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Li K, Liu K, Wang X, Ma M, Luo X, Chen W, Chen A, Peng Z, Zhang D. Role of nuclear receptors NlHR3 and NlFTZ-F1 in regulating molting and reproduction in Nilaparvata lugens (stål). Front Physiol 2023; 14:1123583. [PMID: 37008006 PMCID: PMC10050704 DOI: 10.3389/fphys.2023.1123583] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/23/2023] [Indexed: 03/17/2023] Open
Abstract
The nuclear receptors HR3 and FTZ-F1 are highly conserved and function to regulate molting and reproduction in both hemimetabolous and holometabolous insects. However, their roles in Nilaparvata lugens are largely unknown. In the present study, we discover that NlHR3 and NlFTZ-F1 are activated in the nymph stages by ecdysone signaling. Transcription disruption of NlHR3 and NlFTZ-F1 expression prevents nymph ecdysis and metamorphosis, which leads to abnormal appearance, malformed ovaries, and lethal phenotypes. In addition, we demonstrate that NlHR3 and NlFTZ-F1 regulate molting and reproduction by interacting with the intrinsic 20E and JH signaling pathways. Our work offers a deep insight into the action mechanisms of HR3 and FTZ-F1 in insects. Moreover, NlHR3 and NlFTZ-F1 could properly be exploited as potential target genes for developing RNAi-based pesticides to control N. lugens.
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Affiliation(s)
- Kailong Li
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
| | - Kanghong Liu
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
| | - Xing Wang
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
| | - Mingyong Ma
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
| | - Xiangwen Luo
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
| | - Wuying Chen
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
| | - Ang Chen
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
| | - Zhaopu Peng
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
| | - Deyong Zhang
- Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China
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Establishment of an immortalized cell line derived from the pupal ovary of Mythimna separata (Lepidoptera: Noctuidae) and identification of the cell source. Cell Tissue Res 2021; 386:661-677. [PMID: 34599689 DOI: 10.1007/s00441-021-03528-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/15/2021] [Indexed: 10/20/2022]
Abstract
Determining the source of primary cells is conductive to enriching sufficient cells with immortal potential thereby improving the success rate of establishing cell lines. However, most of the existing insect cell lines are established by mixing and fragmentation of explants. At present, the origin of cell lines can only be determined according to the cultured tissues, so it is impossible to determine which cell types they come from. In this study, a new cell line designated IOZCAS-Myse-1 was generated from pupal ovaries of the migratory pest Mythimna separata by explant tissues to derive adherent cultures. This paper mainly shows the further descriptive information on the origin of primary cells in the process of ovarian tissue isolation and culture. Phospho-histone H3 antibody-labeled cells with mitotic activity showed that the rapidly developing somatic cells in vivo gradually stopped proliferation when cultured ex vivo. The primary cells dissociated outside the tissue originated from the lumen cells, rather than the germ cells or the follicular epithelium cells. The results suggest that the newly established cell line IOZCAS-Myse-1 had two possible sources. One is the mutation of lumen cells in the vitellarium, and the other is the stem cells with differentiation potential in the germarium of the ovarioles. Moreover, the newly established cell line is sensitive to the infection of Autographa californica multiple nucleopolyhedrovirus, responds to 20-hydroxyecdysone and has weak encapsulation ability. Therefore, the new cell line can be a useful platform for replication of viral insecticides, screening of hormone-based insecticides and immunology research.
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Xu Y, Yang X, Sun X, Li X, Liu Z, Yin Q, Ma L, Zhou D, Sun Y, Shen B, Zhu C. Transcription factor FTZ-F1 regulates mosquito cuticular protein CPLCG5 conferring resistance to pyrethroids in Culex pipiens pallens. Parasit Vectors 2020; 13:514. [PMID: 33054862 PMCID: PMC7559895 DOI: 10.1186/s13071-020-04383-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/28/2020] [Indexed: 12/25/2022] Open
Abstract
Background Culex pipiens pallens poses a serious threat to human health because of its widespread distribution, high carrier capacity for several arboviruses, frequent human-biting, and growth in urban environments. Pyrethroid insecticides have been mainly used to control adult Cx. pipiens pallens during outbreaks of mosquito-borne diseases. Unfortunately, mosquitoes have developed resistance, rendering the insecticides ineffective. Cuticular resistance is the primary mechanism of pyrethroid resistance. Previously, we revealed that cuticular protein of low complexity CPLCG5 is a major cuticular protein associated with deltamethrin resistance in Cx. pipiens pallens, which is enriched in the cuticle of mosquitoes’ legs and participates in pyrethroid resistance by forming a rigid matrix. However, the regulatory mechanisms of its transcription remain unknown. Results First, qRT-PCR analysis revealed that the expression of FTZ-F1 (encoding Fushi tarazu-Factor 1) was ~ 1.8-fold higher in the deltamethrin-resistant (DR) than deltamethrin-susceptible (DS) strains at 24 h post-eclosion (PE) and ~ 2.2-fold higher in the DR strain than in the DS strain at 48 h PE. CPLCG5 and FTZ-F1 were co-expressed in the legs, indicating that they might play an essential role in the legs. Dual luciferase reporter assays and EMSA (electrophoretic mobility shift experiments) revealed that FTZ-F1 regulates the transcription of CPLCG5 by binding to the FTZ-F1 response element (− 870/− 864). Lastly, knockdown of FTZ-F1 not only affected CPLCG5 expression but also altered the cuticle thickness and structure of the legs, increasing the susceptibility of the mosquitoes to deltamethrin in vivo. Conclusions The results revealed that FTZ-F1 regulates the expression of CPLCG5 by binding to the CPLCG5 promoter region, altering cuticle thickness and structure, and increasing the susceptibility of mosquitoes to deltamethrin in vivo. This study revealed part of the mechanism of cuticular resistance, providing a deeper understanding of insecticide resistance.![]()
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Affiliation(s)
- Yang Xu
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Xiaoshan Yang
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Xiaohong Sun
- Department of Blood Transfusion, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xixi Li
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Zhihan Liu
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Qi Yin
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Lei Ma
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Dan Zhou
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Yan Sun
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China.
| | - Bo Shen
- Department of Pathogen Biology, Nanjing Medical University, Nanjing, China.
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Qian HY, Zhang X, Zhao GD, Guo HM, Li G, Xu AY. Effects of Pyriproxyfen Exposure on Reproduction and Gene Expressions in Silkworm, Bombyx mori. INSECTS 2020; 11:insects11080467. [PMID: 32722009 PMCID: PMC7469178 DOI: 10.3390/insects11080467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/19/2020] [Accepted: 07/22/2020] [Indexed: 11/16/2022]
Abstract
The silkworm, Bombyx mori Linnaeus, is an important economic insect and a representative model organism of Lepidoptera, which has been widely used in the study of reproduction and development. The development of the silkworm's reproductive gland is easily affected by many external factors, such as chemical insecticides. After the silkworm larvae were treated with different concentrations of pyriproxyfen, the results showed that the number of eggs and hatching rate of eggs in the silkworm can be reduced by pyriproxyfen, and the concentration effects were displayed. Pyriproxyfen exposure could affect the normal development of the ovary tissue by reducing the number of oocytes and oogonia in the ovaries of silkworm fed with pyriproxyfen. We employed qRT-PCR, to detect the expressions of genes related to ovary development (Vg, Ovo, Otu, Sxl-S and Sxl-L) and hormone regulation (EcR and JHBP2) in silkworm. Our study showed that the transcription levels of Vg, Ovo, Otu, Sxl-S and Sxl-L in the treatment group were lower than those in the control group (6.08%, 61.99%, 83.51%, 99.31% and 71.95%, respectively). The transcription level of ECR was 70.22% for the control group, while that of JHBP2 was upregulated by 3.92-fold. Changes of transcription levels of these genes caused by pyriproxyfen exposure ultimately affect the absorption of nutrients, energy metabolism, ovary development and egg formation of the silkworm, thus leading to reproductive disorders of the silkworm. In general, our study revealed the response of silkworm reproduction to pyriproxyfen exposure and provided a certain reference value for the metabolism of the silkworm to pyriproxyfen.
