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A native sericin wound dressing spun directly from silkworms enhances wound healing. Colloids Surf B Biointerfaces 2023; 225:113228. [PMID: 36889105 DOI: 10.1016/j.colsurfb.2023.113228] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/11/2023] [Accepted: 02/25/2023] [Indexed: 03/02/2023]
Abstract
It is attractive and challenging to develop a bioactive dressing based on native nondestructive sericin. Here, a native sericin wound dressing was secreted directly by silkworms bred through regulating their spinning behaviors. To be excited, our first reported wound dressing possesses original unique features of natural sericin, including natural structures and bioactivities. Besides, it has a porous fibrous network structure with a porosity of 75 %, thus achieving excellent air permeability. Moreover, the wound dressing exhibits pH-responsive degradability, softness, and super absorbency properties whose equilibrium water contents are no less than 75 % in various pH conditions. Furthermore, the sericin wound dressing demonstrates high mechanical strength, reaching 2.5 MPa tensile strength. Importantly, we confirmed good cell compatibility of sericin wound dressing that can support cell viability, proliferation, and migration for a long time. When tested in a mouse full-thickness skin wound model, the wound dressing efficiently accelerated the healing process. Our findings suggest that the sericin wound dressing has promising application and commercial value in wound repair.
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Dias ACA, Rodrigues MMS, Silva AA. Effect of acute and chronic exposure to ammonia on different larval instars of Anopheles darlingi (Diptera: Culicidae). JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2019; 44:112-118. [PMID: 31124231 DOI: 10.1111/jvec.12335] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/11/2019] [Indexed: 06/09/2023]
Abstract
Anopheles darlingi (Diptera: Culicidae) is the most important vector of malaria in South America and has already been found in peri-urban areas that commonly contain toxic nitrogenous compounds, such as ammonia. The adaptation of mosquitoes to polluted breeding sites can increase their distribution and affect the dynamics of vector-borne diseases such as malaria. Therefore, the present study investigated the tolerance of larval instars of An. darlingi to ammonia under acute and chronic exposure conditions. Anopheles darlingi larval mortality, development time, and pupal and adult production using larvae of the 1st (L1) and 3rd (L3) instar were assessed as both acute and chronic effects of exposure to different concentrations of ammonia. Lethal concentrations (LCs) for L1 larvae were lower than LCs for L3 larvae. In general, higher ammonia concentrations caused an increase in larval mortality, especially in chronically exposed L1 larvae. The larval development time in L1 and L3 was longer with chronic treatment and decreased with increasing concentrations of ammonia. The number of pupae was very low for acutely exposed L1 and L3 larvae. Likewise, the probability of adult production decreased with increasing ammonia concentrations. This is the first report on the tolerance of An. darlingi to pollutants.
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Affiliation(s)
- Alyne C A Dias
- Programa de Pós-Graduação em Biologia Experimental.Universidade Federal de Rondônia, Porto Velho, RO, Brasil
| | | | - Alexandre A Silva
- Universidade Federal de Rondônia, Laboratório de Bioecologia de Insetos (LaBEIn) L, 76801-059 Porto Velho, RO, Brasil
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Zhu YN, Wang LZ, Li CC, Cui Y, Wang M, Lin YJ, Zhao RP, Wang W, Xiang H. Artificial selection on storage protein 1 possibly contributes to increase of hatchability during silkworm domestication. PLoS Genet 2019; 15:e1007616. [PMID: 30668559 PMCID: PMC6358105 DOI: 10.1371/journal.pgen.1007616] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 02/01/2019] [Accepted: 12/16/2018] [Indexed: 11/19/2022] Open
Abstract
Like other domesticates, the efficient utilization of nitrogen resources is also important for the only fully domesticated insect, the silkworm. Deciphering the way in which artificial selection acts on the silkworm genome to improve the utilization of nitrogen resources and to advance human-favored domestication traits, will provide clues from a unique insect model for understanding the general rules of Darwin's evolutionary theory on domestication. Storage proteins (SPs), which belong to a hemocyanin superfamily, basically serve as a source of amino acids and nitrogen during metamorphosis and reproduction in insects. In this study, through blast searching on the silkworm genome and further screening of the artificial selection signature on silkworm SPs, we discovered a candidate domestication gene, i.e., the methionine-rich storage protein 1 (SP1), which is clearly divergent from other storage proteins and exhibits increased expression in the ova of domestic silkworms. Knockout of SP1 via the CRISPR/Cas9 technique resulted in a dramatic