1
|
Yu S, Zheng H, Ye X, Dai X, Wang X, Zhao S, Dai X, Zhong B. TALEN-mediated homologous-recombination-based fibroin light chain in-fusion expression system in Bombyx mori. Front Bioeng Biotechnol 2024; 12:1399629. [PMID: 38832132 PMCID: PMC11144906 DOI: 10.3389/fbioe.2024.1399629] [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: 03/12/2024] [Accepted: 04/25/2024] [Indexed: 06/05/2024] Open
Abstract
Silkworm was the first domesticated insect and has important economic value. It has also become an ideal model organism with applications in genetic and expression studies. In recent years, the use of transgenic strategies has made the silkworm silk gland an attractive bioreactor for the production of recombinant proteins, in particular, piggyBac-mediated transgenes. However, owing to differences in regulatory elements such as promoters, the expression levels of exogenous proteins have not reached expectations. Here, we used targeted gene editing to achieve site-specific integration of exogenous genes on genomic DNA and established the fibroin light chain (FibL) in-fusion expression system by TALEN-mediated homology-directed recombination. First, the histidine-rich cuticular protein (CP) was successfully site-directed inserted into the native FibL, and the FibL-CP fusion gene was correctly transcribed and expressed in the posterior silk gland under the control of the endogenous FibL promoter, with a protein expression level comparable with that of the native FibL protein. Moreover, we showed based on molecular docking that the fusion of FibL with cuticular protein may have a negative effect on disulfide bond formation between the C-terminal domain of fibroin heavy chain (FibH) and FibL-CP, resulting in abnormal spinning and cocoon in homozygotes, indicating a significant role of FibL in silk protein formation and secretion. Our results demonstrate the feasibility of using the FibL fusion system to express exogenous proteins in silkworm. We expect that this bioreactor system will be used to produce more proteins of interest, expanding the application value of the silk gland bioreactor.
Collapse
Affiliation(s)
- Shihua Yu
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou, China
| | - Huoqing Zheng
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou, China
| | - Xiaogang Ye
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou, China
| | - Xiangping Dai
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou, China
| | - Xinqiu Wang
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou, China
| | - Shuo Zhao
- Department of Laboratory Medicine, The First Affiliated Hospital of Henan University of Chinese Medicine, Zheng Zhou, China
| | - Xiaoyan Dai
- Suposik Bioscience Technologies Ltd., Jiaxing, China
| | - Boxiong Zhong
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou, China
| |
Collapse
|
2
|
Iwabuchi K, Miyamoto K, Jouraku A, Takasu Y, Iizuka T, Adegawa S, Li X, Sato R, Watanabe K. ABC transporter subfamily B1 as a susceptibility determinant of Bombyx mori larvae to Cry1Ba, Cry1Ia and Cry9Da toxins. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 163:104030. [PMID: 37952901 DOI: 10.1016/j.ibmb.2023.104030] [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: 06/19/2023] [Revised: 10/05/2023] [Accepted: 10/28/2023] [Indexed: 11/14/2023]
Abstract
ATP binding cassette (ABC) transporters are a diverse family of transmembrane proteins. Specific subfamily members expressed in the lepidopteran midgut can act as susceptibility determinants for several insecticidal Bt Cry proteins. However, the susceptibility determinants to many Cry toxins still remain unclear. Therefore, we knocked out a series of ABC transporters that are highly expressed in the midgut of Bombyx mori larvae by transcription activator-like effector nuclease (TALEN)-mediated gene editing, and the lineages that became resistant to Cry toxins were searched by toxin overlay bioassay. As a result, the B. mori ABC transporter subfamily B1 (BmABCB1) knockout lineage showed 19.17-fold resistance to Cry1Ba, 876.2-fold resistance to Cry1Ia, and 29.1-fold resistance to Cry9Da, suggesting that BmABCB1 is the determinant of susceptibility to these toxins. BmABCC2 and BmABCC3 have been shown to be susceptibility determinants based on their function as receptors. Therefore, we next heterologously expressed these ABC transporters in HEK293T cells and performed a cell swelling assay to examine whether these molecules could exert receptor functions. As a result, BmABCB1-expressing cells showed swelling response to Cry1Ia and Cry9Da, and cells expressing PxABCB1, which is the Plutella xylostella ortholog of BmABCB1, showed swelling for Cry1Ba, suggesting that ABCB1 is a susceptibility determinant by functioning as a receptor to these toxins. Furthermore, in order to clarify how high binding affinity is based on receptor function, we performed surface plasmon resonance analysis and found that each KD of Cry1Ba, Cry1Ia, and Cry9Da to BmABCB1 were 7.69 × 10-8 M, 2.19 × 10-9 M, and 4.17 × 10-6 M respectively.
