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Bai Y, Lv YN, Zeng M, Yan ZY, Huang DY, Wen JZ, Lu HN, Zhang PY, Wang YF, Ban N, Yuan DW, Li S, Luan YX. E93 is indispensable for reproduction in ametabolous and hemimetabolous insects. Development 2024; 151:dev202518. [PMID: 38646855 DOI: 10.1242/dev.202518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 04/15/2024] [Indexed: 04/23/2024]
Abstract
Ecdysone-induced protein 93 (E93), known as the 'adult-specifier' transcription factor in insects, triggers metamorphosis in both hemimetabolous and holometabolous insects. Although E93 is conserved in ametabolous insects, its spatiotemporal expression and physiological function remain poorly understood. In this study, we first discover that, in the ametabolous firebrat Thermobia domestica, the previtellogenic ovary exhibits cyclically high E93 expression, and E93 mRNA is broadly distributed in previtellogenic ovarioles. E93 homozygous mutant females of T. domestica exhibit severe fecundity deficiency due to impaired previtellogenic development of the ovarian follicles, likely because E93 induces the expression of genes involved in ECM (extracellular matrix)-receptor interactions during previtellogenesis. Moreover, we reveal that in the hemimetabolous cockroach Blattella germanica, E93 similarly promotes previtellogenic ovarian development. In addition, E93 is also essential for vitellogenesis that is necessary to guarantee ovarian maturation and promotes the vitellogenesis-previtellogenesis switch in the fat body of adult female cockroaches. Our findings deepen the understanding of the roles of E93 in controlling reproduction in insects, and of E93 expression and functional evolution, which are proposed to have made crucial contributions to the origin of insect metamorphosis.
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Affiliation(s)
- Yu Bai
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
- Guangmeiyuan R&D Center, Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, South China Normal University, Meizhou 514000, China
| | - Ya-Nan Lv
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Mei Zeng
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Zi-Yu Yan
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Dan-Yan Huang
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Jia-Zhen Wen
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Hu-Na Lu
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Pei-Yan Zhang
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Yi-Fan Wang
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Ning Ban
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Dong-Wei Yuan
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
| | - Sheng Li
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
- Guangmeiyuan R&D Center, Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, South China Normal University, Meizhou 514000, China
| | - Yun-Xia Luan
- Guangdong Provincial Key Laboratory of Insect Development Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510000, China
- Guangmeiyuan R&D Center, Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, South China Normal University, Meizhou 514000, China
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Zhang ZL, Xu QY, Zhang R, Shen C, Bao HB, Luo GH, Fang JC. The irregular developmental duration mainly caused by the broad-complex in Chilo suppressalis. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 204:106090. [PMID: 39277403 DOI: 10.1016/j.pestbp.2024.106090] [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: 06/28/2024] [Revised: 08/04/2024] [Accepted: 08/16/2024] [Indexed: 09/17/2024]
Abstract
Chilo suppressalis, a critical rice stem borer pest, poses significant challenges to rice production due to its overlapping generations and irregular developmental duration. These characteristics complicate pest management strategies. According to the dynamic analysis of the overwintering adults of C. suppressalis in fields, it indicates that the phenomenon of irregular development of C. suppressalis exists widely and continuously. This study delves into the potential role of the Broad-Complex (Br-C) gene in the developmental duration of C. suppressalis. Four isoforms of Br-C, named CsBr-C Z1, CsBr-C Z2, CsBr-C Z4, and CsBr-C Z7, were identified. After CsBr-Cs RNAi, the duration of larva development spans extended obviously. And, the average developmental duration of dsCsBr-Cs feeding individuals increased obviously. Meanwhile, the average developmental duration of the dsCsBr-C Z2 feeding group was the longest among all the RNAi groups. After dsCsBr-Cs feeding continuously, individuals pupated at different instars changed obviously: the proportion of individuals pupated at the 5th instar decreased and pupated at the 7th instar or higher increased significantly. Moreover, the pupation rate of dsCsBr-Cs (except dsCsBr-C Z7) were significantly lower than that of dsGFP. The same results were obtained from the mutagenesis in CsBr-C genes mediated by CRISPR/Cas9. The average developmental duration of CsBr-Cs knockout individuals was significantly prolonged. And, the instar of pupation in knockout individuals was also delayed significantly. In conclusion, this work showed that CsBr-Cs played a crucial role in pupal commitment and affected the developmental duration of C. suppressalis significantly.
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Affiliation(s)
- Zhi-Ling Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Key Laboratory for Food and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
| | - Qing-Yu Xu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Key Laboratory for Food and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
| | - Ru Zhang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Key Laboratory for Food and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
| | - Chen Shen
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Key Laboratory for Food and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
| | - Hai-Bo Bao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Key Laboratory for Food and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China
| | - Guang-Hua Luo
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Key Laboratory for Food and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China.
| | - Ji-Chao Fang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences; Jiangsu Key Laboratory for Food and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China.
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3
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Erezyilmaz D. The genetic determination of alternate stages in polyphenic insects. Evol Dev 2024; 26:e12485. [PMID: 38867484 DOI: 10.1111/ede.12485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/23/2024] [Accepted: 05/14/2024] [Indexed: 06/14/2024]
Abstract
Molt-based transitions in form are a central feature of insect life that have enabled adaptation to diverse and changing environments. The endocrine regulation of these transitions is well established, but an understanding of their genetic regulation has only recently emerged from insect models. The pupal and adult stages of metamorphosing insects are determined by the stage specifying transcription factors broad-complex (br) and Ecdysone inducible protein 93 (E93), respectively. A probable larval determinant, chronologically inappropriate metamorphosis (chinmo), has just recently been characterized. Expression of these three transcription factors in the metamorphosing insects is regulated by juvenile hormone with ecdysteroid hormones, and by mutual repression between the stage-specific transcription factors. This review explores the hypothesis that variations in the onset, duration, and tissue-specific expression of chinmo, br, and E93 underlie other polyphenisms that have arisen throughout insects, including the castes of social insects, aquatic stages of mayflies, and the neoteny of endoparasites. The mechanisms that constrain how chinmo, br, and E93 expression may vary will also constrain the ways that insect life history may evolve. I find that four types of expression changes are associated with novel insect forms: (1) heterochronic shift in the turnover of expression, (2) expansion or contraction of expression, (3) tissue-specific expression, and (4) redeployment of stage-specific expression. While there is more to be learned about chinmo, br, and E93 function in diverse insect taxa, the studies outlined here show that insect stages are modular units in developmental time and a substrate for evolutionary forces to act upon.
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Affiliation(s)
- Deniz Erezyilmaz
- Department of Physiology, Anatomy and Genetics, Centre for Neural Circuits and Behavior, University of Oxford, Oxford, UK
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He Q, Chen S, Hou T, Chen J. Juvenile hormone-induced microRNA miR-iab-8 regulates lipid homeostasis and metamorphosis in Drosophila melanogaster. INSECT MOLECULAR BIOLOGY 2024. [PMID: 39005109 DOI: 10.1111/imb.12944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 07/03/2024] [Indexed: 07/16/2024]
Abstract
Metamorphosis plays an important role in the evolutionary success of insects. Accumulating evidence indicated that microRNAs (miRNAs) are involved in the regulation of processes associated with insect metamorphosis. However, the miRNAs coordinated with juvenile hormone (JH)-regulated metamorphosis remain poorly reported. In the present study, using high-throughput miRNA sequencing combined with Drosophila genetic approaches, we demonstrated that miR-iab-8, which primarily targets homeotic genes to modulate haltere-wing transformation and sterility was up-regulated by JH and involved in JH-mediated metamorphosis. Overexpression of miR-iab-8 in the fat body resulted in delayed development and failure of larval-pupal transition. Furthermore, metabolomic analysis results revealed that overexpression of miR-iab-8 caused severe energy metabolism defects especially the lipid metabolism, resulting in significantly reduced triacylglycerol (TG) content and glycerophospholipids but enhanced accumulation of phosphatidylcholine (PC) and phosphatidylethanolamine (PE). In line with this, Nile red staining demonstrated that during the third larval development, the TG content in the miR-iab-8 overexpression larvae was continuously decreased, which is opposite to the control. Additionally, the transcription levels of genes committed to TG synthesis and breakdown were found to be significantly increased and the expression of genes responsible for glycerophospholipids metabolism were also altered. Overall, we proposed that JH induced miR-iab-8 expression to perturb the lipid metabolism homeostasis especially the TG storage in the fat body, which in turn affected larval growth and metamorphosis.
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Affiliation(s)
- Qianyu He
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Shanshan Chen
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Tianlan Hou
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Jinxia Chen
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
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Wang HC, Li L, Zhang JH, Yao ZH, Pang BP. MicroRNA miR-285 modulates the metamorphosis in Galeruca daurica by targeting Br-C. PEST MANAGEMENT SCIENCE 2024; 80:3349-3357. [PMID: 38385645 DOI: 10.1002/ps.8038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/20/2023] [Accepted: 02/20/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND Galeruca daurica has become a new pest on the Inner Mongolia grasslands since an abrupt outbreak in 2009 caused serious damage. As a pupa indicator during insect metamorphosis, the early response gene of the ecdysone signaling pathway, Broad-Complex (Br-C), plays a vital role in the growth and development of insects. MicroRNAs (miRNAs) are small non-coding RNAs which mediate various biological activities, but it is unknown whether and how Br-C is regulated by miRNAs. RESULTS Temporal expression profiles revealed that miR-285 and Br-C basically displayed an opposite trend during larval-adult development, and Br-C was sharply up-regulated on the last day of final-instar larvae while miR-285 was significantly down-regulated. Both dual-luciferase reporter assay and miRNA-mRNA interaction assay indicated that miR-285 interacts with the coding sequence of Br-C and represses its expression. Not only overexpression but also downexpression of miR-285 led to the failure of larval to pupal to adult metamorphosis. In addition, both overexpression of miR-285 and silence of Br-C inhibited the expression of Br-C and other ecdysone signaling pathway genes, including E74, E75, ECR, FTZ-F1, and HR3. On the contrary, suppressing miR-285 obtained opposite results. Further experiments showed that 20-hydroxyecdysone down-regulated miR-285 and up-regulated Br-C and above-mentioned genes, whereas juvenile hormone alalogue (JHA) resulted in opposite effects. CONCLUSION Our results reveal that miR-285 is involved in mediating the metamorphosis in G. daurica by targeting Br-C in the ecdysone signaling pathway. miR-285 and its target Br-C could be as a potential target for G. daurica management. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Hai-Chao Wang
- Research Center for Grassland Entomology, Inner Mongolia Agricultural University, Hohhot, China
| | - Ling Li
- Research Center for Grassland Entomology, Inner Mongolia Agricultural University, Hohhot, China
| | - Jing-Hang Zhang
- Inner Mongolia Center for Plant Protection and Quarantine, Hohhot, China
| | - Zhi-Han Yao
- Research Center for Grassland Entomology, Inner Mongolia Agricultural University, Hohhot, China
| | - Bao-Ping Pang
- Research Center for Grassland Entomology, Inner Mongolia Agricultural University, Hohhot, China
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6
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Wang HC, Li L, Zhang JH, Yao ZH, Pang BP. MicroRNA miR-7-5p targets MARK2 to control metamorphosis in Galeruca daurica. Comp Biochem Physiol B Biochem Mol Biol 2024; 272:110967. [PMID: 38521445 DOI: 10.1016/j.cbpb.2024.110967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/20/2024] [Accepted: 03/20/2024] [Indexed: 03/25/2024]
Abstract
The MARK2 gene, coding microtubule affinity-regulating kinase or serine/threonine protein kinase, is an important modulator in organism microtubule generation and cell polarity. However, its role in the metamorphosis of insects remains unknown. In this study, we found a conserved miRNA, miR-7-5p, which targets MARK2 to participate in the regulation of the larval-pupal metamorphosis in Galeruca daurica. The dual luciferase reporter assay showed that miR-7-5p interacted with the 3' UTR of MARK2 and repressed its expression. The expression profiling of miR-7-5p and MARK2 displayed an opposite trend during the larval-adult development process. In in-vivo experiments, overexpression of miR-7-5p by injecting miR-7-5p agomir in the final instar larvae down-regulated MARK2 and up-regulated main ecdysone signaling pathway genes including E74, E75, ECR, FTZ-F1 and HR3, which was similar to the results from knockdown of MARK2 by RNAi. In contrast, repression of miR-7-5p by injecting miR-7-5p antagomir obtained opposite effects. Notably, both overexpression and repression of miR-7-5p in the final instar larvae caused abnormal molting and high mortality during the larval-pupal transition, and high mortality during the pupal-adult transition. The 20-hydroxyecdysone (20E) injection experiment showed that 20E up-regulated miR-7-5p whereas down-regulated MARK2. This study reveals that the accurate regulation of miRNAs and their target genes is indispensable for insect metamorphosis.
