1
|
Harumoto T. Self-stabilization mechanism encoded by a bacterial toxin facilitates reproductive parasitism. Curr Biol 2023; 33:4021-4029.e6. [PMID: 37673069 DOI: 10.1016/j.cub.2023.08.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/30/2023] [Accepted: 08/10/2023] [Indexed: 09/08/2023]
Abstract
A wide variety of maternally transmitted endosymbionts in insects are associated with reproductive parasitism, whereby they interfere with host reproduction to increase the ratio of infected females and spread within populations.1,2 Recent successes in identifying bacterial factors responsible for reproductive parasitism3,4,5,6,7 as well as further omics approaches8,9,10,11,12 have highlighted the common appearance of deubiquitinase domains, although their biological roles-in particular, how they link to distinct manipulative phenotypes-remain poorly defined. Spiroplasma poulsonii is a helical and motile bacterial endosymbiont of Drosophila,13,14 which selectively kills male progeny with a male-killing toxin Spaid (S. poulsonii androcidin), which encodes an ovarian tumor (OTU) deubiquitinase domain.6 Artificial expression of Spaid in flies reproduces male-killing-associated pathologies that include abnormal apoptosis and neural defects during embryogenesis6,15,16,17,18,19; moreover, it highly accumulates on the dosage-compensated male X chromosome,20 congruent with cellular defects such as the DNA damage/chromatin bridge breakage specifically induced upon that chromosome.6,21,22,23 Here, I show that without the function of OTU, Spaid is polyubiquitinated and degraded through the host ubiquitin-proteasome pathway, leading to the attenuation of male-killing activity as shown previously.6 Furthermore, I find that Spaid utilizes its OTU domain to deubiquitinate itself in an intermolecular manner. Collectively, the deubiquitinase domain of Spaid serves as a self-stabilization mechanism to facilitate male killing in flies, optimizing a molecular strategy of endosymbionts that enables the efficient manipulation of the host at a low energetic cost.
Collapse
Affiliation(s)
- Toshiyuki Harumoto
- Hakubi Center for Advanced Research, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan; Graduate School of Biostudies, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
| |
Collapse
|
2
|
Alarcón ME, Polo PG, Akyüz SN, Rafiqi AM. Evolution and ontogeny of bacteriocytes in insects. Front Physiol 2022; 13:1034066. [PMID: 36505058 PMCID: PMC9732443 DOI: 10.3389/fphys.2022.1034066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/11/2022] [Indexed: 11/26/2022] Open
Abstract
The ontogenetic origins of the bacteriocytes, which are cells that harbour bacterial intracellular endosymbionts in multicellular animals, are unknown. During embryonic development, a series of morphological and transcriptional changes determine the fate of distinct cell types. The ontogeny of bacteriocytes is intimately linked with the evolutionary transition of endosymbionts from an extracellular to an intracellular environment, which in turn is linked to the diet of the host insect. Here we review the evolution and development of bacteriocytes in insects. We first classify the endosymbiotic occupants of bacteriocytes, highlighting the complex challenges they pose to the host. Then, we recall the historical account of the discovery of bacteriocytes. We then summarize the molecular interactions between the endosymbiont and the host. In addition, we illustrate the genetic contexts in which the bacteriocytes develop, with examples of the genetic changes in the hosts and endosymbionts, during specific endosymbiotic associations. We finally address the evolutionary origin as well as the putative ontogenetic or developmental source of bacteriocytes in insects.
