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Dong Y, Huang L, Liu L. Comparative analysis of testicular fusion in Spodoptera litura (cutworm) and Bombyx mori (silkworm): Histological and transcriptomic insights. Gen Comp Endocrinol 2024; 356:114562. [PMID: 38848820 DOI: 10.1016/j.ygcen.2024.114562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/09/2024]
Abstract
Spodoptera litura commonly known as the cutworm, is among the most destructive lepidopteran pests affecting over 120 plants species. The powerful destructive nature of this lepidopteran is attributable to its high reproductive capacity. The testicular fusion that occurs during metamorphosis from larvae to pupa in S.litura positively influences the reproductive success of the offspring. In contrast, Bombyx mori, the silkworm, retains separate testes throughout its life and does not undergo this fusion process. Microscopic examination reveals that during testicular fusion in S.litura, the peritoneal sheath becomes thinner and more translucent, whereas in B.mori, the analogous region thickens. The outer basement membrane in S.litura exhibits fractures, discontinuity, and uneven thickness accompanied by a significant presence of cellular secretions, large cell size, increased vesicles, liquid droplets, and a proliferation of rough endoplasmic reticulum and mitochondria. In contrast, the testicular peritoneal sheath of B.mori at comparable developmental stage exhibits minimal change. Comparative transcriptomic analysis of the testicular peritoneal sheath reveals a substantial difference in gene expression between the two species. The disparity in differential expressed genes (DEGs) is linked to an enrichment of numerous transcription factors, intracellular signaling pathways involving Ca2+ and GTPase, as well as intracellular protein transport and signaling pathways. Meanwhile, structural proteins including actin, chitin-binding proteins, membrane protein fractions, cell adhesion, extracellular matrix proteins are predominantly identified. Moreover, the study highlights the enrichment of endopeptidases, serine proteases, proteolytic enzymes and matrix metalloproteins, which may play a role in the degradation of the outer membrane. Five transcription factors-Slforkhead, Slproline, Slcyclic, Slsilk, and SlD-ETS were identified, and their expression pattern were confirmed by qRT-PCR. they are candidates for participating in the regulation of testicular fusion. Our findings underscore significant morphological and trancriptomic variation in the testicular peritoneal sheath of S.litura compared to the silkworm, with substantial changes at the transcriptomic level coinciding with testicular fusion. The research provides valuable clues for understanding the complex mechanisms underlying this unique phenomenon in insects.
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Affiliation(s)
- Yaqun Dong
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Lihua Huang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Lin Liu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
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Zhang J, Liu M, Wen L, Hua Y, Zhang R, Li S, Zafar J, Pang R, Xu H, Xu X, Jin F. MiR-2b-3p Downregulated PxTrypsin-9 Expression in the Larval Midgut to Decrease Cry1Ac Susceptibility of the Diamondback Moth, Plutella xylostella (L.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:2263-2276. [PMID: 38235648 DOI: 10.1021/acs.jafc.3c07678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Crystal (Cry) toxins, produced by Bacillus thuringiensis, are widely used as effective biological pesticides in agricultural production. However, insects always quickly evolve adaptations against Cry toxins within a few generations. In this study, we focused on the Cry1Ac protoxin activated by protease. Our results identified PxTrypsin-9 as a trypsin gene that plays a key role in Cry1Ac virulence in Plutella xylostella larvae. In addition, P. xylostella miR-2b-3p, a member of the micoRNA-2 (miR-2) family, was significantly upregulated by Cry1Ac protoxin and targeted to PxTrypsin-9 downregulated its expression. The mRNA level of PxTrypsin-9, regulated by miR-2b-3p, revealed an increased tolerance of P. xylostella larvae to Cry1Ac at the post-transcriptional level. Considering that miR-2b and trypsin genes are widely distributed in various pest species, our study provides the basis for further investigation of the roles of miRNAs in the regulation of the resistance to Cry1Ac and other insecticides.