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Affiliation(s)
- Hai-Chao Wang
- Research Center for Grassland Entomology, Inner Mongolia Agricultural University, Hohhot, China
| | - Ling Li
- Research Center for Grassland Entomology, Inner Mongolia Agricultural University, Hohhot, China
| | - Jing-Hang Zhang
- Inner Mongolia Center for Plant Protection and Quarantine, Hohhot, China
| | - Zhi-Han Yao
- Research Center for Grassland Entomology, Inner Mongolia Agricultural University, Hohhot, China
| | - Bao-Ping Pang
- Research Center for Grassland Entomology, Inner Mongolia Agricultural University, Hohhot, China.
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Anjum AA, Lin MJ, Jin L, Li GQ. A critical role for the nuclear protein Akirin in larval development in Henosepilachna vigintioctopunctata. INSECT MOLECULAR BIOLOGY 2024. [PMID: 38783592 DOI: 10.1111/imb.12929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 05/04/2024] [Indexed: 05/25/2024]
Abstract
Akirin is a nuclear protein that controls development in vertebrates and invertebrates. The function of Akirin has not been assessed in any Coleopteran insects. We found that high levels of akirin transcripts in Henosepilachna vigintioctopunctata, a serious Coleopteran potato defoliator (hereafter Hvakirin), were present at prepupal, pupal and adult stages, especially in larval foregut and fat body. RNA interference (RNAi) targeting Hvakirin impaired larval development. The Hvakirin RNAi larvae arrested development at the final larval instar stage. They remained as stunted larvae, gradually blackened and finally died. Moreover, the remodelling of gut and fat body was inhibited in the Hvakirin depleted larvae. Two layers of cuticles, old and newly formed, were noted in the dsegfp-injected animals. In contrast, only a layer of cuticle was found in the dsakirin-injected beetles, indicating the arrest of larval development. Furthermore, the expression of three transforming growth factor-β cascade genes (Hvsmox, Hvmyo and Hvbabo), a 20-hydroxyecdysone (20E) receptor gene (HvEcR) and six 20E response genes (HvHR3, HvHR4, HvE75, HvBrC, HvE93 and Hvftz-f1) was significantly repressed, consistent with decreased 20E signalling. Conversely, the transcription of a juvenile hormone (JH) biosynthesis gene (Hvjhamt), a JH receptor gene (HvMet) and two JH response genes (HvKr-h1 and HvHairy) was greatly enhanced. Our findings suggest a critical role of Akirin in larval development in H. vigintioctopunctata.
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Affiliation(s)
- Ahmad Ali Anjum
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Meng-Jiao Lin
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Lin Jin
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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8
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Khong H, Hattley KB, Suzuki Y. The BTB transcription factor, Abrupt, acts cooperatively with Chronologically inappropriate morphogenesis (Chinmo) to repress metamorphosis and promotes leg regeneration. Dev Biol 2024; 509:70-84. [PMID: 38373692 DOI: 10.1016/j.ydbio.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 02/21/2024]
Abstract
Many insects undergo the process of metamorphosis when larval precursor cells begin to differentiate to create the adult body. The larval precursor cells retain stem cell-like properties and contribute to the regenerative ability of larval appendages. Here we demonstrate that two Broad-complex/Tramtrack/Bric-à-brac Zinc-finger (BTB) domain transcription factors, Chronologically inappropriate morphogenesis (Chinmo) and Abrupt (Ab), act cooperatively to repress metamorphosis in the flour beetle, Tribolium castaneum. Knockdown of chinmo led to precocious development of pupal legs and antennae. We show that although topical application of juvenile hormone (JH) prevents the decrease in chinmo expression in the final instar, chinmo and JH act in distinct pathways. Another gene encoding the BTB domain transcription factor, Ab, was also necessary for the suppression of broad (br) expression in T. castaneum in a chinmo RNAi background, and simultaneous knockdown of ab and chinmo led to the precocious onset of metamorphosis. Furthermore, knockdown of ab led to the loss of regenerative potential of larval legs independently of br. In contrast, chinmo knockdown larvae exhibited pupal leg regeneration when a larval leg was ablated. Taken together, our results show that both ab and chinmo are necessary for the maintenance of the larval tissue identity and, apart from its role in repressing br, ab acts as a crucial regulator of larval leg regeneration. Our findings indicate that BTB domain proteins interact in a complex manner to regulate larval and pupal tissue homeostasis.
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Affiliation(s)
- Hesper Khong
- Department of Biological Sciences, Wellesley College, 106 Central St., Wellesley, MA, 02481, USA
| | - Kayli B Hattley
- Department of Biological Sciences, Wellesley College, 106 Central St., Wellesley, MA, 02481, USA
| | - Yuichiro Suzuki
- Department of Biological Sciences, Wellesley College, 106 Central St., Wellesley, MA, 02481, USA.
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Truman JW, Riddiford LM, Konopova B, Nouzova M, Noriega FG, Herko M. The embryonic role of juvenile hormone in the firebrat, Thermobia domestica, reveals its function before its involvement in metamorphosis. eLife 2024; 12:RP92643. [PMID: 38568859 PMCID: PMC10994664 DOI: 10.7554/elife.92643] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024] Open
Abstract
To gain insights into how juvenile hormone (JH) came to regulate insect metamorphosis, we studied its function in the ametabolous firebrat, Thermobia domestica. Highest levels of JH occur during late embryogenesis, with only low levels thereafter. Loss-of-function and gain-of-function experiments show that JH acts on embryonic tissues to suppress morphogenesis and cell determination and to promote their terminal differentiation. Similar embryonic actions of JH on hemimetabolous insects with short germ band embryos indicate that JH's embryonic role preceded its derived function as the postembryonic regulator of metamorphosis. The postembryonic expansion of JH function likely followed the evolution of flight. Archaic flying insects were considered to lack metamorphosis because tiny, movable wings were evident on the thoraces of young juveniles and their positive allometric growth eventually allowed them to support flight in late juveniles. Like in Thermobia, we assume that these juveniles lacked JH. However, a postembryonic reappearance of JH during wing morphogenesis in the young juvenile likely redirected wing development to make a wing pad rather than a wing. Maintenance of JH then allowed wing pad growth and its disappearance in the mature juvenile then allowed wing differentiation. Subsequent modification of JH action for hemi- and holometabolous lifestyles are discussed.
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Affiliation(s)
- James W Truman
- Friday Harbor Laboratories, University of WashingtonFriday HarborUnited States
- Department of Biology, University of WashingtonSeattleUnited States
| | - Lynn M Riddiford
- Friday Harbor Laboratories, University of WashingtonFriday HarborUnited States
- Department of Biology, University of WashingtonSeattleUnited States
| | - Barbora Konopova
- Department of Zoology, Faculty of Science, University of South BohemiaCeske BudejoviceCzech Republic
- Institute of Entomology, Biology Centre of the Czech Academy of SciencesCeske BudejoviceCzech Republic
| | - Marcela Nouzova
- Institute of Parasitology, Biology Centre of the Czech Academy of SciencesCeske BudejoviceCzech Republic
| | - Fernando G Noriega
- Department of Biological Sciences and BSI, Florida International UniversityMiamiUnited States
- Department of Parasitology, Faculty of Science, University of South BohemiaCeské BudejoviceCzech Republic
| | - Michelle Herko
- Friday Harbor Laboratories, University of WashingtonFriday HarborUnited States
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10
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Ge F, Yu Q, Zhang J, Han Y, Zhu D, Xie X. E93 gene in the swimming crab, Portunus trituberculatus: Responsiveness to 20-hydroxyecdysone and methyl farnesoate and role on regulating ecdysteroid synthesis. Comp Biochem Physiol B Biochem Mol Biol 2024; 270:110910. [PMID: 38193341 DOI: 10.1016/j.cbpb.2023.110910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 01/10/2024]
Abstract
Ecdysone-induced protein 93 (E93) is a metamorphic determinant involved in crosstalk between 20-hydroxyecdysone (20E) and juvenile hormone (JH) during the insect molting process. The present study identified the E93 gene from the swimming crab, P. trituberculatus, and found it was widely distributed in adult tissues. PtE93 mRNA levels in Y-organ and epidermis fluctuated during the molt cycle, suggesting its involvement in juvenile molting. In vitro and in vivo treatments with 20E led to an induction of PtE93 expression in Y-organ and epidermis, while we found the opposite effect for methyl farnesoate (MF) treatments, a crustacean equivalent of insect JH. We also observed that two genes for ecdysteroid biosynthesis, Spook (Spo) and Shadow (Sad), were suppressed by 20E and induced by MF, showing a negative correlation between PtE93 and ecdysteroid biosynthesis. PtE93 RNA interference (RNAi) induced Spo and Sad expression levels, elevated ecdysteroid content in culture medium, and relieved the 20E inhibitory effect on ecdysteroid synthesis, indicating an inhibitory role of PtE93 on ecdysteroid synthesis. Overall, our results suggest that E93 may be involved in the crosstalk between 20E and MF during crustacean molting, and its presence in Y-organ is closely related to ecdysteroid synthesis.
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Affiliation(s)
- Fuqiang Ge
- Key Laboratory of Aquacultural Biotechnology Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, China
| | - Qiaoling Yu
- Key Laboratory of Aquacultural Biotechnology Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, China
| | - Jun Zhang
- Key Laboratory of Aquacultural Biotechnology Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, China
| | - Yaoyao Han
- Key Laboratory of Aquacultural Biotechnology Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, China
| | - Dongfa Zhu
- Key Laboratory of Aquacultural Biotechnology Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, China.
| | - Xi Xie
- Key Laboratory of Aquacultural Biotechnology Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, China.
