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Yadav P, Seth RK, Reynolds SE. A sperm-activating trypsin-like protease from the male reproductive tract of Spodoptera litura: Proteomic identification, sequence characterization, gene expression profile, RNAi and the effects of ionizing radiation. JOURNAL OF INSECT PHYSIOLOGY 2024; 156:104664. [PMID: 38897288 DOI: 10.1016/j.jinsphys.2024.104664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/15/2024] [Accepted: 06/16/2024] [Indexed: 06/21/2024]
Abstract
Like other lepidopteran insects, males of the tobacco cutworm moth, Spodoptera litura produce two kinds of spermatozoa, eupyrene (nucleate) and apyrene (anucleate) sperm. Formed in the testis, both kinds of sperm are released into the male reproductive tract in an immature form and are stored in the duplex region of the tract. Neither type of sperm is motile at this stage. When stored apyrene sperm from the duplex are treated in vitro with an extract of the prostatic region of the male tract, or with mammalian trypsin, they become motile; activation is greater and achieved more rapidly with increasing concentration of extract or enzyme. The activating effect of prostatic extract is blocked by soybean trypsin inhibitor (SBTI), also in a dose-dependent way. These results suggest that the normal sperm-activating process is due to an endogenous trypsin-like protease produced in the prostatic region. Proteomic analysis of S. litura prostatic extracts revealed a Trypsin-Like Serine Protease, TLSP, molecular weight 27 kDa, whose 199-residue amino acid sequence is identical to that of a predicted protein from the S. litura genome and is highly similar to predicted proteins encoded by genes in the genomes of several other noctuid moth species. Surprisingly, TLSP is only distantly related to Serine Protease 2 (initiatorin) of the silkmoth, Bombyx mori, the only identified lepidopteran protein so far shown to activate sperm. TLSP has features typical of secreted proteins, probably being synthesized as an inactive precursor zymogen, which is later activated by proteolytic cleavage. cDNA was synthesized from total RNA extracted from the prostatic region and was used to examine TLSP expression using qPCR. tlsp mRNA was expressed in both the prostatic region and the accessory glands of the male tract. Injection of TLSP-specific dsRNA into adult males caused a significant reduction after 24 h in tlsp mRNA levels in both locations. The number of eggs laid by females mated to adult males that were given TLSP dsRNA in 10 % honey solution, and the fertility (% hatched) of the eggs were reduced. Injecting pupae with TLSP dsRNA caused the later activation of apyrene sperm motility by adult male prostatic extracts to be significantly reduced compared to controls. Exposure of S. litura pupae to ionizing radiation significantly reduced expression of tlsp mRNA in the prostatic part and accessory gland of irradiated males in both the irradiated generation and also in their (unirradiated) F1 progeny. The implications of these findings for the use of the inherited sterility technique for the control of S. litura and other pest Lepidoptera are discussed.
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Affiliation(s)
- Priya Yadav
- Department of Zoology, University of Delhi, Delhi 110007, India.
| | - Rakesh K Seth
- Department of Zoology, University of Delhi, Delhi 110007, India.
| | - Stuart E Reynolds
- Department of Life Sciences, University of Bath, Bath BA2 7AY, UK; Milner Centre for Evolution, University of Bath, Bath BA2 7AY, UK.
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Grula CC, Rajamohan A, Rinehart JP. Monarch butterfly conservation through male germplasm cryopreservation. Sci Rep 2024; 14:14920. [PMID: 38942916 PMCID: PMC11213920 DOI: 10.1038/s41598-024-65624-x] [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: 02/05/2024] [Accepted: 06/21/2024] [Indexed: 06/30/2024] Open
Abstract
Monarch butterfly (Danaus plexippus L.) populations have declined in North America. The International Union for Conservation of Nature (IUCN) recently classified the species as endangered, sparking public concern and conservation efforts. Our approach to conservation is through cryopreservation of germinal cells and tissue. The goal of this study was to develop a cryopreservation protocol for monarch spermatozoa to ensure successful long-term storage. Cryopreserved sperm cells would provide a reserve of monarch germplasm, which could be utilized in the event of population loss. In this study, sperm cell bundles collected from male monarch butterflies were cryopreserved in a cryoprotective medium and stored in liquid nitrogen. To determine the post-cryopreservation sperm cell viability, a subsample of preserved sperm bundles were thawed rapidly, and their viability was qualified using a sperm live/dead stain. We are presenting a protocol to preserve and store genetic material and viable sperm bundles of the monarch butterfly. To date, this is the first report of successful cryopreservation of monarch germplasm which sets the foundation for cryostorage and could be extensible to other vulnerable lepidopterans.
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Affiliation(s)
- Courtney C Grula
- Insect Genetics and Biochemistry Edward T. Schafer Research Center, U.S. Department of Agriculture/Agricultural Research Center, 1616 Albrecht Boulevard, Fargo, ND, 58102, USA.
| | - Arun Rajamohan
- Insect Genetics and Biochemistry Edward T. Schafer Research Center, U.S. Department of Agriculture/Agricultural Research Center, 1616 Albrecht Boulevard, Fargo, ND, 58102, USA
| | - Joseph P Rinehart
- Insect Genetics and Biochemistry Edward T. Schafer Research Center, U.S. Department of Agriculture/Agricultural Research Center, 1616 Albrecht Boulevard, Fargo, ND, 58102, USA
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Sullivan W. Remarkable chromosomes and karyotypes: A top 10 list. Mol Biol Cell 2024; 35:pe1. [PMID: 38517328 PMCID: PMC11064663 DOI: 10.1091/mbc.e23-12-0498] [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: 12/20/2023] [Revised: 02/23/2024] [Accepted: 03/01/2024] [Indexed: 03/23/2024] Open
Abstract
Chromosomes and karyotypes are particularly rich in oddities and extremes. Described below are 10 remarkable chromosomes and karyotypes sprinkled throughout the tree of life. These include variants in chromosome number, structure, and dynamics both natural and engineered. This versatility highlights the robustness and tolerance of the mitotic and meiotic machinery to dramatic changes in chromosome and karyotype architecture. These examples also illustrate that the robustness comes at a cost, enabling the evolution of chromosomes that subvert mitosis and meiosis.