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Affiliation(s)
- He-Ying Qian
- School of Biotechnology, Jiangsu University of Science and Technology, Jiangsu 212018, China; (X.Z.); (G.-D.Z.); (H.-M.G.); (G.L.)
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Jiangsu 212018, China
- Correspondence: (H.-Y.Q.); (A.-Y.X.)
| | - Xiao Zhang
- School of Biotechnology, Jiangsu University of Science and Technology, Jiangsu 212018, China; (X.Z.); (G.-D.Z.); (H.-M.G.); (G.L.)
| | - Guo-Dong Zhao
- School of Biotechnology, Jiangsu University of Science and Technology, Jiangsu 212018, China; (X.Z.); (G.-D.Z.); (H.-M.G.); (G.L.)
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Jiangsu 212018, China
| | - Hui-Min Guo
- School of Biotechnology, Jiangsu University of Science and Technology, Jiangsu 212018, China; (X.Z.); (G.-D.Z.); (H.-M.G.); (G.L.)
| | - Gang Li
- School of Biotechnology, Jiangsu University of Science and Technology, Jiangsu 212018, China; (X.Z.); (G.-D.Z.); (H.-M.G.); (G.L.)
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Jiangsu 212018, China
| | - An-Ying Xu
- School of Biotechnology, Jiangsu University of Science and Technology, Jiangsu 212018, China; (X.Z.); (G.-D.Z.); (H.-M.G.); (G.L.)
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Jiangsu 212018, China
- Correspondence: (H.-Y.Q.); (A.-Y.X.)
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Cheng X, Li F, Chen J, Wang H, Mao T, Li J, Hu J, Li B. Mechanism of trace acetamiprid-caused reproductive disorders in silkworm, Bombyx mori. PEST MANAGEMENT SCIENCE 2019; 75:2672-2681. [PMID: 30740867 DOI: 10.1002/ps.5373] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 01/24/2019] [Accepted: 02/04/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Neonicotinoid insecticides are widely used in the prevention and control of pests in agriculture and forestry, but they can also affect the development of nontarget economic insects. In order to determine the effects of trace acetamiprid on the development of reproductive system of silkworm, we studied the gonad development and endogenous hormone metabolism in silkworms exposed to trace acetamiprid. RESULT The silkworm showed mild poisoning symptoms after being exposed to trace acetamiprid (0.01 mg L-1 ). After 96 h of acetamiprid exposure, the body weight of silkworm was decreased by 7.67% and the ovary and fallopian tube were abnormally developed. The egg production in adults was decreased by 197 ± 29, and the egg weight was decreased by 0.52 ± 0.01 mg. Quantitative RT-PCR analysis showed that the relative expression levels of ovarian development-related genes Vg, Ovo, Otu, Sxl-S and Sxl-L were downregulated by 0.71, 0.77, 0.47, 0.67 and 0.88-fold, respectively. The transcriptional expression of ecdysone metabolism-related gene (EcR) in the ovary was downregulated by 0.46-fold while the expression of juvenile hormone-related gene (JHBP2) was upregulated by 1.36-fold. In hemolymph of acetamiprid exposed larvae, the content of ecdysone was reduced whereas the content of juvenile hormone was increased. CONCLUSION Trace acetamiprid may cause reproductive dysfunction in silkworms through regulating the metabolism of endogenous hormones. Our study provides a reference for elucidating the mechanism of acetamiprid-induced reproductive disorders in insects. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Xiaoyu Cheng
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, China
| | - Fanchi Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, China
| | - Jian Chen
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, China
| | - Hui Wang
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, China
| | - Tingting Mao
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, China
| | - Jinxin Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, China
| | - Jiahuan Hu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, China
| | - Bing Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, China
- School of Basic Medicine and Biological Sciences, Soochow University, Sericulture Institute of Soochow University, Suzhou, China
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Suang S, Manaboon M, Singtripop T, Hiruma K, Kaneko Y, Tiansawat P, Neumann P, Chantawannakul P. Larval diapause termination in the bamboo borer, Omphisa fuscidentalis. PLoS One 2017; 12:e0174919. [PMID: 28369111 PMCID: PMC5378396 DOI: 10.1371/journal.pone.0174919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 03/17/2017] [Indexed: 11/18/2022] Open
Abstract
In insects, juvenile hormone (JH) and 20-hydroxyecdysone (20E) regulate larval growth and molting. However, little is known about how this cooperative control is terminating larval diapause especially in the bamboo borer, Omphisa fuscidentalis. In both in vivo and in vitro experiments, we here measured the expression levels of genes which were affected by juvenile hormone analogue (JHA: S-methoprene) and 20-hydroxyecdysone (20E) in diapausing O. fuscidentalis larvae. Corresponding mRNA expression changes in the subesophageal ganglion (SG) and prothoracic gland (PG) were evaluated using qRT-PCR. The data showed similar response patterns of JH receptor gene (OfMet), diapause hormone gene (OfDH-PBAN), ecdysone receptor genes (OfEcR-A and OfEcR-B1) and ecdysone inducible genes (OfBr-C, OfE75A, OfE75B, OfE75C and OfHR3). JHA induced the expressions of OfMet and OfDH-PBAN in both SG and PG, whereas ecdysone receptor genes and ecdysone inducible genes were induced by JHA only in PG. For 20E treatment group, expressions of ecdysone receptor genes and ecdysone inducible genes in both SG and PG were increased by 20E injection. In addition, the in vitro experiments showed that OfMet and OfDH-PBAN were up-regulated by JHA alone, but ecdysone receptor genes and ecdysone inducible genes were up-regulated by JHA and 20E. However, OfMet and OfDH-PBAN in the SG was expressed faster than OfMet and OfDH-PBAN in the PG and the expression of ecdysone receptor genes and ecdysone inducible genes induced by JHA was much later than observed for 20E. These results indicate that JHA might stimulate the PG indirectly via factors (OfMet and OfDH-PBAN) in the SG, which might be a regulatory mechanism for larval diapause termination in O. fuscidentalis.
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Affiliation(s)
- Suphawan Suang
- Endocrinology Research Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Manaporn Manaboon
- Endocrinology Research Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Tippawan Singtripop
- Endocrinology Research Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Kiyoshi Hiruma
- Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki, Japan
| | - Yu Kaneko
- Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki, Japan
| | - Pimonrat Tiansawat
- Bee Protection Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Peter Neumann
- Bee Protection Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Agroscope, Swiss Bee Research Centre, Bern, Switzerland
| | - Panuwan Chantawannakul
- Endocrinology Research Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Bee Protection Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
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Guo WC, Liu XP, Fu KY, Shi JF, Lü FG, Li GQ. Functions of nuclear receptor HR3 during larval-pupal molting in Leptinotarsa decemlineata (Say) revealed by in vivo RNA interference. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 63:23-33. [PMID: 26005119 DOI: 10.1016/j.ibmb.2015.05.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 05/12/2015] [Accepted: 05/16/2015] [Indexed: 06/04/2023]
Abstract
Our previous results revealed that RNA interference-aided knockdown of Leptinotarsa decemlineata FTZ-F1 (LdFTZ-F1) reduced 20E titer, and impaired pupation. In this study, we characterized a putative LdHR3 gene, an early-late 20E-response gene upstream of LdFTZ-F1. Within the first, second and third larval instars, three expression peaks of LdHR3 occurred just before the molt. In the fourth (final) larval instar 80 h after ecdysis and prepupal stage 3 days after burying into soil, two LdHR3 peaks occurred. The LdHR3 expression peaks coincide with the peaks of circulating 20E level. In vitro midgut culture and in vivo bioassay revealed that 20E and an ecdysteroid agonist halofenozide (Hal) enhanced LdHR3 expression in the final larval instars. Conversely, a decrease in 20E by feeding a double-stranded RNA (dsRNA) against an ecdysteroidogenesis gene Ldshd repressed the expression. Moreover, Hal rescued the transcript levels in the Ldshd-silenced larvae. Thus, 20E peaks activate the expression of LdHR3. Furthermore, ingesting dsRNA against LdHR3 successfully knocked down the target gene, and impaired pupation. Finally, knockdown of LdHR3 upregulated the transcription of three ecdysteroidogenesis genes (Ldphm, Lddib and Ldshd), increased 20E titer, and activated the expression of two 20E-response genes (LdEcR and LdFTZ-F1). Thus, LdHR3 functions in regulation of pupation in the Colorado potato beetle.