decrease in egg hatchability, without obvious impact on egg production, which was similar to the effect in the wild silkworm compared with the domestic type. Larval development and metamorphosis were not affected by SP1 knockout. Comprehensive ova comparative transcriptomes indicated significant higher expression of genes encoding vitellogenin, chorions, and structural components in the extracellular matrix (ECM)-interaction pathway, enzymes in folate biosynthesis, and notably hormone synthesis in the domestic silkworm, compared to both the SP1 mutant and the wild silkworm. Moreover, compared with the wild silkworms, the domestic one also showed generally up-regulated expression of genes enriched in the structural constituent of ribosome and amide, as well as peptide biosynthesis. This study exemplified a novel case in which artificial selection could act directly on nitrogen resource proteins, further affecting egg nutrients and eggshell formation possibly through a hormone signaling mediated regulatory network and the activation of ribosomes, resulting in improved biosynthesis and increased hatchability during domestication. These findings shed new light on both the understanding of artificial selection and silkworm breeding from the perspective of nitrogen and amino acid resources. Like other domesticates, nitrogen resources are also important for the only fully domesticated insect, the silkworm. Deciphering the way in which artificial selection acts on the silkworm genome to improve the utilization of nitrogen resources, thereby advancing human-favored domestication traits, will provide clues from a unique insect model for understanding the general rules of Darwin's theory on artificial selection. However, the mechanisms of domestication in the silkworm remain largely unknown. In this study, we focused on one important nitrogen resource, the storage protein (SP). We discovered that the methionine-rich storage protein 1 (SP1), which is divergent from other SPs, is the only target of artificial selection. Based on functional evidence, together with key findings from the comprehensive comparative transcriptome, we propose that artificial selection favored higher expression of SP1 in the domestic silkworm, which would influence the genes or pathways vital for egg development and eggshell formation. Artificial selection also consistently favored activated ribosome activities and improved amide and peptide biosynthesis in the ova, like what they may act in the silk gland to increase silk-cocoon yield. We highlighted a novel case in which artificial selection could directly act on a nitrogen resource protein associated with a human-desired domestication trait.
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Affiliation(s)
- Ya-Nan Zhu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Li-Zhi Wang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Cen-Cen Li
- College of Life Sciences, Xinyang Normal University, Xinyang, China
| | - Yong Cui
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Man Wang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yong-Jian Lin
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Ruo-Ping Zhao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Wen Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Center for Ecological and Environmental Sciences, Key Laboratory for Space Bioscience & Biotechnology, Northwestern Poly-technical University, Xi’an, China
| | - Hui Xiang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- * E-mail:
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Xiang H, Liu X, Li M, Zhu Y, Wang L, Cui Y, Liu L, Fang G, Qian H, Xu A, Wang W, Zhan S. The evolutionary road from wild moth to domestic silkworm. Nat Ecol Evol 2018; 2:1268-1279. [PMID: 29967484 DOI: 10.1038/s41559-018-0593-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 05/29/2018] [Indexed: 12/22/2022]
Abstract
The Silk Road, which derives its name from the trade of silk produced by the domestic silkworm Bombyx mori, was an important episode in the development and interaction of human civilizations. However, the detailed history behind silkworm domestication remains ambiguous, and little is known about the underlying genetics with respect to important aspects of its domestication. Here, we reconstruct the domestication processes and identify selective sweeps by sequencing 137 representative silkworm strains. The results present an evolutionary scenario in which silkworms may have been initially domesticated in China as trimoulting lines, then subjected to independent spreads along the Silk Road that gave rise to the development of most local strains, and further improved for modern silk production in Japan and China, having descended from diverse ancestral sources. We find that genes with key roles in nitrogen and amino acid metabolism may have contributed to the promotion of silk production, and that circadian-related genes are generally selected for their adaptation. We additionally identify associations between several candidate genes and important breeding traits, thereby advancing the applicable value of our resources.