Collapse
Affiliation(s)
- Kana Iwabuchi
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo, 184-8588, Japan
| | - Kazuhisa Miyamoto
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Akiya Jouraku
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Yoko Takasu
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Tetsuya Iizuka
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Satomi Adegawa
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo, 184-8588, Japan
| | - Xiaoyi Li
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo, 184-8588, Japan
| | - Ryoichi Sato
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo, 184-8588, Japan.
| | - Kenji Watanabe
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki, 305-8634, Japan.
| |
Collapse
|
3
|
Takasu Y, Yamada N, Kojima K, Iga M, Yukuhiro F, Iizuka T, Yoshioka T. Fibroin heavy chain gene replacement with a highly ordered synthetic repeat sequence in Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 161:104002. [PMID: 37657611 DOI: 10.1016/j.ibmb.2023.104002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/08/2023] [Accepted: 08/29/2023] [Indexed: 09/03/2023]
Abstract
The exceptional quality of silkworm silk is attributed to the amino acid sequence of its fibroin heavy chain (Fib-H) protein. The large central domain of Fib-H, which consists of glycine- and alanine-rich crystalline regions interspersed with amorphous motifs of approximately 30 amino acid residues, is considered crucial for fibrilization and determines the properties of the silk fiber. We established a technical platform to modify the Fib-H core region systematically using transcription activator-like effector nuclease-mediated homologous recombination through a somatic and germline gene knockin assay along with PCR-based screening. This efficient knockin system was used to generate a silkworm strain carrying a mutant Fib-H allele, in which the core region was replaced with a highly ordered synthetic repeat sequence of a length comparable with native Fib-H core. Heterozygous knockin mutants produced seemingly normal cocoons, whereas homozygotes did not and exhibited considerable degradation in their posterior silk glands (PSGs). Cross-sectional examination of the PSG lumen and tensile tests conducted on reeled silk threads indicated that the mutant Fib-H, which exhibited reduced stability in the PSG cells and lumen, affected the mechanical properties of the fiber. Thus, sequence manipulation of the Fib-H core domain was identified as a crucial step in successfully creating artificial silk using knockin technology.
Collapse
Affiliation(s)
- Yoko Takasu
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan.
| | - Nobuto Yamada
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Katsura Kojima
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Masatoshi Iga
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Fumiko Yukuhiro
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Tetsuya Iizuka
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Taiyo Yoshioka
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| |
Collapse
|
4
|
Tomihara K, Kiuchi T. Disruption of a BTB-ZF transcription factor causes female sterility and melanization in the larval body of the silkworm, Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 159:103982. [PMID: 37356736 DOI: 10.1016/j.ibmb.2023.103982] [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: 04/02/2023] [Revised: 05/31/2023] [Accepted: 06/16/2023] [Indexed: 06/27/2023]
Abstract
The dilute black (bd) of the silkworm Bombyx mori is a recessive mutant that produces a grayish-black color in the larval integument, instead of the characteristic white color found in wild-type larvae. In addition, eggs produced by bd females are sterile due to a deficiency in the micropylar apparatus. We identified candidate genes responsible for the bd phenotype using publicly available RNA-seq data. One of these candidate genes was homologous to the maternal gene required for meiosis (mamo) of Drosophila melanogaster, which encodes a broad-complex, tramtrack, and bric-à-brac-zinc finger (BTB-ZF) transcription factor essential for female fertility. In three independent bd strains, the expression of the B. mori mamo (Bmmamo) was downregulated in the larval integument. Using a CRISPR/Cas9-mediated knockout strategy, we found that Bmmamo knockout mutants exhibit a grayish-black color in the larval integument and female infertility. Moreover, larvae obtained from the complementation cross between bd/+ mutants and heterozygous knockouts for the Bmmamo also exhibited a grayish-black color, indicating that Bmmamo is responsible for the bd phenotype. Gene expression analysis using Bmmamo knockout mutants suggested that the BmMamo protein suppresses the expression of melanin synthesis genes. Previous comparative genome analysis revealed that the Bmmamo was selected during silkworm domestication, and we found that Bmmamo expression in the larval integument is higher in B. mori than in the wild silkworm B. mandarina, suggesting that the Bmmamo is involved in domestication-associated pigmentation changes of the silkworm.
Collapse
Affiliation(s)
- Kenta Tomihara
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan.
