary, and the gene symbol related to this mutant was designated as org. The genetic basis of this phenotype was determined by designing eight groups of cross-mating experiment containing three genotypes (+/+, +/org, org/org). Whether the eye color related genes influence the mating capacity in WBPH was tested in a mating competition experiment. 【Results】 This orange-eye mutant had a pair of bright orange ommatea which was distinctly different from the wild type WBPH. The orange-eye phenotype occurred in all developmental stages of WBPH: the eyespot of eggs (3 d after ovipisition) and the compound eyes of nymphs and adults of both sexes and wing morphs. Reciprocal crosses between homozygous normal-eye WBPH and orange-eye WBPH produced F₁ progeny with only normal-eye color. The sex ratio in the offspring produced from all groups was not biased to a specific sex based on Chi-square test (α=0.05, χ²_c=0.19-1.53). The mating competitiveness of the orange-eye mutant was significantly weaker than that of the wild type phenotype in WBPH. 【Conclusion】 Our results indicate that the inheritance of the orange-eye trait is controlled by an autosomal recessive allele, and eye color related gene has significant impacts on mating capacity in WBPH.