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Shutang Zhou - One of the best experts on this subject based on the ideXlab platform.

  • clustered mir 2 mir 13a mir 13b and mir 71 coordinately target notch gene to regulate oogenesis of the migratory locust locusta migratoria
    2019
    Co-Authors: Jiasheng Song, Haihong Zhao, Shutang Zhou
    Abstract:

    Abstract MicroRNAs (miRNAs), ∼22-nt small noncoding RNAs with a crucial role in various biological processes of organisms, are usually clustered in the genome. However, little is known about the miRNA clusters involved in Insect Reproduction. By small RNA sequencing and quantification followed by qRT-PCR , we found that the expression of invertebrate-specific miR-2/13/71 cluster including miR-2, miR-13a, miR-13b and miR-71 significantly decreased after adult ecdysis of the migratory locust , Locusta migratoria . Luciferase reporter assay and RNA immunoprecipitation demonstrated that miR-2/13/71 bound to the protein coding sequence of Notch and downregulated its expression. Injection of miR-2/13/71 agomiRs led to significant decrease of Notch expression as well as markedly reduced levels of Vitellogenin mRNA, suppressed oocyte maturation and impaired ovarian growth. Moreover, the expression of miR-2/13/71 was repressed by juvenile hormone (JH). Our results thus point to a previously unidentified mechanism by which JH-repressed miR-2/13/71 coordinately downregulates Notch to modulate Insect Reproduction. The increase of JH and decrease of miR-2/13/71 expression in both previtellogenic and vitellogenic stages of adult females ensure a high level of Notch expression, critically contributing to JH-dependent vitellogenesis and oogenesis .

  • juvenile hormone dependent kazal type serine protease inhibitor greglin safeguards Insect vitellogenesis and egg production
    2019
    Co-Authors: Wei Guo, Lianfeng Zhao, Libin Yang, Zhaokui Cai, Shutang Zhou
    Abstract:

    In addition to preventing Insect metamorphosis, juvenile hormone (JH) is known to stimulate aspects of Insect Reproduction. However, the molecular mechanisms of JH action in Insect Reproduction remain largely unknown. By reanalyzing the transcriptomic data from adults and other developmental stages of the migratory locust Locusta migratoria, we identified a gene coding for Kazal-type protease inhibitor, previously named Greglin. Greglin is specifically expressed in adult females and most abundant in the fat body and ovaries. Interestingly, Greglin is among the top 3 of highly expressed genes in adult female locusts, after 2 vitellogenin ( Vg) genes. Greglin is induced by JH and expressed at remarkably high levels in the vitellogenic stage. Knockdown of Greglin in adult female locusts results in accelerated degradation of serine protease substrate and significantly reduced levels of Greglin protein in hemolymph and ovaries. The consequent phenotypes include blocked oocyte maturation, arrested ovarian growth and shrunken follicular epithelium, as well as declines in egg number and hatchability. The data provide the first evidence, to our knowledge, that JH-dependent Greglin is involved in locust vitellogenesis and oocyte maturation likely by protecting vitellogenesis and other forms of yolk precursors from proteolysis. The result offers new insights into the regulation of JH and function of protease inhibitors in Insect vitellogenesis, oocyte maturation and fecundity.-Guo, W., Wu, Z., Yang, L., Cai, Z., Zhao, L., Zhou, S. Juvenile hormone-dependent Kazal-type serine protease inhibitor Greglin safeguards Insect vitellogenesis and egg production.

  • juvenile hormone differentially regulates two grp78 genes encoding protein chaperones required for Insect fat body cell homeostasis and vitellogenesis
    2017
    Co-Authors: Maowu Luo, Wei Guo, Zhiming Wang, Le Kang, Shutang Zhou
    Abstract:

    Juvenile hormone (JH) has a well known role in stimulating Insect vitellogenesis (i.e. yolk deposition) and oocyte maturation, but the molecular mechanisms of JH action in Insect Reproduction are unclear. The 78-kDa glucose-regulated protein (Grp78) is a heat shock protein 70-kDa family member and one of the most abundant chaperones in the endoplasmic reticulum (ER) where it helps fold newly synthesized peptides. Because of its prominent role in protein folding, and also ER stress, we hypothesized that Grp78 might be involved in fat body cell homeostasis and vitellogenesis and a regulatory target of JH. We report here that the migratory locust Locusta migratoria possesses two Grp78 genes that are differentially regulated by JH. We found that Grp78-1 is regulated by JH through Mcm4/7-dependent DNA replication and polyploidization, whereas Grp78-2 expression is directly activated by the JH-receptor complex comprising methoprene-tolerant and Taiman proteins. Interestingly, Grp78-2 expression in the fat body is about 10-fold higher than that of Grp78-1 Knockdown of either Grp78-1 or Grp78-2 significantly reduced levels of vitellogenin (Vg) protein, accompanied by retarded maturation of oocytes. Depletion of both Grp78-1 and Grp78-2 resulted in ER stress and apoptosis in the fat body and in severely defective Vg synthesis and oocyte maturation. These results indicate a crucial role of Grp78 in JH-dependent vitellogenesis and egg production. The presence and differential regulation of two Grp78 genes in L. migratoria likely help accelerate the production of this chaperone in the fat body to facilitate folding of massively synthesized Vg and other proteins.

  • juvenile hormone activates the transcription of cell division cycle 6 cdc6 for polyploidy dependent Insect vitellogenesis and oogenesis
    2016
    Co-Authors: Wei Guo, Yingtian Xie, Shutang Zhou
    Abstract:

    Although juvenile hormone (JH) is known to prevent Insect larval metamorphosis and stimulate adult Reproduction, the molecular mechanisms of JH action in Insect Reproduction remain largely unknown. Earlier, we reported that the JH-receptor complex, composed of methoprene-tolerant and steroid receptor co-activator, acts on mini-chromosome maintenance (Mcm) genes Mcm4 and Mcm7 to promote DNA replication and polyploidy for the massive vitellogenin (Vg) synthesis required for egg production in the migratory locust (Guo, W., Wu, Z., Song, J., Jiang, F., Wang, Z., Deng, S., Walker, V. K., and Zhou, S. (2014) PLoS Genet. 10, e1004702). In this study we have investigated the involvement of cell-division-cycle 6 (Cdc6) in JH-dependent vitellogenesis and oogenesis, as Cdc6 is essential for the formation of prereplication complex. We demonstrate here that Cdc6 is expressed in response to JH and methoprene-tolerant, and Cdc6 transcription is directly regulated by the JH-receptor complex. Knockdown of Cdc6 inhibits polyploidization of fat body and follicle cells, resulting in the substantial reduction of Vg expression in the fat body as well as severely impaired oocyte maturation and ovarian growth. Our data indicate the involvement of Cdc6 in JH pathway and a pivotal role of Cdc6 in JH-mediated polyploidization, vitellogenesis, and oogenesis.

  • kruppel homolog 1 mediates juvenile hormone action to promote vitellogenesis and oocyte maturation in the migratory locust
    2014
    Co-Authors: Jiasheng Song, Zhiming Wang, Shun Deng, Shutang Zhou
    Abstract:

    Juvenile hormone (JH) prevents Insect larval metamorphosis and stimulates processes for adult Reproduction. Kruppel-homolog 1 (Kr-h1), a zinc finger transcription factor, is shown to mediate the anti-metamorphic effect of JH in both holometabolous and hemimetabolous Insects. However, the role of Kr-h1 in JH-mediated Reproduction has not been determined. Using the migratory locust, Locusta migratoria, we showed here that Kr-h1 was expressed in response to JH in female adults, and Kr-h1 transcription was directly regulated by the JH-receptor complex comprised of Methoprene-tolerant (Met) and steroid receptor co-activator. We demonstrated that Kr-h1 RNAi phenocopied Met RNAi and JH-deprived condition during post-eclosion development and vitellogenesis of female locusts. Knockdown of Kr-h1 resulted in substantial reduction of Vg expression in the fat body and lipid accumulation in the primary oocytes, accompanied by blocked follicular epithelium development, oocyte maturation and ovarian growth. Our data therefore reveal a crucial role of Kr-h1 in Insect vitellogenesis and egg production. This study suggests that JH-Met-Kr-h1 signaling pathway is also functional in Insect Reproduction.

Stephen S Tobe - One of the best experts on this subject based on the ideXlab platform.