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan.
| |
Collapse
|
5
|
Zabelina V, Vrchotova M, Yonemura N, Sezutsu H, Tamura T, Klymenko V, Sehnal F, Zurovec M, Sehadova H, Sauman I. The Exact Timing of Microinjection of Parthenogenetic Silkworm Embryos Is Crucial for Their Successful Transgenesis. Front Physiol 2022; 13:822900. [PMID: 35399273 PMCID: PMC8990321 DOI: 10.3389/fphys.2022.822900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/28/2022] [Indexed: 12/03/2022] Open
Abstract
The use of parthenogenetic silkworm (Bombyx mori) strains, which eliminate the problem of recombination, is a useful tool for maintaining transgenic clonal lines. The generation of genetically identical individuals is becoming an important tool in genetic engineering, allowing replication of an existing advantageous trait combination without the mixing that occurs during sexual reproduction. Thus, an animal with a particular genetic modification, such as the ability to produce transgenic proteins, can reproduce more rapidly than by natural mating. One obstacle to the widespread use of parthenogenesis in silkworm genetic engineering is the relatively low efficiency of downstream transgenesis techniques. In this work, we seek to optimize the use of transgenesis in conjunction with the production of parthenogenetic individuals. We found that a very important parameter for the introduction of foreign genes into a parthenogenetic strain is the precise timing of embryo microinjection. Our modification of the original method increased the efficiency of transgene injection as well as the survival rate of injected embryos. We also provide a detailed description of the methodological procedure including a graphical overview of the entire protocol.
Collapse
Affiliation(s)
- Valeriya Zabelina
- Biology Center CAS, Institute of Entomology, České Budějovice, Czechia.,Faculty of Science, University of South Bohemia, České Budějovice, Czechia.,National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Marketa Vrchotova
- Biology Center CAS, Institute of Entomology, České Budějovice, Czechia.,Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Naoyuki Yonemura
- National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Hideki Sezutsu
- National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Toshiki Tamura
- National Agriculture and Food Research Organization, Tsukuba, Japan.,Silk Sciences and Technology Research Institute, Ibaraki, Japan
| | - Vyacheslav Klymenko
- Faculty of Automation and Information Technology in Management, Ryazan State Radio Engineering University, Ryazan, Russia
| | - Frantisek Sehnal
- Biology Center CAS, Institute of Entomology, České Budějovice, Czechia.,Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Michal Zurovec
- Biology Center CAS, Institute of Entomology, České Budějovice, Czechia.,Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Hana Sehadova
- Biology Center CAS, Institute of Entomology, České Budějovice, Czechia.,Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Ivo Sauman
- Biology Center CAS, Institute of Entomology, České Budějovice, Czechia.,Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| |
Collapse
|
6
|
Heryanto C, Hanly JJ, Mazo-Vargas A, Tendolkar A, Martin A. Mapping and CRISPR homology-directed repair of a recessive white eye mutation in Plodia moths. iScience 2022; 25:103885. [PMID: 35243245 PMCID: PMC8861637 DOI: 10.1016/j.isci.2022.103885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/23/2021] [Accepted: 01/11/2022] [Indexed: 11/29/2022] Open
Abstract
The pantry moth Plodia interpunctella is a worldwide pest of stored food products and a promising laboratory model system for lepidopteran functional genomics. Here we describe efficient methods for precise genome editing in this insect. A spontaneous recessive white-eyed phenotype maps to a frameshift deletion (c.737delC) in the white gene. CRISPR NHEJ mutagenesis of white replicates this phenotype with high rates of somatic biallelic knockout. G0 individuals with mutant clones on both eyes produced 100% mutant progeny, making white an ideal marker for co-conversion when targeting other genes. CRISPR HDR experiments corrected c.737delC and reverted white eyes to a pigmented state in 37% of G0 mosaic adults. These repaired alleles showed practical rates of germline transmission in backcrosses, demonstrating the potential of the technique for precise genome editing. Plodia offers a promising avenue for research in this taxon because of its lab-ready features, egg injectability, and editability. Plodia pantry moths are an emerging model organism for functional genomics in Lepidoptera Spontaneous and CRISPR-induced white mutations yield recessive-white eye phenotypes CRISPR HDR repair with ssODN donor result in practical rates of base editing We provide optimized protocols for Plodia handling and genome editing
Collapse
|
7
|
Li Z, You L, Zhang Q, Yu Y, Tan A. A Targeted In-Fusion Expression System for Recombinant Protein Production in Bombyx mori. Front Genet 2022; 12:816075. [PMID: 35058975 PMCID: PMC8763709 DOI: 10.3389/fgene.2021.816075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 11/30/2021] [Indexed: 11/25/2022] Open
Abstract
The domesticated silkworm, Bombyx mori, is an economically important insect that synthesizes large amounts of silk proteins in its silk gland to make cocoons. In recent years, germline transformation strategies advanced the bioengineering of the silk gland as an ideal bioreactor for mass production of recombinant proteins. However, the yield of exogenous proteins varied largely due to the random insertion and gene drift caused by canonical transposon-based transformation, calling for site-specific and stable expression systems. In the current study, we established a targeted in-fusion expression system by using the transcription activator-like effector nuclease (TALEN)-mediated targeted insertion to target genomic locus of sericin, one of the major silk proteins. We successfully generated chimeric Sericin1-EGFP (Ser-2A-EGFP) transformant, producing up to 3.1% (w/w) of EGFP protein in the cocoon shell. With this strategy, we further expressed the medically important human epidermal growth factor (hEGF) and the protein yield in both middle silk glands, and cocoon shells reached to more than 15-fold higher than the canonical piggyBac-based transgenesis. This natural Sericin1 expression system provides a new strategy for producing recombinant proteins by using the silkworm silk gland as the bioreactor.