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Affiliation(s)
- Wen-Chao Guo
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China.
| | - Xin-Ping Liu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Kai-Yun Fu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Ji-Feng Shi
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Feng-Gong Lü
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
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8
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Tsatsarounos SP, Rodakis GC, Lecanidou R. Analysis of developmentally regulated chorion gene promoter architecture via electroporation of silk moth follicles. INSECT MOLECULAR BIOLOGY 2015; 24:71-81. [PMID: 25256090 DOI: 10.1111/imb.12136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the silk moth Bombyx mori, chorion genes of the same developmental specificity are organized in divergently transcribed α/β gene pairs, sharing a common 5' flanking promoter region. This bidirectional promoter contains a complete set of cis-elements responsible for developmentally accurate gene expression. In the present paper, based on the observation that Bombyx chorion gene promoters contain cis-elements for the same transcription factors without concrete evidence on which of them are essential, we address the question as to how promoter architecture (number, orientation and position of common factor binding sites) facilitates developmentally accurate chorion gene regulation. To this end, we constructed several mutated promoter regions of an early-middle gene pair and cloned them upstream of a reporter gene to introduce these plasmid constructs into silk moth follicle epithelial cells via electroporation as an efficient and quick method for transient expression. This is the first time that an ex vivo method had been applied to test the impact of systematic cis-element mutations on a chorion gene promoter. Our results confirmed the importance of the HMGA factor and the role of the GATA factor as an early repressor, and led to a more detailed understanding of which C/EBP sites participate in the regulation of early-middle chorion gene expression.
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Affiliation(s)
- S P Tsatsarounos
- Department of Biochemistry and Molecular Biology, Faculty of Biology, National and Kapodistrian, University of Athens, Athens, Greece
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Wang JL, Li SL, Qin YY, Chen ZJ. Analysis of progesterone receptor membrane component 1 mutation in Han Chinese women with premature ovarian failure. Reprod Biomed Online 2014; 29:640-3. [PMID: 25246111 DOI: 10.1016/j.rbmo.2014.08.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 06/28/2014] [Accepted: 08/05/2014] [Indexed: 02/01/2023]
Abstract
The gene PGRMC1 is highly expressed in the granulose and luteal cells of rodent and primate ovaries. Its role in anti-apoptosis and regulating cell-cycle progression suggests a role in regulating follicle growth. The hypothesis is supported by the study in mice and studies in Sweden. In this study, the coding exons of PGRMC1 were sequenced among 196 Chinese women with premature ovarian failure (POF) and 200 controls, and one novel missense mutation was identified (C.556C>T, p. Pro186Ser) in the POF group and one novel SNP (C.533C>T, p. Trh177Ile) was identified in both groups. The mutation is not considered causative because protein prediction did not indicate a deleterious effect. It is concluded that coding mutations of PGRMC1 do not seem to be a common cause of the disease in Han Chinese women. Future studies in larger cohorts from other ethnic groups are necessary to establish the role of PGRMC1 in POF.
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Affiliation(s)
- Jiu-Ling Wang
- Qilu Hospital of Shandong University, Jinan 250012, China
| | - Shu-Ling Li
- Qilu Hospital of Shandong University, Jinan 250012, China
| | - Ying-Ying Qin
- Center for Reproductive Medicine, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China
| | - Zi-Jiang Chen
- Center for Reproductive Medicine, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China.
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Gao P, Chen AL, Zhao QL, Shen XJ, Qiu ZY, Xia DG, Tang SM, Zhang GZ. Differentially expressed genes in the ovary of the sixth day of pupal "Ming" lethal egg mutant of silkworm, Bombyx mori. Gene 2013; 527:161-6. [PMID: 23769927 DOI: 10.1016/j.gene.2013.05.049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 05/10/2013] [Accepted: 05/23/2013] [Indexed: 10/26/2022]
Abstract
The "Ming" lethal egg mutant (l-em) is a vitelline membrane mutant in silkworm, Bombyx mori. The eggs laid by the l-em mutant lose water, ultimately causing death within an hour. Previous studies have shown that the deletion of BmEP80 is responsible for the l-em mutation in silkworm, B. mori. In the current study, digital gene expression (DGE) was performed to investigate the difference of gene expression in ovaries between wild type and l-em mutant on the sixth day of the pupal stage to obtain a global view of gene expression profiles using the ovaries of three l-em mutants and three wild types. The results showed a total of 3,463,495 and 3,607,936 clean tags in the wild type and the l-em mutant libraries, respectively. Compared with those of wild type, 239 differentially expressed genes were detected in the l-em mutant, wherein 181 genes are up-regulated and 58 genes are down-regulated in the mutant strain. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis results showed that no pathway was significantly enriched and three pathways are tightly related to protein synthesis among the five leading pathways. Moreover, the expression profiles of eight important differentially expressed genes related to oogenesis changed. These results provide a comprehensive gene expression analysis of oogenesis and vitellogenesis in B. mori which facilitates understanding of both the specific molecular mechanism of the 1-em mutant and Lepidopteran oogenesis in general.
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Affiliation(s)
- Peng Gao
- Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003, China
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Tian L, Ma L, Guo E, Deng X, Ma S, Xia Q, Cao Y, Li S. 20-Hydroxyecdysone upregulates Atg genes to induce autophagy in the Bombyx fat body. Autophagy 2013; 9:1172-87. [PMID: 23674061 DOI: 10.4161/auto.24731] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Autophagy is finely regulated at multiple levels and plays crucial roles in development and disease. In the fat body of the silkworm, Bombyx mori, autophagy occurs and Atg gene expression peaks during the nonfeeding molting and pupation stages when the steroid hormone (20-hydroxyecdysone; 20E) is high. Injection of 20E into the feeding larvae upregulated Atg genes and reduced TORC1 activity resulting in autophagy induction in the fat body. Conversely, RNAi knockdown of the 20E receptor partner (USP) or targeted overexpression of a dominant negative mutant of the 20E receptor (EcR (DN) ) in the larval fat body reduced autophagy and downregulated the Atg genes, confirming the importance of 20E-induction of Atg gene expression during pupation. Moreover, in vitro treatments of the larval fat body with 20E upregulated the Atg genes. Five Atg genes were potentially 20E primary-responsive, and a 20E response element was identified in the Atg1 (ortholog of human ULK1) promoter region. Furthermore, RNAi knockdown of 4 key genes (namely Br-C, E74, HR3 and βftz-F1) in the 20E-triggered transcriptional cascade reduced autophagy and downregulated Atg genes to different levels. Taken together, we conclude that in addition to blocking TORC1 activity for autophagosome initiation, 20E upregulates Atg genes to induce autophagy in the Bombyx fat body.