  • methoprene tolerant met knockdown in the adult female cockroach diploptera punctata completely inhibits ovarian development
    2014
    Co-Authors: Elisabeth Marchal, Ekaterina F Hult, Juan Huang, Zhenguo Pang, Barbara Stay, Stephen S Tobe
    Abstract:

    Independent of the design of the life cycle of any Insect, their growth and Reproduction are highly choreographed through the action of two versatile hormones: ecdysteroids and juvenile hormones (JH). However, the means by which JH can target tissues and exert its pleiotropic physiological effects is currently still not completely elucidated. Although the identity of the one JH receptor is currently still elusive, recent evidence seems to point to the product of the Methoprene-tolerant gene (Met) as the most likely contender in transducing the action of JH. Studies on the role of this transcription factor have mostly been focused on immature Insect stages. In this study we used the viviparous cockroach Diploptera punctata, a favorite model in studying JH endocrinology, to examine the role of Met during Reproduction. A tissue distribution and developmental profile of transcript levels was determined for Met and its downstream partners during the first gonadotropic cycle of this cockroach. Using RNA interference, our study shows that silencing Met results in an arrest of basal oocyte development; vitellogenin is no longer transcribed in the fat body and no longer taken up by the ovary. Patency is not induced in these animals which fail to produce the characteristic profile of JH biosynthesis typical of the first gonadotropic cycle. Moreover, the ultrastructure of the follicle cells showed conspicuous whorls of rough endoplasmic reticulum and a failure to form chorion. Our study describes the role of Met on a cellular and physiological level during Insect Reproduction, and confirms the role of Met as a key factor in the JH signaling pathway.

Edward J Bechinski - One of the best experts on this subject based on the ideXlab platform.

  • a new modelling approach to Insect Reproduction with same shape Reproduction distribution and rate summation with particular reference to russian wheat aphid
    2009
    Co-Authors: Z S, Edward J Bechinski
    Abstract:

    Same-shape distribution model and rate summation approach are widely used to describe the Insect developmental process. In this approach, by integrating a nonlinear deterministic developmental rate model and a probabilistic same-shape distribution model, the proportion of the cohort completing development is quantified as a function of accumulating developmental rates, which themselves are temperature dependent. This method is considered to be more accurate in modelling Insect phenology because it can address a well-known biological fact, individual variability, that Insect individual developmental rates respond to temperature differently, and because rate-summation essentially simulates developmental rates under variable temperatures instead of constant temperatures. By comparing Insect development and Reproduction with respect to their responses to temperatures, we argue for the extension of the same-shape and rate-summation approaches to modelling Insect Reproduction process under variable temperatures. We justify our arguments by the fact that individual variation universally exists in almost all biological characteristics, and the phenomenon that Insect development and Reproduction respond to temperature very similarly, which is supported by some endocrinological evidences reported in literature. In addition, the approach for testing the applicability of the original same-shape developmental modelling, experimentally verifying the sameness of the same-shape curves or that the shape of the curves is invariant with respect to the temperature regimes, equally applies to our extended version for Reproduction modelling. We successfully tested the extension and its applicability with our experimental data of 1800 Russian wheat aphids' (RWA) (Diuraphis noxia (Mordvilko)) Reproduction under various temperature and plant growth stage regimes. We also extended Taylor's (1981) nonlinear model for Insect development to describe RWA mean (median) nymphal production under different temperatures and barley plant growth stages. Three same-shape distribution models, Weibull distribution, Stinner's model and logistic model, are used to construct the same-shape Reproduction distribution models for RWA. The extensions performed in this paper contribute a new modelling approach for predicting Insect Reproduction under field variable temperatures and plant growth stages. The prediction model can be parameterized with data from typical laboratory demography experiments and further integrated into simulation models for Insect population dynamics. Finally, we discussed why the sameness test of the same-shape distribution curves is sufficient in validating the approach and proposed a strategy for dealing with exceptional cases where the sameness test fails.

  • a survival analysis based simulation model for russian wheat aphid population dynamics
    2008
    Co-Authors: Edward J Bechinski
    Abstract:

