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Windfelder AG, Steinbart J, Graser L, Scherberich J, Krombach GA, Vilcinskas A. An enteric ultrastructural surface atlas of the model insect Manducasexta. iScience 2024; 27:109410. [PMID: 38558941 PMCID: PMC10981077 DOI: 10.1016/j.isci.2024.109410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/02/2024] [Accepted: 02/29/2024] [Indexed: 04/04/2024] Open
Abstract
The tobacco hornworm is a laboratory model that is particularly suitable for analyzing gut inflammation, but a physiological reference standard is currently unavailable. Here, we present a surface atlas of the healthy hornworm gut generated by scanning electron microscopy and nano-computed tomography. This comprehensive overview of the gut surface reveals morphological differences between the anterior, middle, and posterior midgut, allowing the screening of aberrant gut phenotypes while accommodating normal physiological variations. We estimated a total resorptive midgut surface of 0.42 m2 for L5d6 larvae, revealing its remarkable size. Our data will support allometric scaling and dose conversion from Manduca sexta to mammals in preclinical research, embracing the 3R principles. We also observed non-uniform gut colonization by enterococci, characterized by dense biofilms in the pyloric cone and downstream of the pylorus associated with pore and spine structures in the hindgut intima, indicating a putative immunosurveillance function in the lepidopteran hindgut.
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Affiliation(s)
- Anton G. Windfelder
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Giessen, Germany
- Experimental Radiology, Department of Diagnostic and Interventional Radiology, University-Hospital Giessen, Justus Liebig University Giessen, Giessen, Germany
| | - Jessica Steinbart
- Experimental Radiology, Department of Diagnostic and Interventional Radiology, University-Hospital Giessen, Justus Liebig University Giessen, Giessen, Germany
| | - Leonie Graser
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Giessen, Germany
| | - Jan Scherberich
- Experimental Radiology, Department of Diagnostic and Interventional Radiology, University-Hospital Giessen, Justus Liebig University Giessen, Giessen, Germany
| | - Gabriele A. Krombach
- Experimental Radiology, Department of Diagnostic and Interventional Radiology, University-Hospital Giessen, Justus Liebig University Giessen, Giessen, Germany
- Department of Diagnostic and Interventional Radiology, University-Hospital Giessen, Giessen, Germany
| | - Andreas Vilcinskas
- Branch for Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Giessen, Germany
- Institute for Insect Biotechnology, Department of Applied Entomology, Justus Liebig University Giessen, Giessen, Germany
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Awais MM, Fei S, Xia J, Feng M, Sun J. Insights into midgut cell types and their crucial role in antiviral immunity in the lepidopteran model Bombyx mori. Front Immunol 2024; 15:1349428. [PMID: 38420120 PMCID: PMC10899340 DOI: 10.3389/fimmu.2024.1349428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/18/2024] [Indexed: 03/02/2024] Open
Abstract
The midgut, a vital component of the digestive system in arthropods, serves as an interface between ingested food and the insect's physiology, playing a pivotal role in nutrient absorption and immune defense mechanisms. Distinct cell types, including columnar, enteroendocrine, goblet and regenerative cells, comprise the midgut in insects and contribute to its robust immune response. Enterocytes/columnar cells, the primary absorptive cells, facilitate the immune response through enzyme secretions, while regenerative cells play a crucial role in maintaining midgut integrity by continuously replenishing damaged cells and maintaining the continuity of the immune defense. The peritrophic membrane is vital to the insect's innate immunity, shielding the midgut from pathogens and abrasive food particles. Midgut juice, a mixture of digestive enzymes and antimicrobial factors, further contributes to the insect's immune defense, helping the insect to combat invading pathogens and regulate the midgut microbial community. The cutting-edge single-cell transcriptomics also unveiled previously unrecognized subpopulations within the insect midgut cells and elucidated the striking similarities between the gastrointestinal tracts of insects and higher mammals. Understanding the intricate interplay between midgut cell types provides valuable insights into insect immunity. This review provides a solid foundation for unraveling the complex roles of the midgut, not only in digestion but also in immunity. Moreover, this review will discuss the novel immune strategies led by the midgut employed by insects to combat invading pathogens, ultimately contributing to the broader understanding of insect physiology and defense mechanisms.