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11
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Morrow H, Mirth CK. Timing Drosophila development through steroid hormone action. Curr Opin Genet Dev 2024; 84:102148. [PMID: 38271845 DOI: 10.1016/j.gde.2023.102148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/15/2023] [Accepted: 12/15/2023] [Indexed: 01/27/2024]
Abstract
Specifically timed pulses of the moulting hormone ecdysone are necessary for developmental progression in insects, guiding development through important milestones such as larval moults, pupation and metamorphosis. It also coordinates the acquisition of cell identities, known as cell patterning, and growth in a tissue-specific manner. In the absence of ecdysone, the ecdysone receptor heterodimer Ecdysone Receptor and Ultraspiracle represses expression of target primary response genes, which become de-repressed as the ecdysone titre rises. However, ecdysone signalling elicits both repressive and activating responses in a temporal and tissue-specific manner. To understand how ecdysone achieves such specificity, this review explores the layers of gene regulation involved in stage-appropriate ecdysone responses in Drosophila fruit flies.
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Affiliation(s)
- Hannah Morrow
- School of Biological Sciences, Monash University, Clayton, Victoria 3000, Australia.
| | - Christen K Mirth
- School of Biological Sciences, Monash University, Clayton, Victoria 3000, Australia
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12
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Truman JW, Riddiford LM, Konopová B, Nouzova M, Noriega FG, Herko M. The embryonic role of juvenile hormone in the firebrat, Thermobia domestica, reveals its function before its involvement in metamorphosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.06.561279. [PMID: 37873170 PMCID: PMC10592639 DOI: 10.1101/2023.10.06.561279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
To gain insights into how juvenile hormone (JH) came to regulate insect metamorphosis, we studied its function in the ametabolous firebrat, Thermobia domestica. Highest levels of JH occur during late embryogenesis, with only low levels thereafter. Loss-of-function and gain-of-function experiments show that JH acts on embryonic tissues to suppress morphogenesis and cell determination and to promote their terminal differentiation. Similar embryonic actions of JH on hemimetabolous insects with short germ band embryos indicate that JH's embryonic role preceded its derived function as the postembryonic regulator of metamorphosis. The postembryonic expansion of JH function likely followed the evolution of flight. Archaic flying insects were considered to lack metamorphosis because tiny, movable wings were evident on the thoraces of young juveniles and their positive allometric growth eventually allowed them to support flight in late juveniles. Like in Thermobia, we assume that these juveniles lacked JH. However, a postembryonic reappearance of JH during wing morphogenesis in the young juvenile likely redirected wing development to make a wing pad rather than a wing. Maintenance of JH then allowed wing pad growth and its disappearance in the mature juvenile then allowed wing differentiation. Subsequent modification of JH action for hemi- and holometabolous lifestyles are discussed.
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Affiliation(s)
- James W. Truman
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, USA
- Department of Biology, University of Washington, Seattle, WA USA
| | - Lynn M. Riddiford
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, USA
- Department of Biology, University of Washington, Seattle, WA USA
| | - Barbora Konopová
- Department of Zoology, Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
- Institute of Entomology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Marcela Nouzova
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Fernando G. Noriega
- Department of Biological Sciences and BSI, Florida International University, FL ,USA
- Department of Parasitology, Faculty of Science, University of South Bohemia, Ceské Budejovice, Czech Republic
| | - Michelle Herko
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, USA
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13
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Zhang S, Wu S, Yao R, Wei X, Ohlstein B, Guo Z. Eclosion muscles secrete ecdysteroids to initiate asymmetric intestinal stem cell division in Drosophila. Dev Cell 2024; 59:125-140.e12. [PMID: 38096823 DOI: 10.1016/j.devcel.2023.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/05/2023] [Accepted: 11/14/2023] [Indexed: 01/11/2024]
Abstract
During organ development, tissue stem cells first expand via symmetric divisions and then switch to asymmetric divisions to minimize the time to obtain a mature tissue. In the Drosophila midgut, intestinal stem cells switch their divisions from symmetric to asymmetric at midpupal development to produce enteroendocrine cells. However, the signals that initiate this switch are unknown. Here, we identify the signal as ecdysteroids. In the presence of ecdysone, EcR and Usp promote the expression of E93 to suppress Br expression, resulting in asymmetric divisions. Surprisingly, the primary source of pupal ecdysone is not from the prothoracic gland but from dorsal internal oblique muscles (DIOMs), a group of transient skeletal muscles that are required for eclosion. Genetic analysis shows that DIOMs secrete ecdysteroids during mTOR-mediated muscle remodeling. Our findings identify sequential endocrine and mechanical roles for skeletal muscle, which ensure the timely asymmetric divisions of intestinal stem cells.
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Affiliation(s)
- Song Zhang
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Song Wu
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Ruining Yao
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xueying Wei
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Benjamin Ohlstein
- Children's Research Institute and Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Zheng Guo
- Department of Medical Genetics, School of Basic Medicine, Institute for Brain Research, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; Cell Architecture Research Center, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China.
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14
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Liu F, Yu S, Chen N, Ren C, Li S. Nutrition- and hormone-controlled developmental plasticity in Blattodea. CURRENT OPINION IN INSECT SCIENCE 2023; 60:101128. [PMID: 37806339 DOI: 10.1016/j.cois.2023.101128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 09/12/2023] [Accepted: 10/02/2023] [Indexed: 10/10/2023]
Abstract
Blattodea, which includes cockroaches and termites, possesses high developmental plasticity that is mainly controlled by nutritional conditions and insect hormones. Insulin/insulin-like growth factor signaling (IIS), target of rapamycin complex 1 (TORC1), and adenosine monophosphate-activated protein complex are the three primary nutrition-responsive signals. Juvenile hormone (JH) and 20-hydroxyecdysone (20E) constitute the two most vital insect hormones that might interact with each other through the Met, Kr-h1, E93 (MEKRE93) pathway. Nutritional and hormonal signals interconnect to create a complex regulatory network. Here we summarize recent progress in our understanding of how nutritional and hormonal signals coordinately control the developmental plasticity of metamorphosis, reproduction, and appendage regeneration in cockroaches as well as caste differentiation in termites. We also highlight several perspectives that should be further emphasized in the studies of developmental plasticity in Blattodea. This review provides a general landscape in the field of nutrition- and hormone-controlled developmental plasticity in insects.
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Affiliation(s)
- Fangfang Liu
- 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 510631, China; Guangmeiyuan R&D Center, Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, South China Normal University, Meizhou 514779, China
| | - Shuxin Yu
- 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 510631, China
| | - Nan Chen
- 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 510631, China
| | - Chonghua Ren
- 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 510631, China
| | - Sheng Li
- 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 510631, China; Guangmeiyuan R&D Center, Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, South China Normal University, Meizhou 514779, China.
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15
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Asano F, Miyahara T, Miyamoto H, Kodama H. A Thermophile-Fermented Compost Modulates Intestinal Cations and the Expression of a Juvenile Hormone-Binding Protein Gene in the Female Larvae of Hercules Beetle Dynastes hercules (Coleoptera: Scarabaeidae). INSECTS 2023; 14:910. [PMID: 38132584 PMCID: PMC10744137 DOI: 10.3390/insects14120910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/24/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023]
Abstract
The Hercules beetle larvae grow by feeding on humus, and adding a thermophile-fermented compost to the humus can upregulate the growth of female larvae. In this study, the effects of compost on the intestinal environment, including pH, cation concentrations, and organic acid concentrations of intestinal fluids, were investigated, and the RNA profile of the fat body was determined. Although the total intestinal potassium ions were similar between the larvae grown without compost (control larvae) and those with compost (compost larvae), the proportion of potassium ions in the midgut of the compost larvae drastically increased. In the midgut, an unidentified organic acid was the most abundant, and its concentration increased in the compost larvae. Transcriptome analysis showed that a gene encoding hemolymph juvenile-binding protein (JHBP) was expressed in the compost female larvae and not in the control female larvae. Expression of many genes involved in the defensive system was decreased in the compost female larvae. These results suggest that the female-specific enhancement of larval growth by compost was associated with the increased JHBP expression under conditions in which the availability of nutrition from the humus was improved by an increase in potassium ions in the midgut.
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Affiliation(s)
| | | | | | - Hiroaki Kodama
- Graduate School of Horticulture, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; (F.A.); (T.M.); (H.M.)
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16
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Chafino S, Salvia R, Cruz J, Martín D, Franch-Marro X. TGFß/activin-dependent activation of Torso controls the timing of the metamorphic transition in the red flour beetle Tribolium castaneum. PLoS Genet 2023; 19:e1010897. [PMID: 38011268 PMCID: PMC10703416 DOI: 10.1371/journal.pgen.1010897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/07/2023] [Accepted: 11/10/2023] [Indexed: 11/29/2023] Open
Abstract
Understanding the mechanisms governing body size attainment during animal development is of paramount importance in biology. In insects, a crucial phase in determining body size occurs at the larva-pupa transition, marking the end of the larval growth period. Central to this process is the attainment of the threshold size (TS), a critical developmental checkpoint that must be reached before the larva can undergo metamorphosis. However, the intricate molecular mechanisms by which the TS orchestrates this transition remain poor understood. In this study, we investigate the role of the interaction between the Torso and TGFß/activin signaling pathways in regulating metamorphic timing in the red flour beetle, Tribolium castaneum. Our results show that Torso signaling is required specifically during the last larval instar and that its activation is mediated not only by the prothoracicotropic hormone (Tc-Ptth) but also by Trunk (Tc-Trk), another ligand of the Tc-Torso receptor. Interestingly, we show that while Tc-Torso activation by Tc-Ptth determines the onset of metamorphosis, Tc-Trk promotes growth during the last larval stage. In addition, we found that the expression of Tc-torso correlates with the attainment of the TS and the decay of juvenile hormone (JH) levels, at the onset of the last larval instar. Notably, our data reveal that activation of TGFß/activin signaling pathway at the TS is responsible for repressing the JH synthesis and inducing Tc-torso expression, initiating metamorphosis. Altogether, these findings shed light on the pivotal involvement of the Ptth/Trunk/Torso and TGFß/activin signaling pathways as critical regulatory components orchestrating the TS-driven metamorphic initiation, offering valuable insights into the mechanisms underlying body size determination in insects.
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Affiliation(s)
- Sílvia Chafino
- Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | - Roser Salvia
- Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | - Josefa Cruz
- Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | - David Martín
- Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | - Xavier Franch-Marro
- Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
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17
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Truman JW, Riddiford LM. Drosophila postembryonic nervous system development: a model for the endocrine control of development. Genetics 2023; 223:iyac184. [PMID: 36645270 PMCID: PMC9991519 DOI: 10.1093/genetics/iyac184] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/13/2022] [Indexed: 01/17/2023] Open
Abstract
During postembryonic life, hormones, including ecdysteroids, juvenile hormones, insulin-like peptides, and activin/TGFβ ligands act to transform the larval nervous system into an adult version, which is a fine-grained mosaic of recycled larval neurons and adult-specific neurons. Hormones provide both instructional signals that make cells competent to undergo developmental change and timing cues to evoke these changes across the nervous system. While touching on all the above hormones, our emphasis is on the ecdysteroids, ecdysone and 20-hydroxyecdysone (20E). These are the prime movers of insect molting and metamorphosis and are involved in all phases of nervous system development, including neurogenesis, pruning, arbor outgrowth, and cell death. Ecdysteroids appear as a series of steroid peaks that coordinate the larval molts and the different phases of metamorphosis. Each peak directs a stereotyped cascade of transcription factor expression. The cascade components then direct temporal programs of effector gene expression, but the latter vary markedly according to tissue and life stage. The neurons read the ecdysteroid titer through various isoforms of the ecdysone receptor, a nuclear hormone receptor. For example, at metamorphosis the pruning of larval neurons is mediated through the B isoforms, which have strong activation functions, whereas subsequent outgrowth is mediated through the A isoform through which ecdysteroids play a permissive role to allow local tissue interactions to direct outgrowth. The major circulating ecdysteroid can also change through development. During adult development ecdysone promotes early adult patterning and differentiation while its metabolite, 20E, later evokes terminal adult differentiation.
