scholarly journals Transcriptome characterization analysis and molecular profiles of obligatory diapause induction of the Chinese citrus fruit fly,Bactrocera minax(Diptera: Tephritidae)

2019 ◽  
Author(s):  
Zhixiong Zhou ◽  
Xiaolin Dong ◽  
Chuanren Li

AbstractThe Chinese citrus fruit fly,Bactrocera minax, is a devastating citrus pest in China, Bhutan and India. It will enter obligatory pupal diapause in each generation at specific stage, while little is known about the course and the molecular mechanisms of diapause induction. To gain insight into possible mechanisms of obligatory pupal diapause induction, high-throughput RNA-seq data were generated from second-instar larvae (2L), third-instar larvae (3L) and pupal (P, one week after pupating). A total of 116,402 unigenes were assembled and researched against public databases, and 54,781 unigenes matched to proteins in the NCBI database using the BLAST search. Three pairwise comparisons were performed, and significantly differentially regulated transcripts were identified. Several differentially expressed genes (DEGs) expression patterns revealed that those highly or lowly expressed genes in pupal stage were predicted to be involved in diapause induction. Moreover, GO function and KEGG pathway analysis were performed on all DEGs and showed that 20-hydroxyecdysone (20E) biosynthesis, insulin signaling pathway, FoxO signaling pathway, cell cycle and metabolism pathway may be related to the obligatory diapause of the Chinese citrus fruit fly. This study provides valuable information about the Chinese citrus fruit fly transcriptome for future gene function research, and contributes to the in-depth elucidation of the molecular regulation mechanism of insect obligatory diapause induction.

Insects ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 169 ◽  
Author(s):  
Jia Wang ◽  
Huan Fan ◽  
Pan Wang ◽  
Ying-Hong Liu

The Chinese citrus fly, Bactrocera minax, is a devastating pest of citrus, which enters the obligatory diapause in overwintering pupae to resist harsh environmental conditions. However, little is known about the molecular mechanisms underlying pupal diapause. The previous transcriptomic analysis revealed that a large number of genes were regulated throughout the pupal stage. Of these genes, 12 and six ones that are remarkably up- and downregulated, respectively, specifically in intense diapause were manually screened out in present study. To validate the expression of these genes throughout the pupal stage, the quantitative real-time PCR (qRT-PCR) was conducted, and the genes displaying different expression patterns with those of previous study were excluded. Then, the expressions of remaining genes were compared between diapause-destined and non-diapause-destined pupae to reveal their association with diapause using qRT-PCR and semiquantitative PCR. Finally, five genes, TTLL3B, Cyp6a9, MSTA, Fru, and UC2, and two genes, KSPI and LYZ1, were demonstrated to be positively and negatively associated with diapause, respectively. These findings provide a solid foundation for the further investigation of molecular mechanisms underlying B. minax pupal diapause.


2018 ◽  
Vol 19 (8) ◽  
pp. 2201 ◽  
Author(s):  
Ke Li ◽  
Yongqi Liang ◽  
Libo Xing ◽  
Jiangping Mao ◽  
Zhen Liu ◽  
...  

Adventitious roots (AR) play an important role in the vegetative propagation of apple rootstocks. The potential role of hormone, wounding, and sugar signalling pathways in mediating AR formation has not been adequately explored and the whole co-expression network in AR formation has not been well established in apple. In order to identify the molecular mechanisms underlying AR formation in ‘T337’ apple rootstocks, transcriptomic changes that occur during four stages of AR formation (0, 3, 9 and 16 days) were analyzed using high-throughput sequencing. A total of 4294 differentially expressed genes were identified. Approximately 446 genes related to hormones, wounding, sugar signaling, root development, and cell cycle induction pathways were subsequently selected based on their potential to be involved in AR formation. RT-qPCR validation of 47 genes with known functions exhibited a strong positive correlation with the RNA-seq data. Interestingly, most of the candidate genes involved in AR formation that were identified by transcriptomic sequencing showed auxin-responsive expression patterns in an exogenous Indole-3-butyric acid (IBA)-treatment assay: Indicating that endogenous and exogenous auxin plays key roles in regulating AR formation via similar signalling pathways to some extent. In general, AR formation in apple rootstocks is a complex biological process which is mainly influenced by the auxin signaling pathway. In addition, multiple hormones-, wounding- and sugar-signaling pathways interact with the auxin signaling pathway and mediate AR formation in apple rootstocks.


2018 ◽  
Author(s):  
Alena Boos ◽  
Jutta Distler ◽  
Heike Rudolf ◽  
Martin Klingler ◽  
Ezzat El-Sherif

AbstractGap genes mediate the division of the anterior-posterior axis of insects into different fates through regulating downstream hox genes. Decades of tinkering the segmentation gene network of the long-germ fruit fly Drosophila melanogaster led to the conclusion that gap genes are regulated (at least initially) through a threshold-based French Flag model, guided by both anteriorly- and posteriorly-localized morphogen gradients. In this paper, we show that the expression patterns of gap genes in the intermediate-germ beetle Tribolium castaneum are mediated by a threshold-free ‘Speed Regulation’ mechanism, in which the speed of a genetic cascade of gap genes is regulated by a posterior gradient of the transcription factor Caudal. We show this by re-inducing the leading gap gene (namely, hunchback) resulting in the re-induction of the gap gene cascade at arbitrary points in time. This demonstrates that the gap gene network is self-regulatory and is primarily under the control of a posterior speed regulator in Tribolium and possibly all insects.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhixiong Zhou ◽  
Xiaolin Dong ◽  
Qi Su ◽  
Zhenzhou Xia ◽  
Zailing Wang ◽  
...  