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Affiliation(s)
- Jie Zhang
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Mingyou Liu
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Liang Wen
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Yanyan Hua
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Ruonan Zhang
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - ShuZhong Li
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Junaid Zafar
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Rui Pang
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Hanhong Xu
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Xiaoxia Xu
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Fengliang Jin
- National Key Laboratory of Green Pesticide, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
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Chikmagalur Nagaraja B, Karuppannasamy A, Ramasamy A, Cholenahalli Narayanappa A, Chalapathi P, Maligeppagol M. CRISPR/Cas9-mediated mutagenesis of Sex lethal (Sxl) gene impacts fertility of the Fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2023; 114:1-15. [PMID: 37452759 DOI: 10.1002/arch.22035] [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: 06/11/2023] [Revised: 06/27/2023] [Accepted: 07/05/2023] [Indexed: 07/18/2023]
Abstract
Identification of novel approaches for managing the global pest, the Fall armyworm, Spodoptera frugiperda, is the need of the hour, as it defies many management strategies including synthetic chemicals, Bt transgenics, and so on. Recently CRISPR/Cas9-based genome editing opened up newer avenues to design novel pest management strategies such as precision-guided sterile insect technique (pgSIT). In this regard, genes governing sex determination, egg reproduction, and spermatogenesis could be the prime targets for genome editing. This requires validation of the target genes, preferably by a nontransgenic DNA-free editing, before the final application. One such important gene regulating sex determination in Drosophila is the Sex lethal (Sxl). However, the function of Sxl is not highly conserved in other insects and, in particular, we are beginning to comprehend its role in Lepidoptera with only one reference available in Spodoptera litura till date. In the present study, we have edited the sxl gene of S. frugiperda through the delivery of ribonucleoprotein complex (sgRNA + Cas9) at G0 stage embryo, targeting the conserved region of all the documented five splice variants. Results clearly showed that editing of sxl gene impacted the overall fecundity and hatching rate. Therefore, Sxl could be one of the target genes for developing pgSIT approach for the management of S. frugiperda.
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Affiliation(s)
- Bhargava Chikmagalur Nagaraja
- Division of Basic Sciences, ICAR - Indian Institute of Horticultural Research, Bengaluru, Karnataka, India
- Department of Agricultural Entomology, University of Agricultural Sciences, Bengaluru, Karnataka, India
| | - Ashok Karuppannasamy
- Division of Basic Sciences, ICAR - Indian Institute of Horticultural Research, Bengaluru, Karnataka, India
- Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India
| | - Asokan Ramasamy
- Division of Basic Sciences, ICAR - Indian Institute of Horticultural Research, Bengaluru, Karnataka, India
| | - Anu Cholenahalli Narayanappa
- Division of Basic Sciences, ICAR - Indian Institute of Horticultural Research, Bengaluru, Karnataka, India
- Department of Agricultural Entomology, University of Agricultural Sciences, Bengaluru, Karnataka, India
| | - Pradeep Chalapathi
- Division of Basic Sciences, ICAR - Indian Institute of Horticultural Research, Bengaluru, Karnataka, India
- Department of Agricultural Entomology, University of Agricultural Sciences, Bengaluru, Karnataka, India
| | - Manamohan Maligeppagol
- Division of Basic Sciences, ICAR - Indian Institute of Horticultural Research, Bengaluru, Karnataka, India
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Seth RK, Yadav P, Reynolds SE. Dichotomous sperm in Lepidopteran insects: a biorational target for pest management. FRONTIERS IN INSECT SCIENCE 2023; 3:1198252. [PMID: 38469506 PMCID: PMC10926456 DOI: 10.3389/finsc.2023.1198252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/31/2023] [Indexed: 03/13/2024]
Abstract
Lepidoptera are unusual in possessing two distinct kinds of sperm, regular nucleated (eupyrene) sperm and anucleate (apyrene) sperm ('parasperm'). Sperm of both types are transferred to the female and are required for male fertility. Apyrene sperm play 'helper' roles, assisting eupyrene sperm to gain access to unfertilized eggs and influencing the reproductive behavior of mated female moths. Sperm development and behavior are promising targets for environmentally safer, target-specific biorational control strategies in lepidopteran pest insects. Sperm dimorphism provides a wide window in which to manipulate sperm functionality and dynamics, thereby impairing the reproductive fitness of pest species. Opportunities to interfere with spermatozoa are available not only while sperm are still in the male (before copulation), but also in the female (after copulation, when sperm are still in the male-provided spermatophore, or during storage in the female's spermatheca). Biomolecular technologies like RNAi, miRNAs and CRISPR-Cas9 are promising strategies to achieve lepidopteran pest control by targeting genes directly or indirectly involved in dichotomous sperm production, function, or persistence.
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Affiliation(s)
- Rakesh K. Seth
- Department of Zoology, University of Delhi, Delhi, India
| | - Priya Yadav
- Department of Zoology, University of Delhi, Delhi, India
| | - Stuart E. Reynolds
- Department of Life Sciences, University of Bath, Bath, United Kingdom
- Milner Centre for Evolution, University of Bath, Bath, United Kingdom
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