Collapse
Affiliation(s)
- Zhiqian Li
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China.,Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Lang You
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Qichao Zhang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Ye Yu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| | - Anjiang Tan
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.,Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, China
| |
Collapse
|
8
|
Wang Y, Adegawa S, Miyamoto K, Takasu Y, Iizuka T, Wada S, Mang D, Li X, Kim S, Sato R, Watanabe K. ATP-binding cassette transporter subfamily C members 2, 3 and cadherin protein are susceptibility-determining factors in Bombyx mori for multiple Bacillus thuringiensis Cry1 toxins. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2021; 139:103649. [PMID: 34560243 DOI: 10.1016/j.ibmb.2021.103649] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
Field-evolved resistance of insect pests to Bacillus thuringiensis (Bt) toxins (Cry toxins) is a threat to the efficacy of Bt-based bio-insecticides and transgenic crops. Recent reports have suggested that ATP-binding cassette transporter subfamily C2 (ABCC2) and cadherin-like receptor play important roles in conferring susceptibility to Cry1 toxins. However, the receptors involved in Bt susceptibility in each insect remain unclear. To determine the receptors that are involved in the susceptibility of Bombyx mori to Cry1 toxins (1Ab, 1Ac and 1Fa), we conducted diet overlay bioassay using B. mori strains disrupted with one or two receptor (s) among BmABCC2, BmABCC3, and cadherin-like receptor (BtR175) generated by transcription activator-like effector nuclease (TALEN)-mediated gene editing. The single-knockout strains for BmABCC2 showed resistance to Cry1Ab and Cry1Ac, whereas only strains with double knockout of BmABCC2 and BmABCC3 exhibited high resistance to Cry1Fa. Progeny populations generated from the crossing of heterozygotes for BtR175 knockout allele included 25% theoretical homozygotes for the BtR175 knockout allele and they showed resistance to Cry1Ab and Cry1Ac. Then, through a cell swelling assay using Sf9 cells ectopically expressing the receptor, we analyzed the mechanisms underlying the different contributions of BmABCC2, BmABCC3, and BtR175 to larval susceptibility. The receptor activity of BmABCC2 for Cry1Ab and Cry1Ac was far higher than that of BmABCC3, and BtR175 synergistically enhanced the receptor activity of BmABCC2. This result well explained the important involvement of BmABCC2 and BtR175 in the larval susceptibility to Cry1A toxins. By contrast, the receptor activities of BmABCC2 and BmABCC3 for Cry1Fa were observed at a similar level and synergistic effect of BtR175 was small. This finding explains the equal importance of BmABCC2 and BmABCC3 and very small contribution of BtR175 on larval susceptibility to Cry1Fa. Thus, we demonstrated the different importance of BmABCC2, BmABCC3, and BtR175 to various Cry1 toxins as susceptibility-determining factors in B. mori larvae and the underlying basis for the observed differences. Furthermore, a weak correlation was indicated between the binding affinity and receptor activities of BmABCC2 and BmABCC3 to Cry1 toxins.
Collapse
Affiliation(s)
- Yonghao Wang
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan
| | - Satomi Adegawa
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan
| | - Kazuhisa Miyamoto
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Yoko Takasu
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Tetsuya Iizuka
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Sanae Wada
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Dingze Mang
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan
| | - Xiaoyi Li
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan
| | - Seungwon Kim
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan
| | - Ryoichi Sato
- Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Kenji Watanabe
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan.