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Affiliation(s)
| | | | | | - Min Feng
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
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Ibrahim SP, Dias RO, Ferreira C, Silva CP, Terra WR. Histochemistry and transcriptomics of mucins and peritrophic membrane (PM) proteins along the midgut of a beetle with incomplete PM and their complementary function. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 162:104027. [PMID: 37832798 DOI: 10.1016/j.ibmb.2023.104027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/04/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023]
Abstract
The midgut of Zabrotes subfasciatus (Coleoptera) and other insects may have regions lacking a peritrophic membrane (matrix, PM) and covered with a jelly-like material known as peritrophic gel. This work was undertaken to test the hypothesis that the peritrophic gel is a vertebrate-like mucus. By histochemistry we identified mucins along the whole midgut, which contrasts with the known occurrence of PM only at the posterior midgut. We also analyzed the expression of the genes coding for mucus-forming mucins (Mf-mucins), peritrophins, chitin synthases and chitin deacetylases along the midgut and carcass (insect without midgut) by RNA-seq. Mf-mucins were identified as proteins with high O-glycosylation and multiple tandem repeats of Pro/Thr/Ser residues. Peritrophins were separated into PM proteins, cuticular proteins analogous to peritrophins (CPAPs) and ubiquitous-chitin-binding domain-(CBD)-containing proteins (UCBPs). PM proteins have at least 3, CPAP one or 3, and UCBPs have a varied number of CBDs. PM proteins are more expressed at midgut, CPAP at the carcass, and UCBP at both. The results showed that most PM proteins are mainly expressed at the posterior midgut, together with midgut chitin synthase and chitin deacetylase, and in agreement with the presence of PM only at the posterior midgut by visual inspection. The excretion of most midgut chitinase is avoided, suggesting that the shortened PM is functional. Mf-mucins are expressed along the whole midgut, probably forming the extracellular mucus layer observed by histochemistry. Thus, the lack of PM at anterior and middle midgut causes the exposure of a mucus, which may correspond to the previously described peritrophic gel. The putative functional interplay of mucus and PM is discussed. The major role of mucus is proposed to be tissue protection and of PM to enhancing digestive efficiency by allowing enzyme recycling.
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Affiliation(s)
- Samira P Ibrahim
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, C.P. 476, Florianópolis, 88040-900, Brazil
| | - Renata O Dias
- Departamento de Genética, Instituto de Ciências Biológicas, Universidade, Federal de Goiás, Av. Esperança s/n, 74690-900, Goiânia, Brazil
| | - Clelia Ferreira
- Departamento de Bioquímica, Instituto de Química, Universidade de São, Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, Brazil
| | - Carlos P Silva
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, C.P. 476, Florianópolis, 88040-900, Brazil; Departamento de Bioquímica, Instituto de Química, Universidade de São, Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, Brazil.
| | - Walter R Terra
- Departamento de Bioquímica, Instituto de Química, Universidade de São, Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, Brazil.
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Zhu Q, Li F, Shu Q, Feng P, Wang Y, Dai M, Mao T, Sun H, Wei J, Li B. Disruption of peritrophic matrix chitin metabolism and gut immune by chlorantraniliprole results in pathogenic bacterial infection in Bombyx mori. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 193:105430. [PMID: 37248008 DOI: 10.1016/j.pestbp.2023.105430] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 05/31/2023]
Abstract
Chlorantraniliprole (CAP) is widely used in pest control, and its environmental residues affect the disease resistance of non-target insect silkworms. Studies have demonstrated that changes in gut microbial communities of insects are associated with susceptibility to pathogens. In the present study, we examined the effects of CAP exposure on the immune system and gut microbial community structure of silkworms. The results showed that after 96 h of exposure to low-concentration CAP, the peritrophic matrix (PM) of silkworm larvae was disrupted, and pathogenic bacteria invaded hemolymph. The trehalase activity in the midgut was significantly decreased, while the activities of chitinase, β-N-acetylglucosaminidase, and chitin deacetylase were increased considerably, resulting in decreased chitin content in PM. In addition, exposure to CAP reduced the expressions of key genes in the Toll, IMD, and JAK/STAT pathways, ultimately leading to the downregulation of antimicrobial peptides (AMPs) genes and alterations in the structure of the gut microbial community. Therefore, after infection with the conditional pathogen Enterobacter cloacae (E. cloacae), CAP-exposed individuals exhibited significantly lower body weight and higher mortality. These findings showed that exposure to low-concentration CAP impacted the biological defense system of silkworms, changed the gut microbial community structure, and increased silkworms' susceptibility to bacterial diseases. Collectively, these findings provided a new perspective for the safety evaluation of low-concentration CAP exposure in sericulture.