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Affiliation(s)
- James W Truman
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
| | - Lynn M Riddiford
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
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18
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Zhu GH, Gaddelapati SC, Jiao Y, Koo J, Palli SR. CRISPR-Cas9 Genome Editing Uncovers the Mode of Action of Methoprene in the Yellow Fever Mosquito, Aedes aegypti. CRISPR J 2022; 5:813-824. [PMID: 36374965 PMCID: PMC9805843 DOI: 10.1089/crispr.2022.0066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Methoprene, a juvenile hormone (JH) analog, is widely used for insect control, but its mode of action is not known. To study methoprene action in the yellow fever mosquito, Aedes aegypti, the E93 (ecdysone-induced transcription factor) was knocked out using the CRISPR-Cas9 system. The E93 mutant pupae retained larval tissues similar to methoprene-treated insects. These insects completed pupal ecdysis and died as pupa. In addition, the expression of transcription factors, broad complex and Krüppel homolog 1 (Kr-h1), increased and that of programmed cell death (PCD) and autophagy genes decreased in E93 mutants. These data suggest that methoprene functions through JH receptor, methoprene-tolerant, and induces the expression of Kr-h1, which suppresses the expression of E93, resulting in a block in PCD and autophagy of larval tissues. Failure in the elimination of larval tissues and the formation of adult structures results in their death. These results answered long-standing questions on the mode of action of methoprene.
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Affiliation(s)
- Guan-Heng Zhu
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, Kentucky, USA
| | - Sharath Chandra Gaddelapati
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, Kentucky, USA
| | - Yaoyu Jiao
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, Kentucky, USA
| | - Jinmo Koo
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, Kentucky, USA
| | - Subba Reddy Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, Kentucky, USA.,Address correspondence to: Subba Reddy Palli, Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA.
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19
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Jiao Y, Palli SR. Mitochondria dysfunction impairs Tribolium castaneum wing development during metamorphosis. Commun Biol 2022; 5:1252. [PMID: 36380075 PMCID: PMC9666433 DOI: 10.1038/s42003-022-04185-z] [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: 06/28/2022] [Accepted: 10/28/2022] [Indexed: 11/16/2022] Open
Abstract
The disproportionate growth of insect appendages such as facultative growth of wings and exaggeration of beetle horns are examples of phenotypic plasticity. Insect metamorphosis is the critical stage for development of pupal and adult structures and degeneration of the larval cells. How the disproportionate growth of external appendages is regulated during tissue remodeling remains unanswered. Tribolium castaneum is used as a model to study the function of mitochondria in metamorphosis. Mitochondrial dysfunction is achieved by the knockdown of key mitochondrial regulators. Here we show that mitochondrial function is not required for metamorphosis except that severe mitochondrial dysfunction blocks ecdysis. Surprisingly, various abnormal wing growth, including short and wingless phenotypes, are induced after knocking down mitochondrial regulators. Mitochondrial activity is regulated by IIS (insulin/insulin-like growth factor signaling)/FOXO (forkhead box, sub-group O) pathway through TFAM (transcription factor A, mitochondrial). RNA sequencing and differential gene expression analysis show that wing-patterning and insect hormone response genes are downregulated, while programmed cell death and immune response genes are upregulated in insect wing discs with mitochondrial dysfunction. These studies reveal that mitochondria play critical roles in regulating insect wing growth by targeting wing development during metamorphosis, thus showing a novel molecular mechanism underlying developmental plasticity.
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Affiliation(s)
- Yaoyu Jiao
- grid.266539.d0000 0004 1936 8438Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546 USA
| | - Subba Reddy Palli
- grid.266539.d0000 0004 1936 8438Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546 USA
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20
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Knockdown of Ecdysone-Induced Protein 93F Causes Abnormal Pupae and Adults in the Eggplant Lady Beetle. BIOLOGY 2022; 11:biology11111640. [DOI: 10.3390/biology11111640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/02/2022] [Accepted: 11/02/2022] [Indexed: 11/12/2022]
Abstract
Ecdysone-induced protein 93F (E93) plays triple roles during post-embryonic development in insects whose juvenile instars are more than four. However, it only acts as a specifier of adult structures in Drosophila flies whose larval instars are fixed at three. In this study, we determined the functions of E93 in the eggplant lady beetle (Henosepilachna vigintioctopunctata), which has four larval instars. We uncovered that E93 was abundantly expressed at the prepupal and pupal stages. A precocious inhibition of the juvenile hormone signal by RNA interference (RNAi) of HvKr-h1 or HvHairy, two vital downstream developmental effectors, at the penultimate instar larval stage increased the expression of E93, Conversely, ingestion of JH by the third-instar larvae stimulated the expression of HvKr-h1 but repressed the transcription of either HvE93X1 or HvE93X2. However, disturbance of the JH signal neither drove premature metamorphosis nor caused supernumerary instars. In contrast, depletion of E93 at the third- and fourth-instar larval and prepupal stages severely impaired pupation and caused a larval-pupal mixed phenotype: pupal spines and larval scoli were simultaneously presented on the cuticle. RNAi of E93 at the pupal stage affected adult eclosion. When the beetles had suffered from a dsE93 injection at the fourth-instar larval and pupal stages, a few resultant adults emerged, with separated elytra, abnormally folded hindwings, a small body size and short appendages. Taken together, our results suggest the larval instars are fixed in H. vigintioctopunctata; E93 serves as a repressor of larval characters and a specifier of adult structures during the larval–pupal–adult transition.
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21
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Klingler M, Bucher G. The red flour beetle T. castaneum: elaborate genetic toolkit and unbiased large scale RNAi screening to study insect biology and evolution. EvoDevo 2022; 13:14. [PMID: 35854352 PMCID: PMC9295526 DOI: 10.1186/s13227-022-00201-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 07/05/2022] [Indexed: 11/16/2022] Open
Abstract
The red flour beetle Tribolium castaneum has emerged as an important insect model system for a variety of topics. With respect to studying gene function, it is second only to the vinegar fly D. melanogaster. The RNAi response in T. castaneum is exceptionally strong and systemic, and it appears to target all cell types and processes. Uniquely for emerging model organisms, T. castaneum offers the opportunity of performing time- and cost-efficient large-scale RNAi screening, based on commercially available dsRNAs targeting all genes, which are simply injected into the body cavity. Well established transgenic and genome editing approaches are met by ease of husbandry and a relatively short generation time. Consequently, a number of transgenic tools like UAS/Gal4, Cre/Lox, imaging lines and enhancer trap lines are already available. T. castaneum has been a genetic experimental system for decades and now has become a workhorse for molecular and reverse genetics as well as in vivo imaging. Many aspects of development and general biology are more insect-typical in this beetle compared to D. melanogaster. Thus, studying beetle orthologs of well-described fly genes has allowed macro-evolutionary comparisons in developmental processes such as axis formation, body segmentation, and appendage, head and brain development. Transgenic approaches have opened new ways for in vivo imaging. Moreover, this emerging model system is the first choice for research on processes that are not represented in the fly, or are difficult to study there, e.g. extraembryonic tissues, cryptonephridial organs, stink gland function, or dsRNA-based pesticides.
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Affiliation(s)
- Martin Klingler
- Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstr. 5, 91058, Erlangen, Germany.
| | - Gregor Bucher
- Johann-Friedrich-Blumenbach-Institut, GZMB, University of Göttingen, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany.
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22
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Chinmo is the larval member of the molecular trinity that directs Drosophila metamorphosis. Proc Natl Acad Sci U S A 2022; 119:e2201071119. [PMID: 35377802 PMCID: PMC9169713 DOI: 10.1073/pnas.2201071119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The genome of insects with complete metamorphosis contains the instructions for making three distinct body forms, that of the larva, of the pupa, and of the adult. However, the molecular mechanisms by which each gene set is called forth and stably expressed are poorly understood. A half century ago, it was proposed that there was a set of three master genes that inhibited each other’s expression and enabled the expression of genes for each respective stage. We show that the transcription factor chinmo is essential for maintaining the larval stage in Drosophila, and with two other regulatory genes, broad and E93, makes up the trinity of mutually repressive master genes that underlie insect metamorphosis. The molecular control of insect metamorphosis from larva to pupa to adult has long been a mystery. The Broad and E93 transcription factors, which can modify chromatin domains, are known to direct the production of the pupa and the adult, respectively. We now show that chinmo, a gene related to broad, is essential for the repression of these metamorphic genes. Chinmo is strongly expressed during the formation and growth of the larva and its removal results in the precocious expression of broad and E93 in the first stage larva, causing a shift from larval to premetamorphic functions. This trinity of Chinmo, Broad, and E93 regulatory factors is mutually inhibitory. The interaction of this network with regulatory hormones likely ensures the orderly progression through insect metamorphosis.
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23
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Liu XJ, Jun G, Liang XY, Zhang XY, Zhang TT, Liu WM, Zhang JZ, Zhang M. Silencing of transcription factor E93 inhibits adult morphogenesis and disrupts cuticle, wing and ovary development in Locusta migratoria. INSECT SCIENCE 2022; 29:333-343. [PMID: 34117716 DOI: 10.1111/1744-7917.12924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/21/2021] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
Ecdysone-induced protein 93F (E93) plays important roles during the metamorphosis process in insects. In this study, a cDNA of the LmE93 gene was identified from the transcriptome of Locusta migratoria, which consists of the 3378-nucleotide open-reading frame (ORF) and encodes 1125 amino acids with helix-turn-helix (HTH) motifs. Reverse transcription quantitative polymerase chain reaction analysis revealed that LmE93 was highest expressed in ovary. The LmE93 expression level was markedly low from the 3rd to 4th instar nymphs, and greatly increased in 1-day-old 5th instar nymphs with a peak on middle nymphal days, then declined in the late nymphal days. Moreover, injected dsLmE93 into 4th and 5th instar nymphs greatly reduced LmE93 transcripts, respectively, and prevented the process of metamorphosis, causing supernumerary nymphal stages. Hematoxylin-eosin staining of the integument showed that the apolysis occurred in advance in 4th instar nymphs, and old cuticle degradation was decreased in dsLmE93-injected locusts of 5th instar nymphs. Smaller and no fully developed wings with reduced columns between the anterior and posterior regions were found in N6 and N7 supernumerary nymphs. In addition, the development of the ovary in dsLmE93-injected locusts was severely blocked, the yolk was almost not formed and there was no development of ovarioles. The results indicated that LmE93 play key roles in the metamorphosis, cuticle, wing and ovarian development of locusts.
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Affiliation(s)
- Xiao-Jian Liu
- Research Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Guo Jun
- Research Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Xiao-Yu Liang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Xue-Yao Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Ting-Ting Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Wei-Min Liu
- Research Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Jian-Zhen Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Min Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, China
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Juvenile hormone-induced histone deacetylase 3 suppresses apoptosis to maintain larval midgut in the yellow fever mosquito. Proc Natl Acad Sci U S A 2022; 119:e2118871119. [PMID: 35259020 PMCID: PMC8931318 DOI: 10.1073/pnas.2118871119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
SignificanceJuvenile hormone (JH), a sesquiterpenoid, regulates many aspects of insect development, including maintenance of the larval stage by preventing metamorphosis. In contrast, ecdysteroids promote metamorphosis by inducing the E93 transcription factor, which triggers apoptosis of larval cells and remodeling of the larval midgut. We discovered that JH suppresses precocious larval midgut-remodeling by inducing an epigenetic modifier, histone deacetylase 3 (HDAC3). JH-induced HDAC3 deacetylates the histone H4 localized at the promoters of proapoptotic genes, resulting in the suppression of these genes. This eventually prevents programmed cell death of midgut cells and midgut-remodeling during larval stages. These studies identified a previously unknown mechanism of JH action in blocking premature remodeling of the midgut during larval feeding stages.