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Affiliation(s)
- Ling Tian
- Key Laboratory of Insect Developmental and Evolutionary Biology; Institute of Plant Physiology and Ecology; Shanghai Institutes for Biological Sciences; Chinese Academy of Sciences; Shanghai, China; State Key Laboratory of Silkworm Genome Biology; Southwest University; Chongqing, China
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12
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Carter JM, Baker SC, Pink R, Carter DRF, Collins A, Tomlin J, Gibbs M, Breuker CJ. Unscrambling butterfly oogenesis. BMC Genomics 2013; 14:283. [PMID: 23622113 PMCID: PMC3654919 DOI: 10.1186/1471-2164-14-283] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 04/05/2013] [Indexed: 12/16/2022] Open
Abstract
Background Butterflies are popular model organisms to study physiological mechanisms
underlying variability in oogenesis and egg provisioning in response to
environmental conditions. Nothing is known, however, about; the
developmental mechanisms governing butterfly oogenesis, how polarity in the
oocyte is established, or which particular maternal effect genes regulate
early embryogenesis. To gain insights into these developmental mechanisms
and to identify the conserved and divergent aspects of butterfly oogenesis,
we analysed a de novo ovarian transcriptome of the Speckled Wood
butterfly Pararge aegeria (L.), and compared the results with known
model organisms such as Drosophila melanogaster and Bombyx
mori. Results A total of 17306 contigs were annotated, with 30% possibly novel or highly
divergent sequences observed. Pararge aegeria females expressed
74.5% of the genes that are known to be essential for D.
melanogaster oogenesis. We discuss the genes involved in all
aspects of oogenesis, including vitellogenesis and choriogenesis, plus those
implicated in hormonal control of oogenesis and transgenerational hormonal
effects in great detail. Compared to other insects, a number of significant
differences were observed in; the genes involved in stem cell maintenance
and differentiation in the germarium, establishment of oocyte polarity, and
in several aspects of maternal regulation of zygotic development. Conclusions This study provides valuable resources to investigate a number of divergent
aspects of butterfly oogenesis requiring further research. In order to fully
unscramble butterfly oogenesis, we also now also have the resources to
investigate expression patterns of oogenesis genes under a range of
environmental conditions, and to establish their function.
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Affiliation(s)
- Jean-Michel Carter
- Evolutionary Developmental Biology Research Group, Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford, OX3 0BP, UK
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13
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Lin Y, Meng Y, Wang YX, Luo J, Katsuma S, Yang CW, Banno Y, Kusakabe T, Shimada T, Xia QY. Vitellogenin receptor mutation leads to the oogenesis mutant phenotype "scanty vitellin" of the silkworm, Bombyx mori. J Biol Chem 2013; 288:13345-55. [PMID: 23515308 PMCID: PMC3650373 DOI: 10.1074/jbc.m113.462556] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In insects, the vitellogenin receptor (VgR) mediates the uptake of vitellogenin (Vg) from the hemolymph by developing oocytes. The oogenesis mutant scanty vitellin (vit) of Bombyx mori (Bm) lacks vitellin and 30-kDa proteins, but B. mori egg-specific protein and BmVg are normal. The vit eggs are white and smaller compared with the pale yellow eggs of the wild type and are embryonic lethal. This study found that a mutation in the B. mori VgR gene (BmVgR) is responsible for the vit phenotype. We cloned the cDNA sequences encoding WT and vit BmVgR. The functional domains of BmVgR are similar to those of other low-density lipoprotein receptors. When compared with the wild type, a 235-bp genomic sequence in vit BmVgR is substituted for a 7-bp sequence. This mutation has resulted in a 50-amino acid deletion in the third Class B region of the first epidermal growth factor (EGF1) domain. BmVgR is expressed specifically in oocytes, and the transcriptional level is changed dramatically and consistently with maturation of oocytes during the previtellogenic periods. Linkage analysis confirmed that BmVgR is mutated in the vit mutant. The coimmunoprecipitation assay confirmed that mutated BmVgR is able to bind BmVg but that BmVg cannot be dissociated under acidic conditions. The WT phenotype determined by RNA interference was similar to that of the vit phenotype for nutritional deficiency, such as BmVg and 30-kDa proteins. These results showed that BmVgR has an important role in transporting proteins for egg formation and embryonic development in B. mori.
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Affiliation(s)
- Ying Lin
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
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14
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Sdralia N, Swevers L, Iatrou K. BmVMP90, a large vitelline membrane protein of the domesticated silkmoth Bombyx mori, is an essential component of the developing ovarian follicle. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:717-727. [PMID: 22801025 DOI: 10.1016/j.ibmb.2012.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 06/21/2012] [Accepted: 06/23/2012] [Indexed: 06/01/2023]
Abstract
We present the characterization of BmVMP90, a vitelline membrane protein (VMP) of the silkmoth Bombyx mori bearing similarities with dipteran VMPs whose existence had recently been suggested by an in silico analysis of the silkmoth genome and follicular cell RNA expression analyses. Using a specific antibody, we determine the presence of BmVMP90 protein in ovarian follicular cell extracts at the end of vitellogenesis and in vitelline membrane extracts but not in the chorion of fractionated eggshells isolated from ovulated follicles. Whole mount follicle immunofluorescence studies reveal a pattern of BmVMP90 deposition matching the «imprinted» pattern of follicular cells on the vitelline membrane surface. Antisense DNA-directed inhibition BmVMP90 expression in ex vivo cultures of early vitellogenic follicles produced a phenotype of kidney- or bean-shaped follicles with detached follicular epithelia, suggestive of the importance of BmVMP90 for the integrity of developing follicles and normal deposition of the chorion structure that follows vitelline membrane formation but no adverse effects on the execution of the follicular cell-imprinted program of choriogenesis per se.
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Affiliation(s)
- Nadia Sdralia
- Insect Molecular Genetics and Biotechnology Group, Institute of Biosciences and Applications, National Centre for Scientific Research Demokritos, Aghia Paraskevi Attikis, Athens, Greece
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15
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Roy A, Shimizu S, Kiya T, Mita K, Iwami M. Identification of 20-hydroxyecdysone-inducible genes from larval brain of the silkworm, Bombyx mori, and their expression analysis. Zoolog Sci 2012; 29:333-9. [PMID: 22559968 DOI: 10.2108/zsj.29.333] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The insect brain secretes prothoracicotropic hormone (PTTH), which stimulates the prothoracic gland to synthesize ecdysone. The active metabolite of ecdysone, 20-hydroxyecdysone (20E), works through ecdysone receptor (EcR) and ultraspiracle (USP) to initiate molting and metamorphosis by regulating downstream genes. Previously, we found that EcR was expressed in the PTTH-producing neurosecretory cells (PTPCs) in larval brain of the silkworm Bombyx mori, suggesting that PTPCs function as the master cells of development under the regulation of 20E. To gain a better understanding of the molecular mechanism of the 20E control of PTPCs, we performed a comprehensive screening of genes induced by 20E using DNA microarray with brains of day-2 fifth instar silkworm larvae. Forty-one genes showed greater than twofold changes caused by artificial application of 20E. A subsequent semiquantitative screening identified ten genes upregulated by 20E, four of which were novel or not previously identified as 20E-response genes. Developmental profiling determined that two genes, UP4 and UP5, were correlated with the endogenous ecdysteroid titer. Whole-mount in situ hybridization showed exclusive expression of these two genes in two pairs of cells in the larval brain in response to 20E-induction, suggesting that the cells are PTPCs. BLAST searches revealed that UP4 and UP5 are Bombyx homologs of vrille and tarsal-less, respectively. The present study identifies 20E-induced genes that may be involved in the ecdysone signal hierarchies underlying pupal-adult development and/or the 20E regulation of PTPCs.