| |
Collapse
|
9
|
5'-DMT-protected double-stranded DNA: Synthesis and competence to enzymatic reactions. Anal Biochem 2021; 617:114115. [PMID: 33508272 DOI: 10.1016/j.ab.2021.114115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/11/2021] [Accepted: 01/14/2021] [Indexed: 12/11/2022]
Abstract
The functionalization of 5'-OH group in nucleic acids is of significant value for molecular biology. In the current work we discovered that acid-labile 4,4'-dimethoxytrityl protecting group (DMT) of oligonucleotides (ONs) is stable under PCR conditions and does not interfere with activity of DNA polymerases. So application of 5'-DMT-protected ONs could allow producing both symmetric and asymmetric 5'-DMT-blocked double-stranded DNA (dsDNA) fragments. We demonstrated that the presence of thiol compounds (mercaptoethanol and dithiothreitol) in PCR mixture is undesirable for the stability of DMT-group. DMT-ONs can be successfully used during polymerase chain assembly of synthetic genes. We tested 5'-DMT dsDNA in blunt-end DNA ligation reaction by T4 DNA ligase and found that it could not be ligated with 5'-phosphorylated DNA fragments, namely linearized plasmid vector pJET1.2/blunt. Possible reason for this is steric hindrance created by bulky and rigid DMT-group, that prevents entering enzyme active site. We also demonstrated that 5'-DMT modification of dsDNA does not affect activity of T5 5',3'-exonuclease towards both ssDNA and dsDNA. Further screening of the exonucleases, sensitive to 5'-DMT-modification or search of ways to separate long 5'-DMT-ssDNA and 5'-OH-ssDNA could allow finding application of 5'-DMT-modified oligo- and polynucleotides.
Collapse
|
10
|
Functional Analysis of Adipokinetic Hormone Signaling in Bombyx mori. Cells 2020; 9:cells9122667. [PMID: 33322530 PMCID: PMC7764666 DOI: 10.3390/cells9122667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 11/17/2022] Open
Abstract
Insect adipokinetic hormones (AKHs) are short peptides produced in the corpora cardiaca and are responsible for mobilizing energy stores from the fat body to the hemolymph. Three related peptides, AKH1, AKH2, and AKH/corazonin-related peptide (ACP) as well as three AKH receptors have been reported in Bombyx mori. AKH1 and AKH2 are specific for the AKHR1 receptor, whereas ACP interacts with the other two AKHRs. To assess the effect of the two silkworm AKHs and ACP in the regulation of energy homeostasis we examined the expression pattern of the three peptides and their receptors as well as their effect on the level of carbohydrates and lipids in the hemolymph. Our results support the hypothesis that only AKH1 and AKH2 peptides together with the AKHR1 receptor are involved in the maintenance of energy homeostasis. Because Bombyx AKHR1 (BmAKHR1) seems to be a true AKHR we generated its mutation. The BmAKHR1 mutant larvae display significantly lower carbohydrate and lipid levels in the hemolymph and reduced sensitivity to starvation. Our study clarifies the role of BmAKHR1 in energy homeostasis.
Collapse
|
11
|
Li X, Miyamoto K, Takasu Y, Wada S, Iizuka T, Adegawa S, Sato R, Watanabe K. ATP-Binding Cassette Subfamily A Member 2 is a Functional Receptor for Bacillus thuringiensis Cry2A Toxins in Bombyx mori, but not for Cry1A, Cry1C, Cry1D, Cry1F, or Cry9A Toxins. Toxins (Basel) 2020; 12:E104. [PMID: 32041133 PMCID: PMC7076765 DOI: 10.3390/toxins12020104] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/01/2020] [Accepted: 02/03/2020] [Indexed: 11/29/2022] Open
Abstract
: Cry toxins are insecticidal proteins produced by Bacillus thuringiensis (Bt). They are used commercially to control insect pests since they are very active in specific insects and are harmless to the environment and human health. The gene encoding ATP-binding cassette subfamily A member 2 (ABCA2) was identified in an analysis of Cry2A toxin resistance genes. However, we do not have direct evidence for the role of ABCA2 for Cry2A toxins or why Cry2A toxin resistance does not cross to other Cry toxins. Therefore, we performed two experiments. First, we edited the ABCA2 sequence in Bombyx mori using transcription activator-like effector-nucleases (TALENs) and confirmed the susceptibility-determining ability in a diet overlay bioassay. Strains with C-terminal half-deleted BmABCA2 showed strong and specific resistance to Cry2A toxins; even strains carrying a deletion of 1 to 3 amino acids showed resistance. However, the C-terminal half-deleted strains did not show cross-resistance to other toxins. Second, we conducted a cell swelling assay and confirmed the specific ability of BmABCA2 to Cry2A toxins in HEK239 cells. Those demonstrated that BmABCA2 is a functional receptor for Cry2A toxins and that BmABCA2 deficiency-dependent Cry2A resistance does not confer cross-resistance to Cry1A, Cry1F, Cry1Ca, Cry1Da, or Cry9Aa toxins.