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Affiliation(s)
- Hui Xiang
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology and School of Life Sciences, South China Normal University, Guangzhou, China.,State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Xiaojing Liu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Muwang Li
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Ya'nan Zhu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Lizhi Wang
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology and School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yong Cui
- Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology and School of Life Sciences, South China Normal University, Guangzhou, China
| | - Liyuan Liu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Gangqi Fang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Heying Qian
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China
| | - Anying Xu
- School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.
| | - Wen Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China. .,Center for Ecological and Environmental Sciences, Northwestern Polytechnical University, Xi'an, China.
| | - Shuai Zhan
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai, China.
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Tunca H, Venard M, Colombel EA, Tabone E. A new substitute host and its effects on some biological properties of Ooencyrtus kuvanae. BULLETIN OF ENTOMOLOGICAL RESEARCH 2017; 107:742-748. [PMID: 28325169 DOI: 10.1017/s0007485317000244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Lymantia dispar (L.) (Lepidoptera: Lymantriidae), commonly known as the gypsy moth, is a serious forest pest, and beneficial insects are particularly important for reducing its population numbers. Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae) is an arrhenotokous, solitary egg parasitoid of L. dispar. In this study, we evaluated a new substitute host, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae) for O. kuvanae. We investigated some of the biological effects of O. kuvanae on P. ricini eggs. In this context, the importance of the age of the female parasitoid (1, 3 or 5 days old), host age (1-2 and 3-4 days old) and host number (40, 60 and 80 host eggs) were examined under laboratory conditions (25 ± 1 °C, 65 ± 5% relative humidity and a 16 : 8 h photoperiod [light : dark]). The highest rate of offspring production (89.90%) occurred with 40 (1-2-day-old) host eggs and 5-day-old females. The mean developmental period ranged from 16.5 ± 0.08 days to 18.7 ± 0.08 days. The mean lifespan of the parasitoid was 51.10 ± 1.1 (n = 60) days with bio-honey and 3.92 ± 0.14 (n = 60) days without food. The mean fecundity was 68.88 ± 3.22 offspring/female. Peak adult emergence occurred between 2 and 9 days. The mean oviposition and mean post-oviposition periods of the female parasitoid were 22.76 ± 1.37 days and 13.64 ± 1.40 days, respectively. O. kuvanae was reared for more than ten generations on the eggs of P. ricini. Based on our findings, P. ricini can be used to rear O. kuvanae for the biological control of L. dispar.
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Affiliation(s)
- Hilal Tunca
- Department of Plant Protection, Faculty of Agriculture, Ankara University, 06110, Ankara Dıskapı, Turkey
| | - Marine Venard
- INRA, UEFM site Villa Thuret, Laboratoire BioContrôle, 90 Chemin Raymond, 06160, Antibes, France
| | - Etty-Ambre Colombel
- INRA, UEFM site Villa Thuret, Laboratoire BioContrôle, 90 Chemin Raymond, 06160, Antibes, France
| | - Elisabeth Tabone
- INRA, UEFM site Villa Thuret, Laboratoire BioContrôle, 90 Chemin Raymond, 06160, Antibes, France
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Zhou L, Li H, Hao F, Li N, Liu X, Wang G, Wang Y, Tang H. Developmental Changes for the Hemolymph Metabolome of Silkworm (Bombyx mori L.). J Proteome Res 2015; 14:2331-47. [PMID: 25825269 DOI: 10.1021/acs.jproteome.5b00159] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Silkworm (Bombyx mori) is a lepidopteran-holometabolic model organism. To understand its developmental biochemistry, we characterized the larval hemolymph metabonome from the third instar to prepupa stage using (1)H NMR spectroscopy whilst hemolymph fatty acid composition using GC-FID/MS. We unambiguously assigned more than 60 metabolites, among which tyrosine-o-β-glucuronide, mesaconate, homocarnosine, and picolinate were reported for the first time from the silkworm hemolymph. Phosphorylcholine was the most abundant metabolite in all developmental stages with exception for the periods before the third and fourth molting. We also found obvious developmental dependence for the hemolymph metabonome involving multiple pathways including protein biosyntheses, glycolysis, TCA cycle, the metabolisms of choline amino acids, fatty acids, purines, and pyrimidines. Most hemolymph amino acids had two elevations during the feeding period of the fourth instar and prepupa stage. Trehalose was the major blood sugar before day 8 of the fifth instar, whereas glucose became the major blood sugar after spinning. C16:0, C18:0 and its unsaturated forms were dominant fatty acids in hemolymph. The developmental changes of hemolymph metabonome were associated with dietary nutrient intakes, biosyntheses of cell membrane, pigments, proteins, and energy metabolism. These findings offered essential biochemistry information in terms of the dynamic metabolic changes during silkworm development.