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Affiliation(s)
- Anuradha Roy
- Division of Life Sciences, Graduate school of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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16
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Swevers L, Liu J, Huvenne H, Smagghe G. Search for limiting factors in the RNAi pathway in silkmoth tissues and the Bm5 cell line: the RNA-binding proteins R2D2 and Translin. PLoS One 2011; 6:e20250. [PMID: 21637842 PMCID: PMC3102679 DOI: 10.1371/journal.pone.0020250] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 04/28/2011] [Indexed: 11/30/2022] Open
Abstract
RNA interference (RNAi), an RNA-dependent gene silencing process that is initiated by double-stranded RNA (dsRNA) molecules, has been applied with variable success in lepidopteran insects, in contrast to the high efficiency achieved in the coleopteran Tribolium castaneum. To gain insight into the factors that determine the efficiency of RNAi, a survey was carried out to check the expression of factors that constitute the machinery of the small interfering RNA (siRNA) and microRNA (miRNA) pathways in different tissues and stages of the silkmoth, Bombyx mori. It was found that the dsRNA-binding protein R2D2, an essential component in the siRNA pathway in Drosophila, was expressed at minimal levels in silkmoth tissues. The silkmoth-derived Bm5 cell line was also deficient in expression of mRNA encoding full-length BmTranslin, an RNA-binding factor that has been shown to stimulate the efficiency of RNAi. However, despite the lack of expression of the RNA-binding proteins, silencing of a luciferase reporter gene was observed by co-transfection of luc dsRNA using a lipophilic reagent. In contrast, gene silencing was not detected when the cells were soaked in culture medium supplemented with dsRNA. The introduction of an expression construct for Tribolium R2D2 (TcR2D2) did not influence the potency of luc dsRNA to silence the luciferase reporter. Immunostaining experiments further showed that both TcR2D2 and BmTranslin accumulated at defined locations within the cytoplasm of transfected cells. Our results offer a first evaluation of the expression of the RNAi machinery in silkmoth tissues and Bm5 cells and provide evidence for a functional RNAi response to intracellular dsRNA in the absence of R2D2 and Translin. The failure of TcR2D2 to stimulate the intracellular RNAi pathway in Bombyx cells is discussed.
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Affiliation(s)
- Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biology, National Centre for Scientific Research “Demokritos,” Athens, Greece
- * E-mail: (LS); (GS)
| | - Jisheng Liu
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Hanneke Huvenne
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Guy Smagghe
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- * E-mail: (LS); (GS)
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17
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Wang Y, Kaftanoglu O, Siegel AJ, Page RE, Amdam GV. Surgically increased ovarian mass in the honey bee confirms link between reproductive physiology and worker behavior. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:1816-1824. [PMID: 20688074 DOI: 10.1016/j.jinsphys.2010.07.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 07/24/2010] [Accepted: 07/26/2010] [Indexed: 05/29/2023]
Abstract
Honey bee (Apis mellifera L.) workers are essentially sterile females that are used to study how complex social behavior develops. Workers perform nest tasks, like nursing larvae, prior to field tasks, like foraging. Despite worker sterility, this behavioral progression correlates with ovary size: workers with larger ovaries (many ovary filaments) start foraging at younger ages on average. It is untested, however, whether the correlation confers a causal relationship between ovary size and behavioral development. Here, we successfully grafted supernumerary ovaries into worker bees to produce an artificial increase in the amount of ovary tissue. We next measured fat body mRNA levels for the yolk precursor gene vitellogenin, which influences honey bee behavioral development and can correlate with ovary size. Vitellogenin was equally expressed in surgical controls and bees with supernumerary ovaries, leading us to predict that these groups would be characterized by equal behavior. Contrary to our prediction, bees with supernumerary ovaries showed accelerated behavioral development compared to surgical controls, which behaved like reference bees that were not treated surgically. To explore this result we monitored fat body expression levels of a putative ecdysteroid-response gene, HR46, which is genetically linked to ovary size in workers. Our data establish that social insect worker behavior can be directly influenced by ovaries, and that HR46 expression changes with ovary size independent of vitellogenin.
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Affiliation(s)
- Ying Wang
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA.
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18
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Mosallanejad H, Badisco L, Swevers L, Soin T, Knapen D, Vanden Broeck J, Smagghe G. Ecdysone signaling and transcript signature in Drosophila cells resistant against methoxyfenozide. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:1973-1985. [PMID: 20816975 DOI: 10.1016/j.jinsphys.2010.08.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 08/26/2010] [Accepted: 08/26/2010] [Indexed: 05/29/2023]
Abstract
Methoxyfenozide (RH-2485) is a non-steroidal ecdysteroid agonist with a dibenzoylhydrazine structure, representing a group used as novel biorational insecticides in the control of insect pests. Here we report on the selection of Drosophila melanogaster S2 cells for resistance to inhibition of cell proliferation by methoxyfenozide by ∼ 1000-fold over 4 months. Cells were exposed to gradually increasing concentrations of methoxyfenozide and selected out based on the ecdysteroid-sensitive response for cell proliferation. In the resistant cells, the ecdysteroid receptor (EcR/USP) complex was no longer active in the presence of methoxyfenozide. But when resistant cells were relaxed from pressure in methoxyfenozide-free medium, induction of the reporter construct was observed. In parallel, EcR/USP functionality was also restored when resistant cells were rescued by a Drosophila EcR plasmid. However, it was striking that in the resistant cells the ecdysteroid-sensitive response for cell proliferation was not restored upon methoxyfenozide withdrawal, indicating permanent changes in the physiology of the cells during selection. To investigate changes in gene expression caused by inactivation of the EcR/USP complex in resistant cells, Drosophila oligo 14kv1 microarrays were used and probed with cDNAs from resistant cells in the presence and absence of ecdysone agonist on one hand and from unselected sensitive cells on the other hand. A selection of 324 differentially expressed genes was assigned covering diverse functions as transport, enzyme activity, cytoskeleton organization, cell cycle machinery, transcription/translation and ecdysteroid signaling. Besides the identification of (primary and secondary) target genes of the EcR/USP signaling pathway, this analysis also allows to gain insights into the mechanism of resistance and on the crosstalk between ecdysteroid signaling and cell proliferation-linked processes.
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Affiliation(s)
- Hadi Mosallanejad
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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19
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Tsitoura P, Andronopoulou E, Tsikou D, Agalou A, Papakonstantinou MP, Kotzia GA, Labropoulou V, Swevers L, Georgoussi Z, Iatrou K. Expression and membrane topology of Anopheles gambiae odorant receptors in lepidopteran insect cells. PLoS One 2010; 5:e15428. [PMID: 21082026 PMCID: PMC2972716 DOI: 10.1371/journal.pone.0015428] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 09/21/2010] [Indexed: 12/21/2022] Open
Abstract
A lepidopteran insect cell-based expression system has been employed to express three Anopheles gambiae odorant receptors (ORs), OR1 and OR2, which respond to components of human sweat, and OR7, the ortholog of Drosophila's OR83b, the heteromerization partner of all functional ORs in that system. With the aid of epitope tagging and specific antibodies, efficient expression of all ORs was demonstrated and intrinsic properties of the proteins were revealed. Moreover, analysis of the orientation of OR1 and OR2 on the cellular plasma membrane through the use of a novel ‘topology screen’ assay and FACS analysis demonstrates that, as was recently reported for the ORs in Drosophila melanogaster, mosquito ORs also have a topology different than their mammalian counterparts with their N-terminal ends located in the cytoplasm and their C-terminal ends facing outside the cell. These results set the stage for the production of mosquito ORs in quantities that should permit their detailed biochemical and structural characterization and the exploration of their functional properties.