Collapse
Affiliation(s)
- Xiaoyi Li
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan; (X.L.); (S.A.)
| | - Kazuhisa Miyamoto
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan; (K.M.); (Y.T.); (S.W.); (T.I.)
| | - Yoko Takasu
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan; (K.M.); (Y.T.); (S.W.); (T.I.)
| | - Sanae Wada
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan; (K.M.); (Y.T.); (S.W.); (T.I.)
| | - Tetsuya Iizuka
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan; (K.M.); (Y.T.); (S.W.); (T.I.)
| | - Satomi Adegawa
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan; (X.L.); (S.A.)
| | - Ryoichi Sato
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan; (X.L.); (S.A.)
| | - Kenji Watanabe
- Institute of Agrobiological Sciences, NARO, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan; (K.M.); (Y.T.); (S.W.); (T.I.)
| |
Collapse
|
12
|
Zhang Z, Niu B, Ji D, Li M, Li K, James AA, Tan A, Huang Y. Silkworm genetic sexing through W chromosome-linked, targeted gene integration. Proc Natl Acad Sci U S A 2018; 115:8752-8756. [PMID: 30104361 PMCID: PMC6126770 DOI: 10.1073/pnas.1810945115] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Sex separation methods are critical for genetic sexing systems in commercial insect production and sterile insect techniques. Integration of selectable marker genes into a sex chromosome is particularly useful in insects with a heterogametic sex determination system. Here, we describe targeted gene integration of fluorescent marker expression cassettes into a randomly amplified polymorphic DNA (RAPD) marker region in the W chromosome of the lepidopteran model insect Bombyx mori using transcriptional activator-like effector nuclease (TALEN)-mediated genome editing. This silkworm strain shows ubiquitous female-specific red or green fluorescence from the embryonic to adult stages. Furthermore, we developed a binary, female-specific, embryonic lethality system combining the TALEN and the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technology. This system includes one strain with TALEN-mediated, W-specific Cas9 expression driven by the silkworm germ cell-specific nanos (nos) promoter and another strain with U6-derived single-guide RNA (sgRNA) expression targeting transformer 2 (tra2), an essential gene for silkworm embryonic development. Filial 1 (F1) hybrids exhibit complete female-specific lethality during embryonic stages. Our study provides a promising approach for B. mori genetic sexing and sheds light on developing sterile insect techniques in other insect species, especially in lepidopteran pests with WZ/ZZ sex chromosome systems.
Collapse
Affiliation(s)
- Zhongjie Zhang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 200032 Shanghai, China
- School of Life Science, East China Normal University, 200062 Shanghai, China
| | - Baolong Niu
- Sericultural Research Institute, Zhejiang Academy of Agricultural Sciences, 310021 Hangzhou, China
| | - Dongfeng Ji
- Sericultural Research Institute, Zhejiang Academy of Agricultural Sciences, 310021 Hangzhou, China
| | - Muwang Li
- Sericultural Research Institute, Jiangsu University of Science and Technology, 212018 Zhenjiang, China
| | - Kai Li
- School of Life Science, East China Normal University, 200062 Shanghai, China
| | - Anthony A James
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA 92697-3900;
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA 92697-3900
| | - Anjiang Tan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 200032 Shanghai, China;
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 200032 Shanghai, China;
| |
Collapse
|
13
|
Banerjee TD, Monteiro A. CRISPR-Cas9 Mediated Genome Editing in Bicyclus anynana Butterflies. Methods Protoc 2018; 1:E16. [PMID: 31164559 PMCID: PMC6526417 DOI: 10.3390/mps1020016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/04/2018] [Accepted: 05/04/2018] [Indexed: 01/19/2023] Open
Abstract
CRISPR-Cas9 is revolutionizing the field of genome editing in non-model organisms. The robustness, ease of use, replicability and affordability of the technology has resulted in its widespread adoption among researchers. The African butterfly Bicyclus anynana is an emerging model lepidopteran species in the field of evo-devo, with a sequenced genome and amenable to germ line transformation. However, efficient genome editing tools to accelerate the pace of functional genetic research in this species have only recently become available with CRISPR-Cas9 technology. Here, we provide a detailed explanation of the CRISPR-Cas9 protocol we follow in the lab. The technique has been successfully implemented to knock-out genes associated with eyespot development and melanin pigmentation.
Collapse
Affiliation(s)
- Tirtha Das Banerjee
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore.
| | - Antónia Monteiro
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore.