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Affiliation(s)
- Lihong Zhou
- †College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.,‡Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,¶College of Life Sciences, Jianghan University, Wuhan 430056, China
| | - Huihui Li
- ‡Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Fuhua Hao
- ‡Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Ning Li
- ‡Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Xin Liu
- †College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Guoliang Wang
- ¶College of Life Sciences, Jianghan University, Wuhan 430056, China
| | - Yulan Wang
- ‡Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,⊥Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310058, China
| | - Huiru Tang
- ‡Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,§State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, Metabonomics and Systems Biology Laboratory, School of Life Sciences, Fudan University, Shanghai 200433, China
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LeBlanc A, Arnold AA, Genard B, Nadalini JB, Heine MOS, Marcotte I, Tremblay R, Sleno L. Determination of isotopic labeling of proteins by precursor ion scanning liquid chromatography/tandem mass spectrometry of derivatized amino acids applied to nuclear magnetic resonance studies. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:1165-1174. [PMID: 22499191 DOI: 10.1002/rcm.6204] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
RATIONALE A method has been developed for the quantitation of isotopic labeling of proteins using liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the application of protein nuclear magnetic resonance (NMR) studies. NMR relies on specific isotopic nuclei, such as (13)C and (15)N, for detection and, therefore, isotopic labeling is an important sample preparation step prior to in-depth structural characterization of proteins. The goal of this study was to develop a robust quantitative assay for assessing isotopic labeling in proteins while retaining information on the extent of labeling for individual amino acids. METHODS Complete digestion of proteins by acid hydrolysis was followed by derivatization of free amino acids with 6-aminoquinolyl N-hydroxysuccinimidyl carbamate (AQC) forming derivatives having identical MS/MS fragmentation behavior. Precursor ion scanning on a hybrid quadrupole-linear ion trap platform was used for amino acid analysis and determining isotopic labeling of proteins. RESULTS Using a set of isotope-labeled amino acid standards mixed with their unlabeled counterparts, the method was validated for accurately measuring % isotopic contribution. We then applied the method for determining the (13)C isotopic content of algal proteins during a feeding study using (13)C(6)-glucose- or (13)C-bicarbonate-supplemented culture media as well as the level of labeling in mussel byssal threads obtained after feeding with labeled algae. CONCLUSIONS This method is ideally suited for assessing the extent of protein labeling prior to NMR studies, where the isotopic labeling is a determining factor in the quality of resulting protein spectra, and can be applied to a multitude of different biological samples.
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Affiliation(s)
- André LeBlanc
- Université du Québec à Montréal, Chemistry Department, Montréal, QC, Canada
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8
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Quantifying the fraction of alanine residues in an α-helical conformation in hornet silk using solid-state NMR. Polym J 2012. [DOI: 10.1038/pj.2012.93] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Umair S, Bland R, Simpson H. Glutamate synthase, but not GABA shunt enzymes, contributes to nitrogen metabolism of the sheep abomasal nematode parasites Haemonchus contortus and Teladorsagia circumcincta. Exp Parasitol 2011; 127:9-13. [DOI: 10.1016/j.exppara.2010.05.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 04/22/2010] [Accepted: 05/25/2010] [Indexed: 10/19/2022]
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10
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Nitrogen excretion by the sheep abomasal parasite Teladorsagia circumcincta. Exp Parasitol 2009; 123:17-23. [DOI: 10.1016/j.exppara.2009.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2009] [Revised: 03/30/2009] [Accepted: 05/07/2009] [Indexed: 10/20/2022]
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Scaraffia PY, Isoe J, Murillo A, Wells MA. Ammonia metabolism in Aedes aegypti. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2005; 35:491-503. [PMID: 15804581 DOI: 10.1016/j.ibmb.2005.01.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Revised: 12/13/2004] [Accepted: 01/26/2005] [Indexed: 05/24/2023]
Abstract
We investigated the mechanisms by which Aedes aegypti mosquitoes are able to metabolize ammonia. When females were given access to solutions containing NH(4)Cl or to a blood meal, hemolymph glutamine and proline concentrations increased markedly, indicating that ammonium/ammonia can be removed from the body through the synthesis of these two amino acids. The importance of glutamine synthetase was shown when an inhibitor of the enzyme was added to the meal causing the glutamine concentration in hemolymph to decrease significantly, while the proline concentration increased dramatically. Unexpectedly, we found an important role for glutamate synthase. When mosquitoes were fed azaserine, an inhibitor of glutamate synthase, the glutamine concentration increased and the proline concentration decreased significantly. This confirms the presence of glutamate synthase in mosquitoes and suggests that this enzyme contributes to the production of glutamate for proline synthesis. Several key enzymes related to ammonium/ammonia metabolism showed activity in homogenates of mosquito fat body and midgut. The mosquito genes encoding glutamate dehydrogenase, glutamine synthetase, glutamate synthase, pyrroline-5-carboxylate synthase were cloned and sequenced. The mRNA expression patterns of these genes were examined by a real-time RT-PCR in fat body and midgut. The results show that female mosquitoes have evolved efficient mechanisms to detoxify large loads of ammonium/ammonia.