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Affiliation(s)
- Panagiota Tsitoura
- Insect Molecular Genetics and Biotechnology Group, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Evi Andronopoulou
- Insect Molecular Genetics and Biotechnology Group, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Daniela Tsikou
- Insect Molecular Genetics and Biotechnology Group, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Adamantia Agalou
- Laboratory of Cellular Signaling and Molecular Pharmacology, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Maria P. Papakonstantinou
- Laboratory of Cellular Signaling and Molecular Pharmacology, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Georgia A. Kotzia
- Insect Molecular Genetics and Biotechnology Group, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Vassiliki Labropoulou
- Insect Molecular Genetics and Biotechnology Group, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology Group, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Zafiroula Georgoussi
- Laboratory of Cellular Signaling and Molecular Pharmacology, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Kostas Iatrou
- Insect Molecular Genetics and Biotechnology Group, Institute of Biology, National Centre for Scientific Research “Demokritos”, Athens, Greece
- * E-mail:
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20
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Hannas BR, Wang YH, Baldwin WS, Li Y, Wallace AD, LeBlanc GA. Interactions of the crustacean nuclear receptors HR3 and E75 in the regulation of gene transcription. Gen Comp Endocrinol 2010; 167:268-78. [PMID: 20346363 PMCID: PMC2873136 DOI: 10.1016/j.ygcen.2010.03.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 02/18/2010] [Accepted: 03/20/2010] [Indexed: 01/17/2023]
Abstract
Endocrine signal transduction occurs through cascades that involve the action of both ligand-dependent and ligand-independent nuclear receptors. In insects, two such nuclear receptors are HR3 and E75 that interact to transduce signals initiated by ecdysteroids. We have cloned these nuclear receptors from the crustacean Daphnia pulex to assess their function as regulators of gene transcription in this ecologically and economically important group of organisms. Both nuclear receptors from D. pulex (DappuHR3 (group NR1F) and DappuE75 (group NR1D)) exhibit a high degree of sequence similarity to other NR1F and NR1D group members that is indicative of monomeric binding to the RORE (retinoid orphan receptor element). DappuE75 possesses key amino acid residues required for heme binding to the ligand-binding domain. Next, we developed a gene transcription reporter assay containing a luciferase reporter gene driven by the RORE. DappuHR3, but not DappuE75, activated transcription of the luciferase gene in this system. Co-transfection experiments revealed that DappuE75 suppressed DappuHR3-dependent luciferase transcription in a dose-dependent manner. Electrophoretic mobility shift assays confirmed that DappuHR3 bound to the RORE. However, we found no evidence that DappuE75 similarly bound to the response element. These experiments further demonstrated that DappuE75 prevented DappuHR3 from binding to the response element. In conclusion, DappuHR3 functions as a transcriptional activator of genes regulated by the RORE and DappuE75 is a negative regulator of this activity. DappuE75 does not suppress the action of DappuHR3 by occupying the response element but presumably interacts directly with the DappuHR3 protein. Taken together with the previous demonstration that daphnid HR3 is highly induced by 20-hydroxyecdysone, these results support the premise that HR3 is a major component of ecdysteroid signaling in some crustaceans and is under the negative regulatory control of E75.
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Affiliation(s)
- Bethany R. Hannas
- Department of Environmental & Molecular Toxicology, North Carolina State University, Raleigh, NC, 27695
| | - Ying H. Wang
- Department of Environmental & Molecular Toxicology, North Carolina State University, Raleigh, NC, 27695
| | | | - Yangchun Li
- Environmental Toxicology, Clemson University, Clemson, SC, 29634
| | - Andrew D. Wallace
- Department of Environmental & Molecular Toxicology, North Carolina State University, Raleigh, NC, 27695
| | - Gerald A. LeBlanc
- Department of Environmental & Molecular Toxicology, North Carolina State University, Raleigh, NC, 27695
- Corresponding author: Box 7633, Raleigh, NC, USA 27695-7633 Phone: (919) 515-7404 Fax: (919) 515-7169
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21
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Cai Y, Yu X, Zhou Q, Yu C, Hu H, Liu J, Lin H, Yang J, Zhang B, Cui P, Hu S, Yu J. Novel microRNAs in silkworm (Bombyx mori). Funct Integr Genomics 2010; 10:405-15. [DOI: 10.1007/s10142-010-0162-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 01/18/2010] [Accepted: 01/31/2010] [Indexed: 11/30/2022]
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22
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Swevers L, Soin T, Mosallanejad H, Iatrou K, Smagghe G. Ecdysteroid signaling in ecdysteroid-resistant cell lines from the polyphagous noctuid pest Spodoptera exigua. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2008; 38:825-833. [PMID: 18675909 DOI: 10.1016/j.ibmb.2008.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 06/04/2008] [Accepted: 06/17/2008] [Indexed: 05/26/2023]
Abstract
Although dibenzoylhydrazine-type non-steroidal ecdysone agonists such as methoxyfenozide (RH-2485) have an excellent performance record, the emergence of resistance could severely compromise the efficacy of these compounds in integrated pest management programs. To investigate possible mechanisms of resistance, cell lines derived from the polyphagous noctuid pest Spodoptera exigua (Se4 cells) were selected for continuous growth in the presence of high concentrations of 20-hydroxyecdysone (20E) or methoxyfenozide. Here we describe an analysis of ecdysteroid receptor signaling in the ecdysteroid-resistant Se4 cell lines. In contrast to other ecdysteroid-resistant cell lines described in literature, our data support the existence of a normal functioning ecdysteroid receptor complex in the resistant Se4 cell lines: (1) using a recombinant BmNPV baculovirus as a transduction tool, activation of an ecdysone-responsive luciferase cassette was demonstrated; (2) the early gene HR3 is constitutively expressed in the resistant cell lines that are grown in the presence of 20E or methoxyfenozide. Quantitative RT-PCR experiments indicated that expression levels of SeEcR mRNA were comparable among sensitive and resistant cell lines. Sequencing of PCR fragments also revealed the presence of SeEcR mRNA with a wild-type ligand-binding domain in resistant cells. Finally, a possible role for the gene FTZ-F1, whose expression correlates with the absence of circulating ecdysteroids during insect development, in the resistance mechanism was investigated. However, it was observed that FTZ-F1, in contrast to what is observed during insect development, is constitutively expressed in Se4 cells and that its expression is not regulated by the addition of ecdysteroid. It is proposed that the resistance mechanism in Se4 cells resides at the coupling between the conserved hierarchical cascade of early and early-late gene expression and the differentiation program in the Se4 cell line. The use of insect cell lines for the investigation of resistance against dibenzoylhydrazine ecdysone agonists and their relevance for uncovering resistance mechanisms in insects during pest control programs is discussed.
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Affiliation(s)
- Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biology, National Centre for Scientific Research "Demokritos", Aghia Paraskevi Attikis, Athens, Greece
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23
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Siaussat D, Bozzolan F, Porcheron P, Debernard S. The 20-hydroxyecdysone-induced signalling pathway in G2/M arrest of Plodia interpunctella imaginal wing cells. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2008; 38:529-539. [PMID: 18405831 DOI: 10.1016/j.ibmb.2008.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 01/10/2008] [Accepted: 01/11/2008] [Indexed: 05/26/2023]
Abstract
The mechanisms involved in the control of cellular proliferation by the steroid hormone 20-hydroxyecdysone (20E) in insects are not known. We dissected the 20E signalling pathway responsible for G2/M arrest of imaginal cells from the IAL-PID2 cells of the Indian meal moth Plodia interpunctella. We first used a 5'-3' RACE-based strategy to clone a 4479bp cDNA encoding a putative P. interpunctella HR3 transcription factor named PiHR3. The deduced amino acid sequence of PiHR3 was highly similar to those of HR3 proteins from other lepidopterans, e.g. Manduca sexta and Bombyx mori. Using double-stranded RNA-mediated interference (dsRNAi), we then succeeded in blocking the ability of 20E to induce the expression of PiEcR-B1, PiUSP-2 and PiHR3 genes that encode the P. interpunctella ecdysone receptor B1-isoform, Ultraspiracle-2 isoform, the insect homologue of the vertebrate retinoid X receptor, and the HR3 transcription factor. We showed that inhibiting the 20E induction of PiEcR-B1, PiUSP-2 and PiHR3 mRNAs prevented the decreased expression of B cyclin and consequently the G2/M arrest of IAL-PID2 cells. Using this functional approach, we revealed the participation of EcR, USP and HR3 in a 20E signalling pathway that controls the proliferation of imaginal cells by regulating the expression of B cyclin.