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Affiliation(s)
- Qingyu Zhu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Fanchi Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; Sericulture Institute of Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Qilong Shu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Piao Feng
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Yuanfei Wang
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Minli Dai
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Tingting Mao
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Haina Sun
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; Sericulture Institute of Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Jing Wei
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; Sericulture Institute of Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Bing Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; Sericulture Institute of Soochow University, Suzhou, Jiangsu 215123, PR China.
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Makwana P, Rahul K, Ito K, Subhadra B. Diversity of Antimicrobial Peptides in Silkworm. Life (Basel) 2023; 13:life13051161. [PMID: 37240807 DOI: 10.3390/life13051161] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/01/2023] [Accepted: 05/07/2023] [Indexed: 05/28/2023] Open
Abstract
Antimicrobial resistance is a phenomenon that the present-day world is witnessing that poses a serious threat to global health. The decline in the development of novel therapeutics over the last couple of decades has exacerbated the situation further. In this scenario, the pursuit of new alternative therapeutics to commonly used antibiotics has gained predominance amongst researchers across the world. Antimicrobial peptides (AMPs) from natural sources have drawn significant interest in the recent years as promising pharmacological substitutes over the conventional antibiotics. The most notable advantage of AMPs is that microorganisms cannot develop resistance to them. Insects represent one of the potential sources of AMPs, which are synthesized as part of an innate immune defence against invading pathogens. AMPs from different insects have been extensively studied, and silkworm is one of them. Diverse classes of AMPs (including attacins, cecropins, defensins, enbocins, gloverins, lebocins and moricins) were identified from silkworm that exhibit antimicrobial property against bacteria, fungi and viruses, indicating their potential therapeutic benefits. This review briefs about the immune responses of silkworm to invading pathogens, the isolation of AMPs from silkworms, AMPs reported in silkworms and their activity against various microorganisms.
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Affiliation(s)
- Pooja Makwana
- Central Sericultural Research & Training Institute, Central Silk Board, Ministry of Textiles, Government of India, Berhampore, Murshidabad 742101, West Bengal, India
| | - Kamidi Rahul
- Central Sericultural Research & Training Institute, Central Silk Board, Ministry of Textiles, Government of India, Berhampore, Murshidabad 742101, West Bengal, India
| | - Katsuhiko Ito
- Laboratory of Sericultural Science, Department of Science of Biological Production, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi 183-8509, Tokyo, Japan
| | - Bindu Subhadra
- Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, Long Island University, Brookville, New York, NY 11548, USA
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Zou H, Zhang B, Zou C, Ma W, Zhang S, Wang Z, Bi B, Li S, Gao J, Zhang C, Zhang G, Zhang J. Knockdown of GFAT disrupts chitin synthesis in Hyphantria cunea larvae. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 188:105245. [PMID: 36464356 DOI: 10.1016/j.pestbp.2022.105245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/13/2022] [Accepted: 09/13/2022] [Indexed: 06/17/2023]
Abstract
Glutamine-fructose-6-phosphate transaminase (GFAT) has been reported to regulate the hexosamine biosynthetic pathway as the first rate-limiting enzyme. As a key enzyme that catalyzes the substrate of glycosylation modification, which has a wide-ranging effect on cellular functions. However, there are few studies on the relationship between GFAT and chitin metabolism in insects. In the present study, the GFAT gene from Hyphantria cunea was identified based on transcriptome and bioinformatic analysis. The role of HcGFAT in regulating development and chitin synthesis was analyzed by RNA interference (RNAi) in H. cunea larvae. The full-length HcGFAT gene (2028 bp) encodes a 676 amino acid (aa) polypeptide had typical structural features of the SIS and Gn_AT_II superfamily. Phylogenetic analyses showed that GFAT of H. cunea shares the highest homology and identity with GFAT of Ostrinia furnacalis. Expression profiles indicated that HcGFAT was expressed throughout larval, pupal and three tissues (midgut, fat body, epidermis), and highly expressed in the last instar of larvae and strongly expressed in epidermis among three tissues. Bioassay results showed that knockdown of HcGFAT repressed larval growth and development, resulting in a significant loss of larval body weight. Meanwhile, HcGFAT knockdown also significantly caused larval developmental deformity. Knockdown of HcGFAT regulated the expression of four other critical genes in the chitin synthesis pathway (HcGNA, HcPAGM, HcUAP, HcCHSA), and ultimately resulted in decreased chitin content in the epidermis. In summary, these findings indicated that GFAT plays a critical role in larval growth and development, as well as chitin synthesis in H. cunea.