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Homma Y, Inui T, Kayukawa T, Toga K, Shinoda T, Togawa T. The Mitochondrial Phosphatase PTPMT1 is Required for the Proper Growth Rate in the Red Flour Beetle, Tribolium castaneum. Zoolog Sci 2022; 39:236-241. [DOI: 10.2108/zs210092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/27/2021] [Indexed: 11/17/2022]
Affiliation(s)
- Yuri Homma
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Sakurajyosui 3-25-40, Setagaya-ku, Tokyo 156-8550, Japan
| | - Tomohiro Inui
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Ohwashi 1-2, Tsukuba 305-8634, Japan
| | - Takumi Kayukawa
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Ohwashi 1-2, Tsukuba 305-8634, Japan
| | - Kouhei Toga
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Sakurajyosui 3-25-40, Setagaya-ku, Tokyo 156-8550, Japan
| | - Tetsuro Shinoda
- Faculty of Food and Agricultural Sciences, Fukushima University, Kanayagawa 1, Fukushima 960-1296, Japan
| | - Toru Togawa
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Sakurajyosui 3-25-40, Setagaya-ku, Tokyo 156-8550, Japan
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Molecular mechanisms underlying metamorphosis in the most-ancestral winged insect. Proc Natl Acad Sci U S A 2022; 119:2114773119. [PMID: 35217609 PMCID: PMC8892354 DOI: 10.1073/pnas.2114773119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2022] [Indexed: 11/18/2022] Open
Abstract
As caterpillars metamorphose to butterflies, insects change their appearance dramatically through metamorphosis. Some insects have an immobile pupal stage for morphological remodeling (homometaboly). Other insects, such as cockroaches, have no pupal stage, and the juveniles and adults are morphologically similar (hemimetaboly). Notably, among the most-ancestral hemimetabolous insects, dragonflies drastically alter their appearance from aquatic nymphs to aerial adults. In dragonflies, we showed that transcription factors Kr-h1 and E93 are essential for regulating metamorphosis as in other insects, while broad, the master gene for pupation in holometabolous insects, regulates a number of both nymph-specific genes and adult-specific genes, providing insight into what evolutionary trajectory the key transcription factor broad has experienced before ending up with governing pupation and holometaboly. Insects comprise over half of the described species, and the acquisition of metamorphosis must have contributed to their diversity and prosperity. The order Odonata (dragonflies and damselflies) is among the most-ancestral insects with drastic morphological changes upon metamorphosis, in which understanding of the molecular mechanisms will provide insight into the evolution of incomplete and complete metamorphosis in insects. In order to identify metamorphosis-related genes in Odonata, we performed comprehensive RNA-sequencing of the blue-tailed damselfly Ischnura senegalensis at different developmental stages. Comparative RNA-sequencing analyses between nymphs and adults identified eight nymph-specific and seven adult-specific transcripts. RNA interference (RNAi) of these candidate genes demonstrated that three transcription factors, Krüppel homolog 1 (Kr-h1), broad, and E93 play important roles in metamorphosis of both I. senegalensis and a phylogenetically distant dragonfly, Pseudothemis zonata. E93 is essential for adult morphogenesis, and RNAi of Kr-h1 induced precocious metamorphosis in epidermis via up-regulation of E93. Precocious metamorphosis was also induced by RNAi of the juvenile hormone receptor Methoprene-tolerant (Met), confirming that the regulation of metamorphosis by the MEKRE93 (Met-Kr-h1-E93) pathway is conserved across diverse insects including the basal insect lineage Odonata. Notably, RNAi of broad produced unique grayish pigmentation on the nymphal abdominal epidermis. Survey of downstream genes for Kr-h1, broad, and E93 uncovered that unlike other insects, broad regulates a substantial number of nymph-specific and adult-specific genes independently of Kr-h1 and E93. These findings highlight the importance of functional changes and rewiring of the transcription factors Kr-h1, broad, and E93 in the evolution of insect metamorphosis.
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Lam G, Nam HJ, Velentzas PD, Baehrecke EH, Thummel CS. Drosophila E93 promotes adult development and suppresses larval responses to ecdysone during metamorphosis. Dev Biol 2022; 481:104-115. [PMID: 34648816 PMCID: PMC8665130 DOI: 10.1016/j.ydbio.2021.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 01/03/2023]
Abstract
Pulses of the steroid hormone ecdysone act through transcriptional cascades to direct the major developmental transitions during the Drosophila life cycle. These include the prepupal ecdysone pulse, which occurs 10 hours after pupariation and triggers the onset of adult morphogenesis and larval tissue destruction. E93 encodes a transcription factor that is specifically induced by the prepupal pulse of ecdysone, supporting a model proposed by earlier work that it specifies the onset of adult development. Although a number of studies have addressed these functions for E93, little is known about its roles in the salivary gland where the E93 locus was originally identified. Here we show that E93 is required for development through late pupal stages, with mutants displaying defects in adult differentiation and no detectable effect on the destruction of larval salivary glands. RNA-seq analysis demonstrates that E93 regulates genes involved in development and morphogenesis in the salivary glands, but has little effect on cell death gene expression. We also show that E93 is required to direct the proper timing of ecdysone-regulated gene expression in salivary glands, and that it suppresses earlier transcriptional programs that occur during larval and prepupal stages. These studies support the model that the stage-specific induction of E93 in late prepupae provides a critical signal that defines the end of larval development and the onset of adult differentiation.
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Affiliation(s)
- Geanette Lam
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 5100, Salt Lake City, UT 84112 USA
| | - Hyuck-Jin Nam
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 5100, Salt Lake City, UT 84112 USA
| | - Panagiotis D. Velentzas
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605 USA
| | - Eric H. Baehrecke
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605 USA
| | - Carl S. Thummel
- Department of Human Genetics, University of Utah School of Medicine, 15 N 2030 E Rm 5100, Salt Lake City, UT 84112 USA,Corresponding author. (C.S. Thummel)
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28
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Suzuki Y, Toh L. Constraints and Opportunities for the Evolution of Metamorphic Organisms in a Changing Climate. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.734031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We argue that developmental hormones facilitate the evolution of novel phenotypic innovations and timing of life history events by genetic accommodation. Within an individual’s life cycle, metamorphic hormones respond readily to environmental conditions and alter adult phenotypes. Across generations, the many effects of hormones can bias and at times constrain the evolution of traits during metamorphosis; yet, hormonal systems can overcome constraints through shifts in timing of, and acquisition of tissue specific responses to, endocrine regulation. Because of these actions of hormones, metamorphic hormones can shape the evolution of metamorphic organisms. We present a model called a developmental goblet, which provides a visual representation of how metamorphic organisms might evolve. In addition, because developmental hormones often respond to environmental changes, we discuss how endocrine regulation of postembryonic development may impact how organisms evolve in response to climate change. Thus, we propose that developmental hormones may provide a mechanistic link between climate change and organismal adaptation.
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Chafino S, Martín D, Franch-Marro X. Activation of EGFR signaling by Tc-Vein and Tc-Spitz regulates the metamorphic transition in the red flour beetle Tribolium castaneum. Sci Rep 2021; 11:18807. [PMID: 34552169 PMCID: PMC8458297 DOI: 10.1038/s41598-021-98334-9] [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: 05/12/2021] [Accepted: 08/25/2021] [Indexed: 02/08/2023] Open
Abstract
Animal development relies on a sequence of specific stages that allow the formation of adult structures with a determined size. In general, juvenile stages are dedicated mainly to growth, whereas last stages are devoted predominantly to the maturation of adult structures. In holometabolous insects, metamorphosis marks the end of the growth period as the animals stops feeding and initiate the final differentiation of the tissues. This transition is controlled by the steroid hormone ecdysone produced in the prothoracic gland. In Drosophila melanogaster different signals have been shown to regulate the production of ecdysone, such as PTTH/Torso, TGFß and Egfr signaling. However, to which extent the roles of these signals are conserved remains unknown. Here, we study the role of Egfr signaling in post-embryonic development of the basal holometabolous beetle Tribolium castaneum. We show that Tc-Egfr and Tc-pointed are required to induced a proper larval-pupal transition through the control of the expression of ecdysone biosynthetic genes. Furthermore, we identified an additional Tc-Egfr ligand in the Tribolium genome, the neuregulin-like protein Tc-Vein (Tc-Vn), which contributes to induce larval-pupal transition together with Tc-Spitz (Tc-Spi). Interestingly, we found that in addition to the redundant role in the control of pupa formation, each ligand possesses different functions in organ morphogenesis. Whereas Tc-Spi acts as the main ligand in urogomphi and gin traps, Tc-Vn is required in wings and elytra. Altogether, our findings show that in Tribolium, post-embryonic Tc-Egfr signaling activation depends on the presence of two ligands and that its role in metamorphic transition is conserved in holometabolous insects.
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Affiliation(s)
- Sílvia Chafino
- grid.507636.10000 0004 0424 5398Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Passeig de la Barceloneta 37, 08003 Barcelona, Catalonia Spain
| | - David Martín
- grid.507636.10000 0004 0424 5398Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Passeig de la Barceloneta 37, 08003 Barcelona, Catalonia Spain
| | - Xavier Franch-Marro
- grid.507636.10000 0004 0424 5398Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Passeig de la Barceloneta 37, 08003 Barcelona, Catalonia Spain
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30
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Fritzsche S, Hunnekuhl VS. Cell-specific expression and individual function of prohormone convertase PC1/3 in Tribolium larval growth highlights major evolutionary changes between beetle and fly neuroendocrine systems. EvoDevo 2021; 12:9. [PMID: 34187565 PMCID: PMC8244231 DOI: 10.1186/s13227-021-00179-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 06/14/2021] [Indexed: 11/15/2022] Open
Abstract
Background The insect neuroendocrine system acts in the regulation of physiology, development and growth. Molecular evolution of this system hence has the potential to allow for major biological differences between insect groups. Two prohormone convertases, PC1/3 and PC2, are found in animals and both function in the processing of neuropeptide precursors in the vertebrate neurosecretory pathway. Whereas PC2-function is conserved between the fly Drosophila and vertebrates, ancestral PC1/3 was lost in the fly lineage and has not been functionally studied in any protostome. Results In order to understand its original functions and the changes accompanying the gene loss in the fly, we investigated PC1/3 and PC2 expression and function in the beetle Tribolium castaneum. We found that PC2 is broadly expressed in the nervous system, whereas surprisingly, PC1/3 expression is restricted to specific cell groups in the posterior brain and suboesophageal ganglion. Both proteases have parallel but non-redundant functions in adult beetles’ viability and fertility. Female infertility following RNAi is caused by a failure to deposit sufficient yolk to the developing oocytes. Larval RNAi against PC2 produced moulting defects where the larvae were not able to shed their old cuticle. This ecdysis phenotype was also observed in a small subset of PC1/3 knockdown larvae and was strongest in a double knockdown. Unexpectedly, most PC1/3-RNAi larvae showed strongly reduced growth, but went through larval moults despite minimal to zero weight gain. Conclusions The cell type-specific expression of PC1/3 and its essential requirement for larval growth highlight the important role of this gene within the insect neuroendocrine system. Genomic conservation in most insect groups suggests that it has a comparable individual function in other insects as well, which has been replaced by alternative mechanisms in flies. Supplementary Information The online version contains supplementary material available at 10.1186/s13227-021-00179-w.