- Yale-NUS College, 10 College Avenue West, Singapore 138609, Singapore.
| |
Collapse
|
14
|
Khanal C, McGawley EC, Overstreet C, Stetina SR. The Elusive Search for Reniform Nematode Resistance in Cotton. PHYTOPATHOLOGY 2018; 108:532-541. [PMID: 29116883 DOI: 10.1094/phyto-09-17-0320-rvw] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The reniform nematode (Rotylenchulus reniformis Linford and Oliveira) has emerged as the most important plant-parasitic nematode of cotton in the United States cotton belt. Success in the development of reniform nematode-resistant upland cotton cultivars (Gossypium hirsutum L.) has not been realized despite over three decades of breeding efforts. Research approaches ranging from conventional breeding to triple species hybrids to marker-assisted selection have been employed to introgress reniform nematode resistance from other species of cotton into upland cultivars. Reniform nematode-resistant breeding lines derived from G. longicalyx were developed in 2007. However, these breeding lines displayed stunting symptoms and a hypersensitive response to reniform nematode infection. Subsequent breeding efforts focused on G. barbadense, G. aridum, G. armoreanum, and other species that have a high level of resistance to reniform nematode. Marker-assisted selection has greatly improved screening of reniform nematode-resistant lines. The use of advanced molecular techniques such as CRISPER-Cas9 systems and alternative ways such as delivery of suitable "cry" proteins and specific double-stranded RNA to nematodes will assist in developing resistant cultivars of cotton. In spite of the efforts of cotton breeders and nematologists, successes are limited only to the development of reniform nematode-resistant breeding lines. In this article, we provide an overview of the approaches employed to develop reniform nematode-resistant upland cotton cultivars in the past, progress to date, major obstacles, and some promising future research activity.
Collapse
Affiliation(s)
- Churamani Khanal
- First, second, and third authors: Louisiana State University AgCenter, Department of Plant Pathology and Crop Physiology, Baton Rouge 70803; and fourth author: United States Department of Agriculture-Agricultural Research Service, Crop Genetics Research Unit, P.O. Box 345, Stoneville, MS 38776
| | - Edward C McGawley
- First, second, and third authors: Louisiana State University AgCenter, Department of Plant Pathology and Crop Physiology, Baton Rouge 70803; and fourth author: United States Department of Agriculture-Agricultural Research Service, Crop Genetics Research Unit, P.O. Box 345, Stoneville, MS 38776
| | - Charles Overstreet
- First, second, and third authors: Louisiana State University AgCenter, Department of Plant Pathology and Crop Physiology, Baton Rouge 70803; and fourth author: United States Department of Agriculture-Agricultural Research Service, Crop Genetics Research Unit, P.O. Box 345, Stoneville, MS 38776
| | - Salliana R Stetina
- First, second, and third authors: Louisiana State University AgCenter, Department of Plant Pathology and Crop Physiology, Baton Rouge 70803; and fourth author: United States Department of Agriculture-Agricultural Research Service, Crop Genetics Research Unit, P.O. Box 345, Stoneville, MS 38776
| |
Collapse
|
15
|
Yoshioka T, Takasu Y, Sezutsu H, Kameda T. Genome Editing Advances the Structural Study of Silk. ACS Biomater Sci Eng 2018; 4:832-835. [DOI: 10.1021/acsbiomaterials.8b00043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
16
|
Ma S, Liu Y, Liu Y, Chang J, Zhang T, Wang X, Shi R, Lu W, Xia X, Zhao P, Xia Q. An integrated CRISPR Bombyx mori genome editing system with improved efficiency and expanded target sites. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 83:13-20. [PMID: 28189747 DOI: 10.1016/j.ibmb.2017.02.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/24/2016] [Accepted: 02/07/2017] [Indexed: 06/06/2023]
Abstract
Genome editing enabled unprecedented new opportunities for targeted genomic engineering of a wide variety of organisms ranging from microbes, plants, animals and even human embryos. The serial establishing and rapid applications of genome editing tools significantly accelerated Bombyx mori (B. mori) research during the past years. However, the only CRISPR system in B. mori was the commonly used SpCas9, which only recognize target sites containing NGG PAM sequence. In the present study, we first improve the efficiency of our previous established SpCas9 system by 3.5 folds. The improved high efficiency was also observed at several loci in both BmNs cells and B. mori embryos. Then to expand the target sites, we showed that two newly discovered CRISPR system, SaCas9 and AsCpf1, could also induce highly efficient site-specific genome editing in BmNs cells, and constructed an integrated CRISPR system. Genome-wide analysis of targetable sites was further conducted and showed that the integrated system cover 69,144,399 sites in B. mori genome, and one site could be found in every 6.5 bp. The efficiency and resolution of this CRISPR platform will probably accelerate both fundamental researches and applicable studies in B. mori, and perhaps other insects.
