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Abstract
Juvenile hormone (JH) is critical for multiple aspects of insect development and physiology. Although roles for the hormone have received considerable study, an understanding of the molecules necessary for JH action in insects has been frustratingly slow to evolve. Methoprene-tolerant (Met) in Drosophila melanogaster fulfills many of the requirements for a hormone receptor gene. A paralogous gene, germ-cell expressed (gce), possesses homology and is a candidate as a Met partner in JH action. Expression of gce was found to occur at multiple times and in multiple tissues during development, similar to that previously found for Met. To probe roles of this gene in JH action, we carried out in vivo gce over- and underexpression studies. We show by overexpression studies that gce can substitute in vivo for Met, alleviating preadult but not adult phenotypic characters. We also demonstrate that RNA interference-driven knockdown of gce expression in transgenic flies results in preadult lethality in the absence of MET. These results show that (1) unlike Met, gce is a vital gene and shows functional flexibility and (2) both gene products appear to promote JH action in preadult but not adult development.
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Yang Q, Gong ZJ, Zhou Y, Yuan JQ, Cheng J, Tian L, Li S, Lin XD, Xu R, Zhu ZR, Mao C. Role of Drosophila alkaline ceramidase (Dacer) in Drosophila development and longevity. Cell Mol Life Sci 2010; 67:1477-90. [PMID: 20112046 PMCID: PMC11115685 DOI: 10.1007/s00018-010-0260-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 12/31/2009] [Accepted: 01/06/2010] [Indexed: 10/19/2022]
Abstract
Ceramidases catalyze the hydrolysis of ceramides to generate sphingosine (SPH) and fatty acids, and ceramide metabolism is implicated in various biological responses in Drosophila melanogaster. Here we report the cloning, biochemical characterization, and functional analysis of a Drosophila alkaline ceramidase (Dacer). Dacer, a membrane-bound protein of 284 amino acids, shares homology with yeast and mammalian alkaline ceramidases. Overexpression of Dacer in High Five insect cells increases ceramidase activity in the alkaline pH range, indicating that Dacer is a bona fide alkaline ceramidase. Dacer mRNA is highly expressed in the midgut and at the pupal stage. An inactivation of Dacer by insertional mutagenesis increases the levels of ceramides in both Drosophila pupae and adult flies. Dacer inactivation increases Drosophila pre-adult development time, lifespan, and anti-oxidative stress capacity. Collectively, these results suggest that Dacer plays an important role in the Drosophila development and longevity by controlling the metabolism of ceramides.
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Affiliation(s)
- Qiong Yang
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, the Ministry of Agriculture of China, Hangzhou, Zhejiang, 310029 China
- The Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang, 310029 China
- Present Address: Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, 210014 China
| | - Zhong-Jun Gong
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, the Ministry of Agriculture of China, Hangzhou, Zhejiang, 310029 China
- The Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang, 310029 China
| | - Ying Zhou
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, the Ministry of Agriculture of China, Hangzhou, Zhejiang, 310029 China
- The Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang, 310029 China
| | - Jing-Qun Yuan
- Center for Chemical Analysis and Detection, Zhejiang University, Hangzhou, Zhejiang, 310029 China
| | - Jiaan Cheng
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, the Ministry of Agriculture of China, Hangzhou, Zhejiang, 310029 China
- The Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang, 310029 China
| | - Lin Tian
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032 China
| | - Sheng Li
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032 China
| | - Xin-Da Lin
- College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang, 310018 China
| | - Ruijuan Xu
- Department of Medicine and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425 USA
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425 USA
| | - Zeng-Rong Zhu
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, the Ministry of Agriculture of China, Hangzhou, Zhejiang, 310029 China
- The Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang, 310029 China
| | - Cungui Mao
- Department of Medicine and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425 USA
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425 USA
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Wang S, Liu S, Liu H, Wang J, Zhou S, Jiang RJ, Bendena WG, Li S. 20-hydroxyecdysone Reduces Insect Food Consumption Resulting in Fat Body Lipolysis During Molting and Pupation. J Mol Cell Biol 2010; 2:128-38. [DOI: 10.1093/jmcb/mjq006] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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104
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Riddiford LM, Truman JW, Mirth CK, Shen YC. A role for juvenile hormone in the prepupal development of Drosophila melanogaster. Development 2010; 137:1117-26. [PMID: 20181742 DOI: 10.1242/dev.037218] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To elucidate the role of juvenile hormone (JH) in metamorphosis of Drosophila melanogaster, the corpora allata cells, which produce JH, were killed using the cell death gene grim. These allatectomized (CAX) larvae were smaller at pupariation and died at head eversion. They showed premature ecdysone receptor B1 (EcR-B1) in the photoreceptors and in the optic lobe, downregulation of proliferation in the optic lobe, and separation of R7 from R8 in the medulla during the prepupal period. All of these effects of allatectomy were reversed by feeding third instar larvae on a diet containing the JH mimic (JHM) pyriproxifen or by application of JH III or JHM at the onset of wandering. Eye and optic lobe development in the Methoprene-tolerant (Met)-null mutant mimicked that of CAX prepupae, but the mutant formed viable adults, which had marked abnormalities in the organization of their optic lobe neuropils. Feeding Met(27) larvae on the JHM diet did not rescue the premature EcR-B1 expression or the downregulation of proliferation but did partially rescue the premature separation of R7, suggesting that other pathways besides Met might be involved in mediating the response to JH. Selective expression of Met RNAi in the photoreceptors caused their premature expression of EcR-B1 and the separation of R7 and R8, but driving Met RNAi in lamina neurons led only to the precocious appearance of EcR-B1 in the lamina. Thus, the lack of JH and its receptor Met causes a heterochronic shift in the development of the visual system that is likely to result from some cells 'misinterpreting' the ecdysteroid peaks that drive metamorphosis.
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Affiliation(s)
- Lynn M Riddiford
- Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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