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Affiliation(s)
- Sonja Fritzsche
- Johann-Friedrich-Blumenbach Institute, GZMB, Göttingen University, Göttingen, Germany
| | - Vera S Hunnekuhl
- Johann-Friedrich-Blumenbach Institute, GZMB, Göttingen University, Göttingen, Germany.
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31
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Wang X, Ding Y, Lu X, Geng D, Li S, Raikhel AS, Zou Z. The ecdysone-induced protein 93 is a key factor regulating gonadotrophic cycles in the adult female mosquito Aedes aegypti. Proc Natl Acad Sci U S A 2021; 118:e2021910118. [PMID: 33593917 PMCID: PMC7923369 DOI: 10.1073/pnas.2021910118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Repeated blood feedings are required for adult female mosquitoes to maintain their gonadotrophic cycles, enabling them to be important pathogen carriers of human diseases. Elucidating the molecular mechanism underlying developmental switches between these mosquito gonadotrophic cycles will provide valuable insight into mosquito reproduction and could aid in the identification of targets to disrupt these cycles, thereby reducing disease transmission. We report here that the transcription factor ecdysone-induced protein 93 (E93), previously implicated in insect metamorphic transitions, plays a key role in determining the gonadotrophic cyclicity in adult females of the major arboviral vector Aedes aegypti Expression of the E93 gene in mosquitoes is down-regulated by juvenile hormone (JH) and up-regulated by 20-hydroxyecdysone (20E). We find that E93 controls Hormone Receptor 3 (HR3), the transcription factor linked to the termination of reproductive cycles. Moreover, knockdown of E93 expression via RNAi impaired fat body autophagy, suggesting that E93 governs autophagy-induced termination of vitellogenesis. E93 RNAi silencing prior to the first gonadotrophic cycle affected normal progression of the second cycle. Finally, transcriptomic analysis showed a considerable E93-dependent decline in the expression of genes involved in translation and metabolism at the end of a reproductive cycle. In conclusion, our data demonstrate that E93 acts as a crucial factor in regulating reproductive cycle switches in adult female mosquitoes.
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Affiliation(s)
- Xueli Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, People's Republic of China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, 100049 Beijing, People's Republic of China
| | - Yike Ding
- Department of Entomology, University of California, Riverside, CA 92521
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
| | - Xiangyang Lu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, People's Republic of China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, 100049 Beijing, People's Republic of China
| | - Danqian Geng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, People's Republic of China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, 100049 Beijing, People's Republic of China
| | - Shan Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, People's Republic of China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, 100049 Beijing, People's Republic of China
| | - Alexander S Raikhel
- Department of Entomology, University of California, Riverside, CA 92521;
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
| | - Zhen Zou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, People's Republic of China;
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, 100049 Beijing, People's Republic of China
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32
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Martín D, Chafino S, Franch-Marro X. How stage identity is established in insects: the role of the Metamorphic Gene Network. CURRENT OPINION IN INSECT SCIENCE 2021; 43:29-38. [PMID: 33075581 DOI: 10.1016/j.cois.2020.10.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/07/2020] [Accepted: 10/07/2020] [Indexed: 06/11/2023]
Abstract
Proper formation of adult insects requires the integration of spatial and temporal regulatory axes. Whereas spatial information confers identity to each tissue, organ and appendage, temporal information specifies at which stage of development the animal is. Regardless of the type of post-embryonic development, either hemimetabolous or holometabolous, temporal specificity is achieved through interactions between the temporal identity genes Kr-h1, E93 and Br-C, whose sequential expression is controlled by the two major developmental hormones, 20-hydroxyecdysone and Juvenile hormone. Given the intimate regulatory connection between these three factors to specify life stage identity, we dubbed the regulatory axis that comprises these genes as the Metamorphic Gene Network (MGN). In this review, we survey the molecular mechanisms underlying the control by the MGN of stage identity and progression in hemimetabolous and holometabolous insects.
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Affiliation(s)
- David Martín
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain.
| | - Silvia Chafino
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Xavier Franch-Marro
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain.
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33
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Niederhuber MJ, McKay DJ. Mechanisms underlying the control of dynamic regulatory element activity and chromatin accessibility during metamorphosis. CURRENT OPINION IN INSECT SCIENCE 2021; 43:21-28. [PMID: 32979530 PMCID: PMC7985040 DOI: 10.1016/j.cois.2020.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 08/25/2020] [Indexed: 05/10/2023]
Abstract
Cis-regulatory modules of metazoan genomes determine the when and where of gene expression during development. Here we discuss insights into the genetic and molecular mechanisms behind cis-regulatory module usage that have come from recent application of genomics assays to insect metamorphosis. Assays including FAIRE-seq, ATAC-seq, and CUT&RUN indicate that sequential changes in chromatin accessibility play a key role in mediating stage-specific cis-regulatory module activity and gene expression. We review the current understanding of what controls precisely coordinated changes in chromatin accessibility during metamorphosis and describe evidence that points to systemic hormone signaling as a primary signal to trigger genome-wide shifts in accessibility patterns and cis-regulatory module usage.
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Affiliation(s)
- Matthew J Niederhuber
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States; Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States; Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States; Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States
| | - Daniel J McKay
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States; Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States; Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, United States.
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34
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Vea IM, Minakuchi C. Atypical insects: molecular mechanisms of unusual life history strategies. CURRENT OPINION IN INSECT SCIENCE 2021; 43:46-53. [PMID: 33065338 DOI: 10.1016/j.cois.2020.09.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/23/2020] [Accepted: 09/29/2020] [Indexed: 06/11/2023]
Abstract
Metamorphosis undeniably shaped the evolutionary success of winged insects. So far, what we know about the hormonal regulation and molecular mechanisms controlling insect metamorphosis lies on the understanding of complete and incomplete metamorphosis. Rarer types of metamorphosis are overlooked, yet they could provide important insights as they represent deviations in life history strategies that are associated with unique ecological traits. The molecular mechanisms of these atypical metamorphoses are still poorly understood. With the rise of next-generation sequencing, and increasing interest in emerging organismal systems, it is now possible to start exploring the molecular mechanisms underlying atypical metamorphoses in insects. By focusing on neometaboly and paedomorphosis, we discuss how exploring their molecular mechanisms can complete our understanding on the evolution of insects and impact applied research areas. Continued decrease in next-generation sequencing costs and progress in genome editing will help decipher the proximate mechanisms of unusual life history strategies in insects.
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Affiliation(s)
- Isabelle M Vea
- University of Illinois at Chicago, Department of Biological Sciences, Chicago, IL, USA
| | - Chieka Minakuchi
- Nagoya University, Graduate School of Bio-agricultural Sciences, Nagoya, Japan
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35
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He LL, Shin SH, Wang Z, Yuan I, Weschler R, Chiou A, Koyama T, Nijhout HF, Suzuki Y. Mechanism of threshold size assessment: Metamorphosis is triggered by the TGF-beta/Activin ligand Myoglianin. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 126:103452. [PMID: 32822817 DOI: 10.1016/j.ibmb.2020.103452] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/02/2020] [Accepted: 08/02/2020] [Indexed: 06/11/2023]
Abstract
Although the mechanisms that control growth are now well understood, the mechanism by which animals assess their body size remains one of the great puzzles in biology. The final larval instar of holometabolous insects, after which growth stops and metamorphosis begins, is specified by a threshold size. We investigated the mechanism of threshold size assessment in the tobacco hornworm, Manduca sexta. The threshold size was found to change depending on the amount of exposure to poor nutrient conditions whereas hypoxia treatment consistently led to a lower threshold size. Under these various conditions, the mass of the muscles plus integuments was correlated with the threshold size. Furthermore, the expression of myoglianin (myo) increased at the threshold size in both M. sexta and Tribolium castaneum. Knockdown of myo in T. castaneum led to larvae that underwent supernumerary larval molts and stayed in the larval stage permanently even after passing the threshold size. We propose that increasing levels of Myo produced by the growing tissues allow larvae to assess their body size and trigger metamorphosis at the threshold size.
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Affiliation(s)
- Lorrie L He
- Department of Biological Sciences, 106 Central St., Wellesley College, Wellesley, MA, 02481, USA
| | - Sara H Shin
- Department of Biological Sciences, 106 Central St., Wellesley College, Wellesley, MA, 02481, USA
| | - Zhou Wang
- Department of Biological Sciences, 106 Central St., Wellesley College, Wellesley, MA, 02481, USA
| | - Isabelle Yuan
- Department of Biological Sciences, 106 Central St., Wellesley College, Wellesley, MA, 02481, USA
| | - Ruthie Weschler
- Department of Biological Sciences, 106 Central St., Wellesley College, Wellesley, MA, 02481, USA
| | - Allison Chiou
- Department of Biological Sciences, 106 Central St., Wellesley College, Wellesley, MA, 02481, USA
| | - Takashi Koyama
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156, Oeiras, Portugal; Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | | | - Yuichiro Suzuki
- Department of Biological Sciences, 106 Central St., Wellesley College, Wellesley, MA, 02481, USA.
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Gijbels M, Marchal E, Verdonckt TW, Bruyninckx E, Vanden Broeck J. RNAi-Mediated Knockdown of Transcription Factor E93 in Nymphs of the Desert Locust ( Schistocerca gregaria) Inhibits Adult Morphogenesis and Results in Supernumerary Juvenile Stages. Int J Mol Sci 2020; 21:E7518. [PMID: 33053862 PMCID: PMC7590052 DOI: 10.3390/ijms21207518] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 02/02/2023] Open
Abstract
Postembryonic development of insects is coordinated by juvenile hormone (JH) together with ecdysteroids. Whereas the JH early response gene krüppel-homolog 1 (Kr-h1) plays a crucial role in the maintenance of juvenile characteristics during consecutive larval stages, the ecdysteroid-inducible early gene E93 appears to be a key factor promoting metamorphosis and adult morphogenesis. Here, we report on the developmental and molecular consequences of an RNAi-mediated knockdown of SgE93 in the desert locust, Schistocerca gregaria, a hemimetabolan species. Our experimental data show that injection of gregarious locust nymphs with a double-stranded RNA construct targeting the SgE93 transcript inhibited the process of metamorphosis and instead led to supernumerary nymphal stages. These supernumerary nymphal instars still displayed juvenile morphological features, such as a nymphal color scheme and body shape, while they reached the physical body size of the adult locusts, or even surpassed it after the next supernumerary molt. Interestingly, when compared to control locusts, the total duration of the fifth and normally final nymphal (N5) stage was shorter than normal. This appeared to correspond with temporal and quantitative changes in hemolymph ecdysteroid levels, as well as with altered expression of the rate-limiting Halloween gene, Spook (SgSpo). In addition, the levels of the ecdysone receptor (SgEcR) and retinoïd X receptor (SgRXR) transcripts were altered, indicating that silencing SgE93 affects both ecdysteroid synthesis and signaling. Upon knockdown of SgE93, a very potent upregulation of the SgKr-h1 transcript levels was observed in both head and fat body, while no significant changes were detected in the transcript levels of SgJHAMT and SgCYP15A1, the enzymes that catalyze the two final steps in JH biosynthesis. Moreover, the process of molting was disturbed in these supernumerary nymphs. While attempting ecdysis to the next stage, 50% of the N6 and all N7 nymphal instars eventually died. S. gregaria is a very harmful, swarm-forming pest species that destroys crops and threatens food security in many of the world's poorest countries. We believe that a better knowledge of the mechanisms of postembryonic development may contribute to the discovery of novel, more selective and sustainable strategies for controlling gregarious locust populations. In this context, identification of molecular target candidates that are capable of significantly reducing the fitness of this devastating swarming pest will be of crucial importance.