    Abstract A simulation model for Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), populations is built by integrating survival-analysis-based development and survivor functions and the same-shape Reproduction distribution model in the framework of Leslie [Leslie, P.H., 1945. On the use of matrices in certain population mathematics. Biometrika 33, 183–212] matrix structure. Survival analysis is utilized to model both the development and survival of RWA populations, and the Cox (1972) proportional hazards model is fitted with the data sets from our laboratory observation of 1800 RWA individuals under 25 factorial combinations of five temperature regimes and five barley plant-growth stages. Rather than using simple age-specific survivor rates as in the traditional Leslie matrix, the survivor functions based on survival analysis describe age-specific, temperature and plant stage-dependent RWA survival probabilities. Similarly, a probability model from survival analysis to estimate the probability that an individual will reach mature adult stage is utilized to describe the development process; this makes the transition from nymphal stage to mature adult stage dependent on RWA age as well as temperature and plant-growth stage. Inspired by the same-shape distribution and rate-summation approach for modeling Insect development, a similar approach for modeling Insect Reproduction under variable temperature is developed. This new same-shape Reproduction distribution model incorporates individual variation in Reproduction capability, as well as the effects of RWA age, temperature and plant-growth stage. Consequently, the same-shape Reproduction distribution model replaces the simple age-specific fecundities in Leslie matrix model. To the best of our knowledge, this work is the first to introduce survival analysis to simulation modeling in entomology and ecology and also the first to integrate our newly developed same-shape Reproduction distribution model into application.

Elisabeth Marchal - One of the best experts on this subject based on the ideXlab platform.

  • methoprene tolerant met knockdown in the adult female cockroach diploptera punctata completely inhibits ovarian development
    2014
    Co-Authors: Elisabeth Marchal, Ekaterina F Hult, Juan Huang, Zhenguo Pang, Barbara Stay, Stephen S Tobe
    Abstract:

    Independent of the design of the life cycle of any Insect, their growth and Reproduction are highly choreographed through the action of two versatile hormones: ecdysteroids and juvenile hormones (JH). However, the means by which JH can target tissues and exert its pleiotropic physiological effects is currently still not completely elucidated. Although the identity of the one JH receptor is currently still elusive, recent evidence seems to point to the product of the Methoprene-tolerant gene (Met) as the most likely contender in transducing the action of JH. Studies on the role of this transcription factor have mostly been focused on immature Insect stages. In this study we used the viviparous cockroach Diploptera punctata, a favorite model in studying JH endocrinology, to examine the role of Met during Reproduction. A tissue distribution and developmental profile of transcript levels was determined for Met and its downstream partners during the first gonadotropic cycle of this cockroach. Using RNA interference, our study shows that silencing Met results in an arrest of basal oocyte development; vitellogenin is no longer transcribed in the fat body and no longer taken up by the ovary. Patency is not induced in these animals which fail to produce the characteristic profile of JH biosynthesis typical of the first gonadotropic cycle. Moreover, the ultrastructure of the follicle cells showed conspicuous whorls of rough endoplasmic reticulum and a failure to form chorion. Our study describes the role of Met on a cellular and physiological level during Insect Reproduction, and confirms the role of Met as a key factor in the JH signaling pathway.

Alexander S Raikhel - One of the best experts on this subject based on the ideXlab platform.

  • regulatory pathways controlling female Insect Reproduction
    2018
    Co-Authors: Sourav Roy, Tusar T Saha, Zhen Zou, Alexander S Raikhel
    Abstract:

    The synthesis of vitellogenin and its uptake by maturing oocytes during egg maturation are essential for successful female Reproduction. These events are regulated by the juvenile hormones and ecdysteroids and by the nutritional signaling pathway regulated by neuropeptides. Juvenile hormones act as gonadotropins, regulating vitellogenesis in most Insects, but ecdysteroids control this process in Diptera and some Hymenoptera and Lepidoptera. The complex crosstalk between the juvenile hormones, ecdysteroids, and nutritional signaling pathways differs distinctly depending on the reproductive strategies adopted by various Insects. Molecular studies within the past decade have revealed much about the relationships among, and the role of, these pathways with respect to regulation of Insect Reproduction. Here, we review the role of juvenile hormones, ecdysteroids, and nutritional signaling, along with that of microRNAs, in regulating female Insect Reproduction at the molecular level.

  • Nutritional control of Insect Reproduction
    2015
    Co-Authors: Vlastimil Smykal, Alexander S Raikhel
    Abstract:

    The amino acid-Target of Rapamycin (AA/TOR) and insulin pathways play a pivotal role in Reproduction of female Insects, serving as regulatory checkpoints that guarantee the sufficiency of nutrients for developing eggs. Being evolutionary older, the AA/TOR pathway functions as an initial nutritional sensor that not only activates nutritional responses in a tissue-specific manner, but is also involved in the control of Insect insulin-like peptides (ILPs) secretion. Insulin and AA/TOR pathways also assert their nutritionally linked influence on reproductive events by contributing to the control of biosynthesis and secretion of juvenile hormone and ecdysone. This review covers the present status of our understanding of the contributions of AA/TOR and insulin pathways in Insect Reproduction.