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Affiliation(s)
- William Sullivan
- Department of MCD Biology, University of California, Santa Cruz, CA 95064
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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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Sakakura M, Takata Y, Kimura C, Matsuda S, Takamura T, Nagaoka S. Limited proteolysis by a prostatic endopeptidase, the sperm-activating factor initiatorin, regulates the activation of pro-carboxypeptidase B in the seminal fluid of the silkworm, Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 148:103819. [PMID: 35963292 DOI: 10.1016/j.ibmb.2022.103819] [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: 08/03/2021] [Revised: 07/31/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
A prostate trypsin-like serine endopeptidase called initiatorin (BmIni) is an essential factor in triggering the sperm maturation response of the silkworm, Bombyx mori. BmIni has been predicted to specifically cleave the carboxyl side of two consecutive arginine residues present in certain seminal plasma and sperm proteins, but the actual substrates are still unknown. In an attempt to elucidate the molecular mechanism underlying the sperm maturation signaling pathway, in this study, we examined whether BmIni activates the seminal carboxypeptidase B (BmCPB) protein through specific degradation. First, we confirmed in vitro that the inactive BmCPB present in unmated male vesicula (v.) seminalis is activated by treatment with BmIni or trypsin. Molecular cloning of the gene encoding the seminal BmCPB protein has shown that BmCPB is produced as a secreted proenzyme and may be activated after a trypsin-like protease cleaves the boundary between the prodomain and the enzyme site. In support of these findings, both trypsin and BmIni significantly activated recombinant Pro-BmCPB, which was successfully expressed and purified as a proenzyme in Escherichia coli; moreover, two specific cleavage forms appeared in the activation by BmIni that did not appear in that by trypsin. Therefore, a recombinant protein with a mutated diarginine motif (Arg109-Arg110), which is presumed to be a pre-cleavage site of BmCPB based on its high homology with bovine CPB, was prepared and treated with BmIni. As a result, the two specific degraded peptides were no longer observed, and simultaneously the activation was suppressed. Taken together, these findings lead to the conclusion that zymogen BmCPB, which is synthesized and secreted in male reproductive organs, is activated by sequence-dependent proteolysis by BmIni during ejaculation and in the female reproductive organs, providing a clue to the mechanism underlying seminal plasma and/or sperm protein degradation by BmIni in the sperm maturation cascade of B. mori.
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Affiliation(s)
- Miki Sakakura
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Yuki Takata
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Chikayo Kimura
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Saki Matsuda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Tomoko Takamura
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Sumiharu Nagaoka
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan; Center for Bioresource Field Sciences, Kyoto Institute of Technology, 1 Saga-ippongi-cho, Ukyo-ku, Kyoto, 616-8354, Japan.
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Go AC, Civetta A. Divergence of X-linked trans regulatory proteins and the misexpression of gene targets in sterile Drosophila pseudoobscura hybrids. BMC Genomics 2022; 23:30. [PMID: 34991488 PMCID: PMC8740060 DOI: 10.1186/s12864-021-08267-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The genetic basis of hybrid incompatibilities is characterized by pervasive cases of gene interactions. Sex chromosomes play a major role in speciation and X-linked hybrid male sterility (HMS) genes have been identified. Interestingly, some of these genes code for proteins with DNA binding domains, suggesting a capability to act as trans-regulatory elements and disturb the expression of a large number of gene targets. To understand how interactions between trans- and cis-regulatory elements contribute to speciation, we aimed to map putative X-linked trans-regulatory elements and to identify gene targets with disrupted gene expression in sterile hybrids between the subspecies Drosophila pseudoobscura pseudoobscura and D. p. bogotana. RESULTS We find six putative trans-regulatory proteins within previously mapped X chromosome HMS loci with sequence changes that differentiate the two subspecies. Among them, the previously characterized HMS gene Overdrive (Ovd) had the largest number of amino acid changes between subspecies, with some substitutions localized within the protein's DNA binding domain. Using an introgression approach, we detected transcriptional responses associated with a sterility/fertility Ovd allele swap. We found a network of 52 targets of Ovd and identified cis-regulatory effects among target genes with disrupted expression in sterile hybrids. However, a combined analysis of polymorphism and divergence in non-coding sequences immediately upstream of target genes found no evidence of changes in candidate regulatory proximal cis-elements. Finally, peptidases were over-represented among target genes. CONCLUSIONS We provide evidence of divergence between subspecies within the DNA binding domain of the HMS protein Ovd and identify trans effects on the expression of 52 gene targets. Our results identify a network of trans-cis interactions with possible effects on HMS. This network provides molecular evidence of gene × gene incompatibilities as contributors to hybrid dysfunction.
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Affiliation(s)
- Alwyn C Go
- Department of Biology, University of Winnipeg, 515 Portage Ave, Winnipeg, MB, R3B 2E9, Canada
| | - Alberto Civetta
- Department of Biology, University of Winnipeg, 515 Portage Ave, Winnipeg, MB, R3B 2E9, Canada.
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