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Affiliation(s)
- Patricia Y Scaraffia
- Department of Biochemistry and Molecular Biophysics, The University of Arizona, Tucson, AZ 85721-0088, USA
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12
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Hess S, van Beek J, Pannell LK. Acid hydrolysis of silk fibroins and determination of the enrichment of isotopically labeled amino acids using precolumn derivatization and high-performance liquid chromatography-electrospray ionization-mass spectrometry. Anal Biochem 2002; 311:19-26. [PMID: 12441148 DOI: 10.1016/s0003-2697(02)00402-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Silk fibroins from moth larvae and spiders are composed of highly repetitive Ala- and Gly-rich blocks that determine their structure, properties, and function. To investigate the metabolic integration of isotopically labeled amino acids in the excreted silk, the enrichment of ingested tracers was determined after acid hydrolysis of the fibroins. Thus, spiders and moth larvae were fed with stable isotope tracers such as [1-13C]Ala or [1-13C]Gly and silked. After hydrolysis of the silk proteins, the corresponding amino acids were derivatized with Nalpha-(2,4-dinitro-5-fluorophenyl)-L-alaninamide (Marfey's reagent) and separated by liquid chromatography. The isotopical enrichment of the amino acids was determined by online electrospray mass spectrometry and calculated by newly developed software. Depending on the feeding protocol, enrichments of up to 58% in Gly and 31% in Ala were found in the investigated silks. The highly enriched silk fibroins are suitable for further structural investigation such as solid-state nuclear magnetic resonance.
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Affiliation(s)
- Sonja Hess
- Structural Mass Spectrometry Facility, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 8, Rm B2A27, Bethesda, MD 20892-0805, USA.
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Hirayama C, Nakamura M. Regulation of glutamine metabolism during the development of Bombyx mori larvae. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1571:131-7. [PMID: 12049793 DOI: 10.1016/s0304-4165(02)00207-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Waste ammonia is re-assimilated into amino acids via the amide group of glutamine and the amino group of glutamate (i.e. through glutamine synthetase/glutamate synthase pathway) for silk synthesis in the silkworm, Bombyx mori, in the last larval stadium. Glutamine concentration in hemolymph gradually decreased with the progress of the fifth instar and it remained at very low levels during the spinning stage, then followed by a sharp increase at the larval-pupal ecdysis. The changes in glutamine synthetase (GS) activity in silkworm tissues were relatively small through the larval development, while the changes in glutamate synthase (GOGAT) activity, especially in the posterior silk glands, were more drastic. In addition, activities of GOGAT in the tissues were much higher than those of the other enzymes involved in glutamine utilization, suggesting that glutamine pool was regulated mainly by the changes in GOGAT activity. Western blot analysis indicated that the changes in GOGAT protein level correlated with the changes in GOGAT activity. Topical application of a juvenile hormone analogue, methoprene, induced an accumulation of glutamine in the hemolymph of the fifth instar larvae. The levels of GOGAT protein and activity in the tissues of the methoprene treated larvae were much lower than those of the control larvae, whereas the methoprene treatment had no effect on the levels of GS activity. In conclusion, GOGAT expression promoted by reduction of juvenile hormone titer is quite important for enhanced utilization of nitrogen for synthesis of silk protein during the last larval instar.
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Affiliation(s)
- Chikara Hirayama
- National Institute of Agrobiological Sciences, Ohwashi, Tsukuba, Ibaraki, 305-8634, Japan.
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