Abstract The Chinese citrus fruit fly, Bactrocera minax (Enderlein), is an economically important pest of citrus. The fly has an obligatory pupal diapause in soil from November to March. However, techniques for predicting or determining the emergence of the adult have, thus far, not been well documented. In this study, we investigated the effects of different pre-diapause temperatures (8, 12, 16, and 20°C) and pupal body weight (five groups according to pupal weight: G-58, 55.0–61.0 mg; G-68, 65–71 mg; G-78, 75–81 mg; G-88, 85–91 mg; G-95, 92–98 mg) on pupal period (the indicator of diapause intensity). The pupal period of B. minax larvae pupated at 8°C was 193.41 d, which was significantly shorter than that of larvae incubated at higher temperatures, suggesting that there was a lower diapause intensity for larvae pupated at lower pre-diapause temperatures. There were also significant differences in the pupal periods at different pupal body weights. The pupal period of G-58 was significantly shorter than that of the heavier groups (G-88 and G-95), and the pupal period increased with increasing pupal body weight in the five groups. Moreover, the pupal period of B. minax significantly and positively correlated to pupal body weight. These findings demonstrate that the pre-diapause temperature and pupal body weight are suitable indicators for predicting the pupal period of overwintering individuals, and the results of this study will contribute to the development of new and effective strategies for predicting the occurrence and population dynamics of B. minax adult.


2007 ◽  
Vol 97 (3) ◽  
pp. 219-223 ◽  
Author(s):  
A. Kurban ◽  
H. Yoshida ◽  
Y. Izumi ◽  
S. Sonoda ◽  
H. Tsumuki

AbstractHelicoverpa armigera (Hübner) exhibits a facultative pupal diapause, which depends on temperature and photoperiod. Pupal diapause is induced at 20°C by short photoperiods and inhibited by long photoperiods during the larval stage. However, in some pupae (35% of males and 57% of females) of a non-selected field population from Okayama Prefecture (34.6°N), diapause is not induced by short photoperiods. In the present experiment, the importance of temperature for diapause induction was studied in the non-diapausing strain, which was selected from such individuals reared at 20°C under a short photoperiod of 10L:14D. Furthermore, the sensitive stage for thermal determination of pupal diapause was determined by transferring larvae of various instars and pupae between 20°C and 15°C. Diapause was induced by 15°C without respect to photoperiod. When larvae or pupae reared from eggs at 20°C under a short or a long photoperiod were transferred to 15°C in the periods of the middle fifth instar to the first three days after pupation, the diapause induction rate was significantly reduced in both males and females, especially in females. In contrast, when larvae or pupae reared at 15°C were transferred to 20°C in the same periods, diapause was induced in males, but not in females. However, the diapause induction rate of pupae transferred to 20°C on the fourth day after pupation was significantly increased in females. The results show that temperature is the major diapause cue in the photoperiod-insensitive strain and the periods of middle fifth larval instar to early pupal stage are the thermal sensitive stages for pupal diapause induction with some different responses to temperatures between males and females in H. armigera.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takeshi Yokoyama ◽  
Shigeru Saito ◽  
Misato Shimoda ◽  
Masakazu Kobayashi ◽  
Yoko Takasu ◽  
...  

AbstractThe bivoltine strain of the domestic silkworm, Bombyx mori, has two generations per year. It shows a facultative diapause phenotype determined by environmental conditions, including photoperiod and temperature, and nutrient conditions during embryonic and larval development of the mother. However, it remains unclear how the environmental signals received during development are selectively utilized as cues to determine alternative diapause phenotypes. We performed a comparative analysis between the Kosetsu strain of B. mori and a Japanese population of the wild mulberry silkworm B. mandarina concerning the hierarchical molecular mechanisms in diapause induction. Our results showed that for the Kosetsu, temperature signals during the mother’s embryonic development predominantly affected diapause determination through the thermosensitive transient receptor potential ankyrin 1 (TRPA1) and diapause hormone (DH) signaling pathways. However, embryonic diapause in B. mandarina was photoperiod-dependent, although the DH signaling pathway and thermal sensitivity of TRPA1 were conserved within both species. Based on these findings, we hypothesize that TRPA1-activated signals are strongly linked to the signaling pathway participating in diapause induction in Kosetsu to selectively utilize the temperature information as the cue because temperature-dependent induction was replaced by photoperiodic induction in the TRPA1 knockout mutant.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Anu Joseph ◽  
S. Parvathy ◽  
Koyikkal Karthikeya Varma