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Affiliation(s)
- David Siaussat
- UMR 1272A Physiologie de l'Insecte, Signalisation et Communication, Université Pierre et Marie Curie, 7 quai Saint Bernard, 75005 Paris, France
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24
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Cruz J, Martín D, Bellés X. Redundant ecdysis regulatory functions of three nuclear receptor HR3 isoforms in the direct-developing insect Blattella germanica. Mech Dev 2006; 124:180-9. [PMID: 17258436 DOI: 10.1016/j.mod.2006.12.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Revised: 12/13/2006] [Accepted: 12/14/2006] [Indexed: 11/29/2022]
Abstract
In hemimetabolous insects, the molecular basis of the 20-hydroxyecdysone (20E)-triggered genetic hierarchy is practically unknown. In the cockroach Blattella germanica, we had previously characterized one isoform of the ecdysone receptor, BgEcR-A, and two isoforms of its heterodimeric partner, BgRXR-S and BgRXR-L. One of the early-late genes of the 20E-triggered genetic hierarchy, is HR3. In the present paper, we report the discovery of three isoforms of HR3 in B. germanica, that were named BgHR3-A, BgHR3-B(1) and BgHR3-B(2). Expression studies in prothoracic gland, epidermis and fat body indicate that the expression of the three isoforms coincides with the peak of circulating ecdysteroids at each nymphal instar. Experiments in vitro with fat body tissue have shown that 20E induces the expression of BgHR3 isoforms, and that incubation with 20E and the protein inhibitor cycloheximide does not inhibit the induction, which indicates that the effect of 20E on BgHR3 activation is direct. This has been further confirmed by RNAi in vivo of BgEcR-A, which has shown that this nuclear receptor is required to fully activate the expression of BgHR3. RNAi has been also used to demonstrate the functions of BgHR3 in ecdysis. Nymphs with silenced BgHR3 completed the apolysis but were unable to ecdyse (they had duplicated and superimposed the mouth parts, the hypopharinge, the tracheal system and the cuticle layers). This indicates that BgHR3 is directly involved in ecdysis. Finally, RNAi of specific isoforms has showed that they are functionally redundant, at least regarding the ecdysis process.
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Affiliation(s)
- Josefa Cruz
- Department of Molecular Biodiversity, Institut de Biologia Molecular de Barcelona (CSIC), Jordi Girona 18, 08034 Barcelona, Spain
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Ogura T, Minakuchi C, Nakagawa Y, Smagghe G, Miyagawa H. Molecular cloning, expression analysis and functional confirmation of ecdysone receptor and ultraspiracle from the Colorado potato beetle Leptinotarsa decemlineata. FEBS J 2005; 272:4114-28. [PMID: 16098194 DOI: 10.1111/j.1742-4658.2005.04823.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
cDNA cloning of ecdysone receptor (EcR) and ultraspiracle (USP) of the coleopteran Colorado potato beetle Leptinotarsa decemlineata (LdEcR and LdUSP) was conducted. Amino-acid sequences of the proteins deduced from cDNA sequences showed striking homology to those of other insects, especially the coleopteran yellow mealworm Tenebrio molitor. Northern hybridization analysis showed a 12.4-kb message for the LdEcR A-isoform, a 10.5-kb message for the LdEcR B1-isoform and a 5.7-kb message for the LdUSP, in fat body, gut, integument, testis and ovaries. In developmental profile studies, expression of both the LdEcR and LdUSP transcript in integument changed dramatically. In gel mobility shift assays, in vitro translated LdEcR alone bound weakly to the pal1 ecdysone response element, although LdUSP alone did not, and this binding was dramatically enhanced by the addition of LdUSP. LdEcR/LdUSP complex also showed significant binding to an ecdysone agonist, ponasterone A (K(D) = 2.8 nm), while LdEcR alone showed only weak binding (K(D) = 73.4 nm), and LdUSP alone did not show any binding. The receptor-binding affinity of various ecdysone agonists to LdEcR/LdUSP was not correlated to their larvicidal activity to L. decemlineata. From these results, it was suggested that multiple factors including the receptor binding affinity are related to the determination of the larvicidal activity of nonsteroidal ecdysone agonists in L. decemlineata.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Cloning, Molecular
- Coleoptera
- DNA, Complementary
- Electrophoresis, Polyacrylamide Gel
- Ligands
- Molecular Sequence Data
- Protein Binding
- Protein Biosynthesis
- RNA, Messenger/genetics
- Receptors, Steroid/agonists
- Receptors, Steroid/chemistry
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Sequence Homology, Amino Acid
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Affiliation(s)
- Takehiko Ogura
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan
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Hiruma K, Riddiford LM. Differential control of MHR3 promoter activity by isoforms of the ecdysone receptor and inhibitory effects of E75A and MHR3. Dev Biol 2004; 272:510-21. [PMID: 15282165 DOI: 10.1016/j.ydbio.2004.04.028] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Revised: 04/22/2004] [Accepted: 04/26/2004] [Indexed: 11/17/2022]
Abstract
MHR3 is an ecdysone-inducible transcription factor whose expression in both Manduca sexta epidermis and the Manduca GV1 cell line is induced by 20-hydroxyecdysone (20E) in vitro. There are four putative ecdysone response elements (EcRE) in the 2.6-kb flanking region of the MHR3 promoter. The most proximal, EcRE1, is necessary for activation of the promoter by 20E in the GV1 cells because the mutation of EcRE1 caused the loss of responsiveness to 20E. Previous studies showed that EcR-B1/USP-1 bound only to EcRE1 and high levels of this complex increased the 20E-induced activation, whereas the presence of high USP-2 prevented this increased activation. When we expressed EcR-A alone or in combination with USP-1 under the control of Autographa californica baculovirus promoter (pIE1hr), the activation of the 2.6-kb promoter by 20E was reduced by about 50%. Moreover, when EcR-A was expressed together with both EcR-B1 and USP-1, it reduced the normal activation caused by EcR-B1 and USP-1 by 50%. Gel mobility shift assays showed no binding of EcR-A/USP-1 to EcRE1. The presence of EcR-A, however, reduced the binding of EcR-B1/USP-1 by about 50%. These findings suggest that EcR-A competes with EcR-B1 for binding of USP-1, leading to a decline in activity of the promoter. In addition, E75A, another ecdysone-induced transcription factor, and MHR3 itself suppressed MHR3 promoter activity by binding to the monomeric response element (MRE2). Therefore, MHR3 can be down-regulated both by itself and by E75A.
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Affiliation(s)
- Kiyoshi Hiruma
- Department of Biology, University of Washington, Seattle, WA 98195-1800, USA
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27
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Swevers L, Iatrou K. The ecdysone regulatory cascade and ovarian development in lepidopteran insects: insights from the silkmoth paradigm. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2003; 33:1285-1297. [PMID: 14599500 DOI: 10.1016/j.ibmb.2003.06.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The developing ovariole of the silkmoth Bombyx mori represents an excellent model for studies on the changes that occur in gene expression during the execution of long-term developmental programs. All stages of follicle development, which differ from each other by 2-2.5 h of developmental time, are organized in a single array and can be isolated simultaneously for physiological, biochemical and gene expression studies from a single animal. Recently, significant progress has been made toward the understanding of the hormonal regulation and autonomous implementation of the developmental program that governs follicular cell differentiation during oogenesis in Bombyx. In this review, the developmental career of the ovarian follicle during pharate adult development is discussed in view of the new physiological, biochemical and gene expression data that have recently accumulated. An overview is presented of the changes in expression of structural and regulatory genes and their hormonal regulation in the developing follicle during the transitions among the broad developmental periods of previtellogenesis, vitellogenesis and choriogenesis. Ovarian development in silkmoth pharate adults is induced by 20-hydroxy-ecdysone (20E) through the activation of a regulatory cascade similar to the one observed during Drosophila development. The transition from previtellogenesis to vitellogenesis corresponds to a late response to the hormone and is characterized by the induction of the expression of a unique isoform of the nuclear receptor BmHR3 and the follicular cell-specific yolk protein ESP. The transition from early to middle and late vitellogenesis and choriogenesis, on the other hand, is regulated by positively and negatively acting intra- and extra-ovarian factors. In vitro cultures of developing ovarioles reveal the requirement for the presence of an as yet unidentified growth factor(s) in the hemolymph, while the follicle developmental arrest that is observed after treatment with the ecdysone agonist tebufenozide indicates the requirement for a decline in the level of 20E. The initiation of choriogenesis is characterized by the transcriptional activation of the gene BmGATAbeta that encodes GATA transcription factors, and the chorion genes in the follicular cells. Furthermore, modulation of the activity of BmGATAbeta at the posttranscriptional level is crucial for the stage-specific activation of chorion genes during late choriogenesis. The developing ovariole of the silkmoth is, therefore, emerging as an important model for the study of insect oogenesis and the action of the steroid hormone 20E at the molecular level.