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Affiliation(s)
- Marijke Gijbels
- Research group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (E.M.); (T.W.V.); (E.B.)
| | - Elisabeth Marchal
- Research group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (E.M.); (T.W.V.); (E.B.)
- Life Science Technologies, Imec, Kapeldreef 75, B-3001 Leuven, Belgium
| | - Thomas Wolf Verdonckt
- Research group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (E.M.); (T.W.V.); (E.B.)
| | - Evert Bruyninckx
- Research group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (E.M.); (T.W.V.); (E.B.)
| | - Jozef Vanden Broeck
- Research group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (E.M.); (T.W.V.); (E.B.)
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Abstract
The evolution of insect metamorphosis is one of the most important sagas in animal history, transforming small, obscure soil arthropods into a dominant terrestrial group that has profoundly shaped the evolution of terrestrial life. The evolution of flight initiated the trajectory towards metamorphosis, favoring enhanced differences between juvenile and adult stages. The initial step modified postembryonic development, resulting in the nymph-adult differences characteristic of hemimetabolous species. The second step was to complete metamorphosis, holometaboly, and occurred by profoundly altering embryogenesis to produce a larval stage, the nymph becoming the pupa to accommodate the deferred development needed to make the adult. These changing life history patterns were intimately linked to two hormonal systems, the ecdysteroids and the juvenile hormones (JH), which function in both embryonic and postembryonic domains and control the stage-specifying genes Krüppel homolog 1 (Kr-h1), broad and E93. The ecdysteroids induce and direct molting through the ecdysone receptor (EcR), a nuclear hormone receptor with numerous targets including a conserved transcription factor network, the 'Ashburner cascade', which translates features of the ecdysteroid peak into the different phases of the molt. With the evolution of metamorphosis, ecdysteroids acquired a metamorphic function that exploited the repressor capacity of the unliganded EcR, making it a hormone-controlled gateway for the tissue development preceding metamorphosis. JH directs ecdysteroid action, controlling Kr-h1 expression which in turn regulates the other stage-specifying genes. JH appears in basal insect groups as their embryos shift from growth and patterning to differentiation. As a major portion of embryogenesis was deferred to postembryonic life with the evolution of holometaboly, JH also acquired a potent role in regulating postembryonic growth and development. Details of its involvement in broad expression and E93 suppression have been modified as life cycles became more complex and likely underlie some of the changes seen in the shift from incomplete to complete metamorphosis.
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Affiliation(s)
- James W Truman
- Department of Biology and Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA.
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Cui K, He L, Zhang Z, Zhang L, Mu W, Liu F. Effects of benzothiazole on survival for reduced reproduction and development in Tribolium castaneum Herbst (Coleoptera: Tenebrionidae). PEST MANAGEMENT SCIENCE 2020; 76:3088-3095. [PMID: 32279408 DOI: 10.1002/ps.5860] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/28/2020] [Accepted: 04/12/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), is an important stored-product pest that is distributed worldwide and has developed resistance to many insecticides. Identifying novel and effective alternative insecticides is important for the control of T. castaneum. The volatile compound benzothiazole has been identified as having great acute toxic activity against T. castaneum. However, a comprehensive evaluation of a new insecticide should include both direct toxic effects and sublethal effects. The aim of this study was therefore to evaluate the effects of benzothiazole on the development and reproduction of T. castaneum. RESULTS Exposure of fourth-instar larvae to lethal and sublethal concentrations of benzothiazole (LC10 , LC30 and LC50 ) significantly decreased pupation rates, food intake and growth rates in T. castaneum. Larval duration was significantly reduced by approximately 1 day in the LC30 and LC50 treatment groups. The LC50 benzothiazole caused a significant decrease in the weight of pupae and adults, fecundity and egg hatchability. Increased and decreased nutrient (carbohydrate and lipid) contents were observed in surviving larvae and pupae, respectively. The LC30 and LC50 treatments caused the down-regulation of five growth-positive regulated genes (PI3K, AKT, CyclinE, S6K1 and S6K2) and the up-regulation of two growth-negative regulated genes (4EBP and FOXO). CONCLUSION Benzothiazole presented adverse effects on the development and reproduction of T. castaneum, further supporting benzothiazole as a highly active compound in stored-product protection. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Kaidi Cui
- Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Shandong Agricultural University, Tai'an, People's Republic of China
- College of Plant Protection, Shandong Agricultural University, Tai'an, People's Republic of China
| | - Leiming He
- Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Shandong Agricultural University, Tai'an, People's Republic of China
- College of Plant Protection, Shandong Agricultural University, Tai'an, People's Republic of China
| | - Zhengqun Zhang
- College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
| | - Lingyan Zhang
- Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Shandong Agricultural University, Tai'an, People's Republic of China
- College of Plant Protection, Shandong Agricultural University, Tai'an, People's Republic of China
| | - Wei Mu
- Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Shandong Agricultural University, Tai'an, People's Republic of China
- College of Plant Protection, Shandong Agricultural University, Tai'an, People's Republic of China
| | - Feng Liu
- Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Shandong Agricultural University, Tai'an, People's Republic of China
- College of Plant Protection, Shandong Agricultural University, Tai'an, People's Republic of China
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Gijbels M, Schellens S, Schellekens T, Bruyninckx E, Marchal E, Vanden Broeck J. Precocious Downregulation of Krüppel-Homolog 1 in the Migratory Locust, Locusta migratoria, Gives Rise to An Adultoid Phenotype with Accelerated Ovarian Development but Disturbed Mating and Oviposition. Int J Mol Sci 2020; 21:E6058. [PMID: 32842716 PMCID: PMC7503607 DOI: 10.3390/ijms21176058] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 01/29/2023] Open
Abstract
Krüppel-homolog 1 (Kr-h1) is a zinc finger transcription factor maintaining the status quo in immature insect stages and promoting reproduction in adult insects through the transduction of the Juvenile Hormone (JH) signal. Knockdown studies have shown that precocious silencing of Kr-h1 in the immature stages results in the premature development of adult features. However, the molecular characteristics and reproductive potential of these premature adult insect stages are still poorly understood. Here we report on an adult-like or 'adultoid' phenotype of the migratory locust, Locusta migratoria, obtained after a premature metamorphosis induced by the silencing of LmKr-h1 in the penultimate instar. The freshly molted adultoid shows precocious development of adult features, corresponding with increased transcript levels of the adult specifier gene LmE93. Furthermore, accelerated ovarian maturation and vitellogenesis were observed in female adultoids, coinciding with elevated expression of LmCYP15A1 in corpora allata (CA) and LmKr-h1 and vitellogenin genes (LmVg) in fat body, whereas LmE93 and Methoprene-tolerant (LmMet) transcript levels decreased in fat body. In adultoid ovaries, expression of the Halloween genes, Spook (LmSpo) and Phantom (LmPhm), was elevated as well. In addition, the processes of mating and oviposition were severely disturbed in these females. L. migratoria is a well-known, swarm-forming pest insect that can destroy crops and harvests in some of the world's poorest countries. As such, a better understanding of factors that are capable of significantly reducing the reproductive potential of this pest may be of crucial importance for the development of novel locust control strategies.
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Affiliation(s)
- Marijke Gijbels
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (S.S.); (T.S.); (E.B.)
| | - Sam Schellens
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (S.S.); (T.S.); (E.B.)
| | - Tine Schellekens
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (S.S.); (T.S.); (E.B.)
| | - Evert Bruyninckx
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (S.S.); (T.S.); (E.B.)
| | - Elisabeth Marchal
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (S.S.); (T.S.); (E.B.)
- Life Science Technologies, Imec, Kapeldreef 75, B- 3001 Leuven, Belgium
| | - Jozef Vanden Broeck
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Zoological Institute, Naamsestraat 59 box 2465, 3000 Leuven, Belgium; (M.G.); (S.S.); (T.S.); (E.B.)
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40
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Eid DM, Chereddy SCRR, Palli SR. The effect of E93 knockdown on female reproduction in the red flour beetle, Tribolium castaneum. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 104:e21688. [PMID: 32394503 PMCID: PMC9939234 DOI: 10.1002/arch.21688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/28/2020] [Accepted: 04/20/2020] [Indexed: 05/07/2023]
Abstract
The E93 transcription factor is a member of helix-turn-helix transcription factor family containing a Pip-squeak motif. This ecdysone primary response gene was identified as a regulator of cell death in Drosophila melanogaster where it is involved in ecdysone-induced autophagy and caspase activity that mediate degeneration of larval tissues during metamorphosis from larva to pupa. However, its function in adult insects is not well studied. To study E93 function in the red flour beetle, Tribolium castaneum, double-stranded RNA (dsRNA) targeting E93 (dsE93) was injected into newly emerged adults. Knockdown of E93 caused a decrease in the synthesis of vitellogenin (Vg), oocyte development, and egg-laying. Sequencing of RNA isolated from adults injected with dsE93 and control dsmalE (dsRNA targeting Escherichia coli malE gene) followed by differential gene expression analysis showed upregulation of genes involved in the metabolism of reserved nutrients. E93 knockdown induced changes in gene expression resulted in a decrease in Vg synthesis in the fat body and oocyte maturation in ovaries. Mating experiments showed that females injected with dsE93 did not lay eggs. Knockdown of E93 caused a reduction in the number and size of lipid droplets in the fat body when compared with that in control beetles injected with dsmalE. These data suggest that during the first 2-3 days after the emergence of adult females, E93 suppresses genes coding for enzymes that metabolize reserved nutrients until initiation of vitellogenesis and oogenesis.
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Affiliation(s)
- Duaa Musleh Eid
- Department of Entomology, University of Kentucky, Lexington, Kentucky
| | | | - Subba Reddy Palli
- Department of Entomology, University of Kentucky, Lexington, Kentucky
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Zhu GH, Chereddy SCRR, Howell JL, Palli SR. Genome editing in the fall armyworm, Spodoptera frugiperda: Multiple sgRNA/Cas9 method for identification of knockouts in one generation. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 122:103373. [PMID: 32276113 DOI: 10.1016/j.ibmb.2020.103373] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/26/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
The CRISPR/Cas9 system is an efficient genome editing method that can be used in functional genomics research. The fall armyworm, Spodoptera frugiperda, is a serious agricultural pest that has spread over most of the world. However, very little information is available on functional genomics for this insect. We performed CRISPR/Cas9-mediated site-specific mutagenesis of three target genes: two marker genes [Biogenesis of lysosome-related organelles complex 1 subunit 2 (BLOS2) and tryptophan 2, 3-dioxygenase (TO)], and a developmental gene, E93 (a key ecdysone-induced transcription factor that promotes adult development). The knockouts (KO) of BLOS2, TO and E93 induced translucent mosaic integument, olive eye color, and larval-pupal intermediate phenotypes, respectively. Sequencing RNA isolated from wild-type and E93 KO insects showed that E93 promotes adult development by influencing the expression of the genes coding for transcription factor, Krüppel homolog 1, the pupal specifier, Broad-Complex, serine proteases, and heat shock proteins. Often, gene-edited insects display mosaicism in which only a fraction of the cells are edited as intended, and establishing a homozygous line is both costly and time-consuming. To overcome these limitations, a method to completely KO the target gene in S. frugiperda by injecting the Cas9 protein and multiple sgRNAs targeting one exon of the E93 gene into embryos was developed. Ten percent of the G0 larvae exhibited larval-pupal intermediates. The mutations were confirmed by T7E1 assay, and the mutation frequency was determined as >80%. Complete KO of the E93 gene was achieved in one generation using the multiple sgRNA method, demonstrating a powerful approach to improve genome editing in lepidopteran and other non-model insects.