Collapse
Affiliation(s)
- Sanyuan Ma
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China; Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China
| | - Yue Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China
| | - Yuanyuan Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China
| | - Jiasong Chang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China
| | - Tong Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China
| | - Xiaogang Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China
| | - Run Shi
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China
| | - Wei Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China
| | - Xiaojuan Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China; Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716 PR China; Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
| |
Collapse
|
17
|
Panthee S, Paudel A, Hamamoto H, Sekimizu K. Advantages of the Silkworm As an Animal Model for Developing Novel Antimicrobial Agents. Front Microbiol 2017; 8:373. [PMID: 28326075 PMCID: PMC5339274 DOI: 10.3389/fmicb.2017.00373] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/23/2017] [Indexed: 11/13/2022] Open
Abstract
The demand for novel antibiotics to combat the global spread of multi drug-resistant pathogens continues to grow. Pathogenic bacteria and fungi that cause fatal human infections can also kill silkworms and the infected silkworms can be cured by the same antibiotics used to treat infections in the clinic. As an invertebrate model, silkworm model is characterized by its convenience, low cost, no ethical issues. The presence of conserved immune response and similar pharmacokinetics compared to mammals make silkworm infection model suitable to examine the therapeutic effectiveness of antimicrobial agents. Based on this, we utilized silkworm bacterial infection model to screen the therapeutic effectiveness of various microbial culture broths and successfully identified a therapeutically effective novel antibiotic, lysocin E, which has a novel mode of action of binding to menaquinone, thus leading to membrane damage and bactericidal activity. The similar approach to screen potential antibiotics resulted in the identification of other therapeutically effective novel antibiotics, such as nosokomycin and ASP2397 (VL-2397). In this regard, we propose that the silkworm antibiotic screening model is very effective for identifying novel antibiotics. In this review, we summarize the advantages of the silkworm model and propose that the utilization of silkworm infection model will facilitate the discovery of novel therapeutically effective antimicrobial agents.
Collapse
Affiliation(s)
- Suresh Panthee
- Institute of Medical Mycology, Teikyo University Tokyo, Japan
| | - Atmika Paudel
- Institute of Medical Mycology, Teikyo University Tokyo, Japan
| | | | | |
Collapse
|
18
|
Sumitani M, Kondo M, Kasashima K, Endo H, Nakamura K, Misawa T, Tanaka H, Sezutsu H. Characterization of Bombyx mori mitochondrial transcription factor A, a conserved regulator of mitochondrial DNA. Gene 2016; 608:103-113. [PMID: 28027964 DOI: 10.1016/j.gene.2016.12.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 12/20/2016] [Indexed: 01/18/2023]
Abstract
In the present study, we initially cloned and characterized a mitochondrial transcription factor A (Tfam) homologue in the silkworm, Bombyx mori. Bombyx mori TFAM (BmTFAM) localized to mitochondria in cultured silkworm and human cells, and co-localized with mtDNA nucleoids in human HeLa cells. In an immunoprecipitation analysis, BmTFAM was found to associate with human mtDNA in mitochondria, indicating its feature as a non-specific DNA-binding protein. In spite of the low identity between BmTFAM and human TFAM (26.5%), the expression of BmTFAM rescued mtDNA copy number reductions and enlarged mtDNA nucleoids in HeLa cells, which were induced by human Tfam knockdown. Thus, BmTFAM compensates for the function of human TFAM in HeLa cells, demonstrating that the mitochondrial function of TFAM is highly conserved between silkworms and humans. BmTfam mRNA was strongly expressed in early embryos. Through double-stranded RNA (dsRNA)-based RNA interference (RNAi) in silkworm embryos, we found that the knockdown of BmTFAM reduced the amount of mtDNA and induced growth retardation at the larval stage. Collectively, these results demonstrate that BmTFAM is a highly conserved mtDNA regulator and may be a good candidate for investigating and modulating mtDNA metabolism in this model organism.
Collapse
Affiliation(s)
- Megumi Sumitani
- Transgenic Silkworm Research Unit, Division of Biotechnology, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Owashi, Tsukuba 305-8634, Japan.
| | - Mari Kondo
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Chiba, Japan
| | - Katsumi Kasashima
- Division of Functional Biochemistry, Department of Biochemistry, Jichi Medical University, Shimotsuke, Tochigi 329-0498, Japan
| | - Hitoshi Endo
- Division of Functional Biochemistry, Department of Biochemistry, Jichi Medical University, Shimotsuke, Tochigi 329-0498, Japan
| | - Kaoru Nakamura
- Transgenic Silkworm Research Unit, Division of Biotechnology, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Owashi, Tsukuba 305-8634, Japan
| | - Toshihiko Misawa
- Transgenic Silkworm Research Unit, Division of Biotechnology, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Owashi, Tsukuba 305-8634, Japan
| | - Hiromitsu Tanaka
- Insect-Microbe Research Unit, Division of Insect Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Owashi, Tsukuba 305-8634, Japan
| | - Hideki Sezutsu
- Transgenic Silkworm Research Unit, Division of Biotechnology, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Owashi, Tsukuba 305-8634, Japan; Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Chiba, Japan.
| |
Collapse
|