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Affiliation(s)
- Hang Zou
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Bowen Zhang
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Chuanshan Zou
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Weihu Ma
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Shengyu Zhang
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Ze Wang
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Bing Bi
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Siyi Li
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
| | - Jinhui Gao
- Yichun Branch of Heilongjiang Academy of Forestry, Yichun 153000, PR China
| | - Chunxia Zhang
- Kuduer Forestry Bureau of Inner Mongolia, Hulunbuir 022159, PR China
| | - Guocai Zhang
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China.
| | - Jie Zhang
- School of Forestry, Northeast Forestry University, Harbin 150040, PR China
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Wang Q, Sun Z, Ma S, Liu X, Xia H, Chen K. Molecular mechanism and potential application of bacterial infection in the silkworm, Bombyx mori. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 131:104381. [PMID: 35245606 DOI: 10.1016/j.dci.2022.104381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/14/2022] [Accepted: 02/27/2022] [Indexed: 06/14/2023]
Abstract
As a representative species of Lepidoptera, Bombyx mori has been widely studied and applied. However, bacterial infection has always been an important pathogen threatening the growth of silkworms. Bombyx mori can resist various pathogenic bacteria through their own physical barrier and innate immune system. However, compared with other insects, such as Drosophila melanogaster, research on the antibacterial mechanism of silkworms is still in its infancy. This review systematically summarized the routes of bacterial infection in silkworms, the antibacterial mechanism of silkworms after ingestion or wounding infection, and the intestinal bacteria and infection of silkworms. Finally, we will discuss silkworms as a model animal for studying bacterial infectious diseases and screening antibacterial drugs.
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Affiliation(s)
- Qiang Wang
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Zhonghe Sun
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Shangshang Ma
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Xiaoyong Liu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Hengchuan Xia
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China
| | - Keping Chen
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, PR China.
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Shen Y, Chen G, Zhao S, Wu X. Genome-wide identification of lipases in silkworm (Bombyx mori) and their spatio-temporal expression in larval midgut. Gene 2021; 813:146121. [PMID: 34915049 DOI: 10.1016/j.gene.2021.146121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/20/2021] [Accepted: 12/06/2021] [Indexed: 01/15/2023]
Abstract
Lipases play crucial roles in food digestion by degrading dietary lipids into free fatty acids and glycerols. The domesticated silkworm (Bombyx mori) has been widely used as an important Lepidopteran model for decades. However, little is known about the lipase gene family in the silkworm, especially their hydrolytic activities as digestive enzymes. In this study, a total of 38 lipase genes were identified in the silkworm genome. Phylogenetic analysis indicated that they were divided into three major groups. Twelve lipases were confirmed to be expressed in the midgut at both transcriptional and translational levels. They were grouped into the same gene cluster, suggesting that they could have similar physiological functions. Quantitative real-time PCR (qRT-PCR) analyses indicated that lipases were mainly expressed in anterior and middle midgut regions, and their expression levels varied greatly along the length of midgut. A majority of lipases were down-regulated in the midgut when larvae stopped feeding. However, a unique lipase gene (Bmlip10583) showed low expression level during feeding stage, but it was significantly up-regulated during the larvae-pupae transition. These results demonstrated that expression of silkworm lipases was spatially and temporally regulated in the midgut during larval development. Taken together, our results provide a fundamental research of the lipase gene family in the silkworm.
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Affiliation(s)
- Yunwang Shen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou 310058, China
| | - Guanping Chen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou 310058, China
| | - Shudi Zhao
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou 310058, China
| | - Xiaofeng Wu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou 310058, China.
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