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Affiliation(s)
- Guan-Heng Zhu
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
| | - Shankar C R R Chereddy
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
| | - Jeffrey L Howell
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA
| | - Subba Reddy Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA.
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Kumagai H, Kunieda T, Nakamura K, Matsumura Y, Namiki M, Kohno H, Kubo T. Developmental stage-specific distribution and phosphorylation of Mblk-1, a transcription factor involved in ecdysteroid-signaling in the honey bee brain. Sci Rep 2020; 10:8735. [PMID: 32457433 PMCID: PMC7250831 DOI: 10.1038/s41598-020-65327-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 04/28/2020] [Indexed: 01/18/2023] Open
Abstract
In the honey bee, the mushroom bodies (MBs), a higher-order center in insect brain, comprise interneurons termed Kenyon cells (KCs). We previously reported that Mblk-1, which encodes a transcription factor involved in ecdysteroid-signaling, is expressed preferentially in the large-type KCs (lKCs) in the pupal and adult worker brain and that phosphorylation by the Ras/MAPK pathway enhances the transcriptional activity of Mblk-1 in vitro. In the present study, we performed immunoblotting and immunofluorescence studies using affinity-purified anti-Mblk-1 and anti-phosphorylated Mblk-1 antibodies to analyze the distribution and phosphorylation of Mblk-1 in the brains of pupal and adult workers. Mblk-1 was preferentially expressed in the lKCs in both pupal and adult worker brains. In contrast, some Mblk-1 was phosphorylated almost exclusively in the pupal stages, and phosphorylated Mblk-1 was preferentially expressed in the MB neuroblasts and lKCs in pupal brains. Immunofluorescence studies revealed that both Mblk-1 and phosphorylated Mblk-1 are located in both the cytoplasm and nuclei of the lKC somata in the pupal and adult worker brains. These findings suggest that Mblk-1 plays a role in the lKCs in both pupal and adult stages and that phosphorylated Mblk-1 has pupal stage-specific functions in the MB neuroblasts and lKCs in the honey bee brain.
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Affiliation(s)
- Hitomi Kumagai
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Takekazu Kunieda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Korefumi Nakamura
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yasuhiro Matsumura
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Manami Namiki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Hiroki Kohno
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Takeo Kubo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan.
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Gaddelapati SC, Dhandapani RK, Palli SR. CREB-binding protein regulates metamorphosis and compound eye development in the yellow fever mosquito, Aedes aegypti. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194576. [PMID: 32389826 DOI: 10.1016/j.bbagrm.2020.194576] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 05/03/2020] [Accepted: 05/04/2020] [Indexed: 01/08/2023]
Abstract
Juvenile hormones (JH) and ecdysone coordinately regulate metamorphosis in Aedes aegypti. We studied the function of an epigenetic regulator and multifunctional transactivator, CREB binding protein (CBP) in A. aegypti. RNAi-mediated knockdown of CBP in Ae. aegypti larvae resulted in suppression of JH primary response gene, Krüppel-homolog 1 (Kr-h1), and induction of primary ecdysone response gene, E93, resulting in multiple effects including early metamorphosis, larval-pupal intermediate formation, mortality and inhibition of compound eye development. RNA sequencing identified hundreds of genes, including JH and ecdysone response genes regulated by CBP. In the presence of JH, CBP upregulates Kr-h1 by acetylating core histones at the Kr-h1 promoter and facilitating the recruitment of JH receptor and other proteins. CBP suppresses metamorphosis regulators, EcR-A, USP-A, BR-C, and E93 through the upregulation of Kr-h1 and E75A. CBP regulates the expression of core eye specification genes including those involved in TGF-β and EGFR signaling. These studies demonstrate that CBP is an essential player in JH and 20E action and regulates metamorphosis and compound eye development in Ae. aegypti.
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Affiliation(s)
| | | | - Subba Reddy Palli
- Department of Entomology, University of Kentucky, Lexington, KY 40546, USA.
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Belles X. Krüppel homolog 1 and E93: The doorkeeper and the key to insect metamorphosis. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 103:e21609. [PMID: 31385626 DOI: 10.1002/arch.21609] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/18/2019] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
Insect metamorphosis is regulated by two main hormones: ecdysone (20E), which promotes molting, and juvenile hormone (JH), which inhibits adult morphogenesis. The transduction mechanisms for the respective hormonal signals include the transcription factors Krüppel homolog 1 (Kr-h1) and E93, which are JH- and 20E-dependent, respectively. Kr-h1 is the main effector of the antimetamorphic action of JH, while E93 is a key promoter of metamorphosis. The ancestral regulatory axis of metamorphosis, which operates in insects with hemimetabolan (gradual) metamorphosis and is known as the MEKRE93 pathway, is based on Kr-h1 repression of E93. In the last juvenile stage, when the production of JH dramatically decreases, Kr-h1 expression is almost completely interrupted, E93 becomes upregulated and metamorphosis proceeds. The holometabolan (complete) metamorphosis mode of development includes the peculiar pupal stage, a sort of intermediate between the final larval instar and the adult stage. In holometabolan species, Broad-Complex (BR-C) transcription factors determine the pupal stage and E93 stimulates the expression of BR-C in the prepupa. The MEKRE93 pathway is conserved in holometabolan insects, which have added the E93/BR-C interaction loop to the ancestral (hemimetabolan) pathway during the evolution from hemimetaboly to holometaboly.
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Affiliation(s)
- Xavier Belles
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
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45
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Rolff J, Johnston PR, Reynolds S. Complete metamorphosis of insects. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190063. [PMID: 31438816 DOI: 10.1098/rstb.2019.0063] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The majority of described hexapod species are holometabolous insects, undergoing an extreme form of metamorphosis with an intercalated pupal stage between the larva and adult, in which organs and tissues are extensively remodelled and in some cases completely rebuilt. Here, we review how and why this developmental strategy has evolved. While there are many theories explaining the evolution of metamorphosis, many of which fit under the hypothesis of decoupling of life stages, there are few clear adaptive hypotheses on why complete metamorphosis evolved. We propose that the main adaptive benefit of complete metamorphosis is decoupling between growth and differentiation. This facilitates the exploitation of ephemeral resources and enhances the probability of the metamorphic transition escaping developmental size thresholds. The evolution of complete metamorphosis comes at the cost of exposure to predators, parasites and pathogens during pupal life and requires specific adaptations of the immune system at this time. Moreover, metamorphosis poses a challenge for the maintenance of symbionts and the gut microbiota, although it may also offer the benefit of allowing an extensive change in microbiota between the larval and adult stages. The regulation of metamorphosis by two main players, ecdysone and juvenile hormone, and the related signalling cascades are now relatively well understood. The mechanics of metamorphosis have recently been studied in detail because of the advent of micro-CT and research into the role of cell death in remodelling tissues and organs. We support the argument that the adult stage must necessarily have preceded the larval form of the insect. We do not resolve the still contentious question of whether the larva of insects in general originated through the modification of existing preadult forms or through heterochrony as a modified embryonic stage (pronymph), nor whether the holometabolous pupa arose as a modified hemimetabolous final stage larva. This article is part of the theme issue 'The evolution of complete metamorphosis'.
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Affiliation(s)
- Jens Rolff
- Evolutionary Biology, Institut für Biologie, Freie Universität Berlin, Berlin, Germany.,Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
| | - Paul R Johnston
- Evolutionary Biology, Institut für Biologie, Freie Universität Berlin, Berlin, Germany.,Berlin Center for Genomics in Biodiversity Research, Berlin, Germany.,Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Stuart Reynolds
- Department of Biology and Biochemistry, University of Bath, Bath, UK
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Jindra M. Where did the pupa come from? The timing of juvenile hormone signalling supports homology between stages of hemimetabolous and holometabolous insects. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190064. [PMID: 31438814 DOI: 10.1098/rstb.2019.0064] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Insect metamorphosis boasts spectacular cases of postembryonic development when juveniles undergo massive morphogenesis before attaining the adult form and function; in moths or flies the larvae do not even remotely resemble their adult parents. A selective advantage of complete metamorphosis (holometaboly) is that within one species the two forms with different lifestyles can exploit diverse habitats. It was the environmental adaptation and specialization of larvae, primarily the delay and internalization of wing development, that eventually required an intermediate stage that we call a pupa. It is a long-held and parsimonious hypothesis that the holometabolous pupa evolved through modification of a final juvenile stage of an ancestor developing through incomplete metamorphosis (hemimetaboly). Alternative hypotheses see the pupa as an equivalent of all hemimetabolous moulting cycles (instars) collapsed into one, and consider any preceding holometabolous larval instars free-living embryos stalled in development. Discoveries on juvenile hormone signalling that controls metamorphosis grant new support to the former hypothesis deriving the pupa from a final pre-adult stage. The timing of expression of genes that repress and promote adult development downstream of hormonal signals supports homology between postembryonic stages of hemimetabolous and holometabolous insects. This article is part of the theme issue 'The evolution of complete metamorphosis'.
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Affiliation(s)
- Marek Jindra
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice 370 05, Czech Republic
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Truman JW, Riddiford LM. The evolution of insect metamorphosis: a developmental and endocrine view. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190070. [PMID: 31438820 PMCID: PMC6711285 DOI: 10.1098/rstb.2019.0070] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Developmental, genetic and endocrine data from diverse taxa provide insight into the evolution of insect metamorphosis. We equate the larva–pupa–adult of the Holometabola to the pronymph–nymph–adult of hemimetabolous insects. The hemimetabolous pronymph is a cryptic embryonic stage with unique endocrinology and behavioural modifications that probably served as preadaptations for the larva. It develops in the absence of juvenile hormone (JH) as embryonic primordia undergo patterning and morphogenesis, the processes that were arrested for the evolution of the larva. Embryonic JH then drives tissue differentiation and nymph formation. Experimental treatment of pronymphs with JH terminates patterning and induces differentiation, mimicking the processes that occurred during the evolution of the larva. Unpatterned portions of primordia persist in the larva, becoming imaginal discs that form pupal and adult structures. Key transcription factors are associated with the holometabolous life stages: Krüppel-homolog 1 (Kr-h1) in the larva, broad in the pupa and E93 in the adult. Kr-h1 mediates JH action and is found whenever JH acts, while the other two genes direct the formation of their corresponding stages. In hemimetabolous forms, the pronymph has low Broad expression, followed by Broad expression through the nymphal moults, then a switch to E93 to form the adult. This article is part of the theme issue ‘The evolution of complete metamorphosis’.
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Affiliation(s)
- James W Truman
- Department of Biology, Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
| | - Lynn M Riddiford
- Department of Biology, Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
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