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Affiliation(s)
- Luc Swevers
- Institute of Biology, National Centre for Scientific Research "Demokritos", Aghia Paraskevi Attikis, 153 10 Athens, Greece.
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28
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Swevers L, Kravariti L, Ciolfi S, Xenou-Kokoletsi M, Ragoussis N, Smagghe G, Nakagawa Y, Mazomenos B, Iatrou K. A cell‐based high‐throughput screening system for detecting ecdysteroid agonists and antagonists in plant extracts and libraries of synthetic compounds. FASEB J 2003; 18:134-6. [PMID: 14630695 DOI: 10.1096/fj.03-0627fje] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Screening systems for ecdysteroid mimetic or antiecdysteroid substances in plant extracts or libraries of synthetic compounds are commonly based on the observation of morphological and/or growth responses in insect cell lines. Because these responses are slow and require careful monitoring, existing screening systems are considered limited regarding their applicability to analysis in high-throughput (HT) formats. Here we describe the generation of transformed silkmoth (Bombyx mori) cell lines that respond to the addition of ecdysone-like substances through the expression of the green fluorescent protein (GFP) and the appearance of green fluorescence. Because tests consist of three simple steps, i.e., 1) distribution of transformed cells in microtiter plates; 2) addition of compounds/extracts at different concentrations; and 3) quantification of fluorescence intensity by a fluorescence plate reader, they can be performed quickly and be easily adapted to a HT format. The generated reporter cell lines are used for the screening of extracts from available plant collections for the presence of compounds with ecdysone mimetic or antagonistic activities as well as for monitoring subsequent activity during enrichment and purification steps. The same cell lines are also used here for the determination of structure-activity relationships among available synthetic dibenzoylhydrazine derivatives. Finally, for the identified agonists, we show that their activity as determined by the cell-based screening assays parallels their bioactivity in growth inhibition and toxicity assays carried out on live insects.
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Affiliation(s)
- Luc Swevers
- Institute of Biology, National Centre for Scientific Research Demokritos, P.O. Box 60228, Aghia Paraskevi Attikis, 153 10 Athens, Greece.
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29
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Swevers L, Eystathioy T, Iatrou K. The orphan nuclear receptors BmE75A and BmE75C of the silkmoth Bombyx mori: hornmonal control and ovarian expression. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2002; 32:1643-1652. [PMID: 12429116 DOI: 10.1016/s0965-1748(02)00104-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The steroid hormone 20-hydroxyecdysone (20E) plays a key role in the stimulation of ovarian follicle development in the silkmoth, Bombyx mori. To understand better the mechanism by which 20E regulates silkmoth oogenesis, Bombyx homologs of the ecdysone-inducible orphan nuclear receptor E75 (BmE75) were cloned and their expression was analyzed in developing ovaries and staged follicles during metamorphosis. Of the two BmE75 isoforms isolated, only the A-isoform (BmE75A) has been identified previously in lepidopteran insects. BmE75C, on the other hand, shows significant sequence homology in its N-terminus to the Drosophila E75C isoform. Northern blot analysis shows unique expression patterns for each isoform mRNA during ovarian development. While the A-isoform seems to be mainly implicated in the earlier stages of the ecdysone response during previtellogenesis and vitellogenesis, expression of the C-isoform becomes strongly induced in an ecdysteroid-independent fashion at the transition from vitellogenesis to choriogenesis. Our data indicate a complex regulation of the expression of the BmE75 gene during oogenesis and postulate a new role for the BmE75C receptor at the end of vitellogenesis and the beginning of choriogenesis.
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Affiliation(s)
- L Swevers
- Institute of Biology, National Centre for Scientific Research Demokritos, P.O. Box 60228, Aghia Paraskevi Attikis, 153 10 Athens, Greece
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30
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Swevers L, Ito K, Iatrou K. The BmE75 nuclear receptors function as dominant repressors of the nuclear receptor BmHR3A. J Biol Chem 2002; 277:41637-44. [PMID: 12200421 DOI: 10.1074/jbc.m203581200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The orphan nuclear receptors BmE75 and BmHR3 are induced by 20-hydroxyecdysone in the ovary of the silk moth Bombyx mori at the beginning of pupation and show stage-specific expression in ovarian follicles during pharate adult development. To analyze the function of these receptors, we have developed a transactivation assay based on the transcriptional stimulation of a retinoic acid receptor-related receptor response element (RORE)-linked promoter-reporter construct. Co-transfection of a Bombyx cell line with a BmHR3A expression construct results in constitutive activation of the reporter, whereas expression of BmE75 has no measurable effects on reporter expression. However, when the BmE75 receptors are co-introduced with BmHR3A into the cells, the BmHR3A-mediated transactivation is repressed. Repression of BmHR3A by BmE75 occurs by two distinct mechanisms. Increasing doses of BmE75 efficiently displace BmHR3A bound to the RORE target site in gel retardation assays, indicating that both receptors compete for common DNA target sites. However, analysis of the function of deletion mutants of BmE75 in the transactivation assay indicates that repression can also occur in the absence of the DNA-binding domain and that the C-terminal F domain is sufficient for repression. In gel retardation assays, the two receptor types form a ternary complex on a single RORE, suggesting that repression is also mediated by protein interactions on the DNA target site. Yeast two-hybrid assays show that BmHR3A interacts with BmE75 and that this interaction is dependent on the C terminus of BmHR3A and the F domain of BmE75. Because the C terminus of BmHR3A contains a strong activation domain, we predict that BmE75 blocks activation by BmHR3A through competition for co-activator binding sites located at the C terminus of BmHR3A. Our data also indicate that the transcriptional activities of BmHR3A and BmE75 are integrated in such a way that activation of RORE-linked target genes depends on the relative expression levels of the two receptor types.
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Affiliation(s)
- Luc Swevers
- Institute of Biology, National Centre for Scientific Research Demokritos, P. O. Box 60228, Aghia Paraskevi Attikis, 153 10 Athens, Greece
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31
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Kendirgi F, Swevers L, Iatrou K. An ovarian follicular epithelium protein of the silkworm (Bombyx mori) that associates with the vitelline membrane and contributes to the structural integrity of the follicle. FEBS Lett 2002; 524:59-68. [PMID: 12135742 DOI: 10.1016/s0014-5793(02)03003-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have cloned and functionally characterized a novel protein, BmVMP30, which is synthesized by the cells of the follicular epithelium of the ovarian follicles of the domesticated silkworm Bombyx mori, secreted from them and associated with the vitelline membrane. BmVMP30 is a 30 kDa protein that bears limited structural features reminiscent of other insect vitelline membrane proteins. Although BmVMP30 does not share pronounced similarities or signature motifs with other reported proteins, its temporal and spatial expression and its behavior throughout oogenesis suggest that it is a novel member of the insect vitelline membrane protein family. The protein is expressed exclusively in the cells of the follicular epithelium during stages -15 to -1 of vitellogenesis, secreted from them and, ultimately, localized at the junction between the oocyte and the eggshell, where the vitelline membrane is located. Treatment of follicles with an antisense oligonucleotide that encompasses the translation initiation codon results in the production of an N-terminally truncated protein and disruption of the integrity of the follicular epithelium. Antisense oligonucleotide treatment, however, has no effect on the implementation of the developmental program that directs the autonomous progression of ovarian follicles through the last stages of vitellogenesis and choriogenesis.
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Affiliation(s)
- Frederic Kendirgi
- Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
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