Insulin resistance is a state of impaired responsiveness to insulin action. This condition not only results in deficient glucose uptake but increases the risk for cardiovascular diseases (CVD), stroke, and obesity. The present work investigates the molecular mechanisms of high carbohydrate and fat diet in inducing prediabetic hyperinsulinemia and effect of exercise on InsR signaling events, muscular AChE, and lactate dehydrogenase activity. Adult male Wistar rats were divided into the control (C) diet group, high-carbohydrate diet (HCD) group, high-fat diet (HFD) group, and HCD and HFD groups with exercise (HCD Ex and HFD Ex, respectively). Acetyl choline esterase activity, lactate dehydrogenase activity, total lactate levels, IRS1 phosphorylations, and Glut4 expression patterns were studied in the muscle tissue among these groups. High carbohydrate and fat feeding led to hyperinsulinemic status with reduced acetylcholine esterase (AChE) activity and impaired phosphorylation of IRS1 along with increased lactate concentrations in the muscle. Exercise significantly upregulated phosphoinositide 3 kinase (PI3K) docking site phosphorylation and downregulated the negative IRS1 phosphorylations thereby increasing the glucose transporter (GLUT) expressions and reducing the lactate accumulation. Also, the levels of second messengers like IP3 and cAMP were increased with exercise. Increased second messenger levels induce calcium release thereby activating the downstream pathway promoting the translocation of GLUT4 to the plasma membrane. Our results showed that the metabolic and signaling pathway dysregulations seen during diet-induced hyperinsulinemia, a metabolic condition seen during the early stages in the development of prediabetes, were improved with vigorous physical exercise. Thus, exercise can be considered as an excellent management approach over drug therapy for diabetes and its complications.


Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 753
Author(s):  
Jing Gao ◽  
San-Sheng Jin ◽  
Yan He ◽  
Jin-Hong Luo ◽  
Chun-Qin Xu ◽  
...  

Asian honey bee (Apis cerana) is the most important Chinese indigenous species, while its toxicological characteristic against neonicotinoids is poorly known. Here, we combined physiological experiments with a genome-wide transcriptome analysis to understand the molecular basis of genetic variation that responds to sublethal imidacloprid at different exposure durations in A. cerana. We found that LC5 dose of imidacloprid had a negative impact on climbing ability and sucrose responsiveness in A. cerana. When bees were fed with LC5 dose of imidacloprid, the enzyme activities of P450 and CarE were decreased, while the GSTs activity was not influenced by the pesticide exposure. The dynamic transcriptomic profiles of A. cerana workers exposed to LC5 dose of imidacloprid for 1 h, 8 h, and 16 h were obtained by high-throughput RNA-sequencing. We performed the expression patterns of differentially expressed genes (DEGs) through trend analysis, and conducted the gene ontology analysis and KEGG pathway enrichment analysis with DEGs in up- and down-regulated pattern profiles. We observed that more genes involved in metabolism, catalytic activity, and structural molecule activity are down-regulated; while more up-regulated genes were enriched in terms associated with response to stimulus, transporter activity, and signal transducer activity. Additionally, genes related to the phenylalanine metabolism pathway, FoxO signaling pathway, and mTOR signaling pathway as indicated in the KEGG analysis were significantly up-related in the exposed bees. Our findings provide a comprehensive understanding of Asian honey bee in response to neonicotinoids sublethal toxicity, and could be used to further investigate the complex molecular mechanisms in Asian honey bee under pesticide stress.


2021 ◽  
Author(s):  
Takeshi Yokoyama ◽  
Shigeru Saito ◽  
Misato Shimoda ◽  
Masakazu Kobayashi ◽  
Yoko Takasu ◽  
...  

Abstract The bivoltine strain of the domestic silkworm, Bombyx mori, has two generations per year. It shows a facultative diapause phenotype determined by environmental conditions, including photoperiod and temperature, and nutrient conditions during embryonic and larval development of the mother. However, it remains unclear how the environmental signals received during development are selectively utilized as cues to determine alternative diapause phenotypes. We performed a comparative analysis between the Kosetsu strain of B. mori and a Japanese population of the wild mulberry silkworm B. mandarina concerning the hierarchical molecular mechanisms in diapause induction. Our results showed that for the Kosetsu, temperature signals during the mother’s embryonic development predominantly affected diapause determination through the thermosensitive transient receptor potential ankyrin 1 (TRPA1) and diapause hormone (DH) signaling pathways. However, embryonic diapause in B. mandarina was photoperiod-dependent, although the DH signaling pathway and thermal sensitivity of TRPA1 were conserved within both species. Based on these findings, we hypothesize that TRPA1-activated signals are strongly linked to the signaling pathway participating in diapause induction in Kosetsu to selectively utilize the temperature information as the cue because temperature-dependent induction was replaced by photoperiodic induction in the TRPA1 knockout mutant.


1994 ◽  
Vol 71 (3) ◽  
pp. 257-261 ◽  
Author(s):  
Tetsuya Yasuda ◽  
Minora Narahara ◽  
Seiji Tanaka ◽  
Sadao Wakamura

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