Collapse
|
3
|
Hornett EA, Kageyama D, Hurst GDD. Sex determination systems as the interface between male-killing bacteria and their hosts. Proc Biol Sci 2022; 289:20212781. [PMID: 35414231 PMCID: PMC9005997 DOI: 10.1098/rspb.2021.2781] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/14/2022] [Indexed: 12/17/2022] Open
Abstract
Arthropods host a range of sex-ratio-distorting selfish elements, including diverse maternally inherited endosymbionts that solely kill infected males. Male-killing heritable microbes are common, reach high frequency, but until recently have been poorly understood in terms of the host-microbe interaction. Additionally, while male killing should generate strong selection for host resistance, evidence of this has been scant. The interface of the microbe with host sex determination is integral to the understanding of how death is sex limited and how hosts can evolve evasion of male killing. We first review current knowledge of the mechanisms diverse endosymbionts use to induce male-specific death. We then examine recent evidence that these agents do produce intense selection for host nuclear suppressor elements. We argue, from our understanding of male-killing mechanisms, that suppression will commonly involve evolution of the host sex determination pathways and that the host's response to male-killing microbes thus represents an unrecognized driver of the diversity of arthropod sex determination. Further work is required to identify the genes and mechanisms responsible for male-killing suppression, which will both determine the components of sex determination (or other) systems associated with suppressor evolution, and allow insight into the mechanism of male killing itself.
Collapse
Affiliation(s)
- Emily A. Hornett
- Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Biosciences Building, Liverpool L69 7ZB, UK
- Vector Biology, LSTM, Liverpool L3 5QA, UK
| | | | - Gregory D. D. Hurst
- Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Biosciences Building, Liverpool L69 7ZB, UK
| |
Collapse
|
4
|
Mateos M, Silva NO, Ramirez P, Higareda-Alvear VM, Aramayo R, Erickson JW. Effect of heritable symbionts on maternally-derived embryo transcripts. Sci Rep 2019; 9:8847. [PMID: 31222094 PMCID: PMC6586653 DOI: 10.1038/s41598-019-45371-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 05/28/2019] [Indexed: 11/09/2022] Open
Abstract
Maternally-transmitted endosymbiotic bacteria are ubiquitous in insects. Among other influential phenotypes, many heritable symbionts of arthropods are notorious for manipulating host reproduction through one of four reproductive syndromes, which are generally exerted during early developmental stages of the host: male feminization; parthenogenesis induction; male killing; and cytoplasmic incompatibility (CI). Major advances have been achieved in understanding mechanisms and identifying symbiont factors involved in reproductive manipulation, particularly male killing and cytoplasmic incompatibility. Nonetheless, whether cytoplasmically-transmitted bacteria influence the maternally-loaded components of the egg or early embryo has not been examined. In the present study, we investigated whether heritable endosymbionts that cause different reproductive phenotypes in Drosophila melanogaster influence the mRNA transcriptome of early embryos. We used mRNA-seq to evaluate differential expression in Drosophila embryos lacking endosymbionts (control) to those harbouring the male-killing Spiroplasma poulsonii strain MSRO-Br, the CI-inducing Wolbachia strain wMel, or Spiroplasma poulsonii strain Hyd1; a strain that lacks a reproductive phenotype and is naturally associated with Drosophila hydei. We found no consistent evidence of influence of symbiont on mRNA composition of early embryos, suggesting that the reproductive manipulation mechanism does not involve alteration of maternally-loaded transcripts. In addition, we capitalized on several available mRNA-seq datasets derived from Spiroplasma-infected Drosophila melanogaster embryos, to search for signals of depurination of rRNA, consistent with the activity of Ribosome Inactivating Proteins (RIPs) encoded by Spiroplasma poulsonii. We found small but statistically significant signals of depurination of Drosophila rRNA in the Spiroplasma treatments (both strains), but not in the symbiont-free control or Wolbachia treatment, consistent with the action of RIPs. The depurination signal was slightly stronger in the treatment with the male-killing strain. This result supports a recent report that RIP-induced damage contributes to male embryo death.
Collapse
Affiliation(s)
- Mariana Mateos
- Department Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA.
| | - Nadisha O Silva
- Department Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA
- Department Biology, Texas A&M University, College Station, TX, USA
| | - Paulino Ramirez
- Department Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA
| | - Victor M Higareda-Alvear
- Centro de Ciencias Genómicas (CCG), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Rodolfo Aramayo
- Department Biology, Texas A&M University, College Station, TX, USA
| | - James W Erickson
- Department Biology, Texas A&M University, College Station, TX, USA
| |
Collapse
|
5
|
Harumoto T, Fukatsu T, Lemaitre B. Common and unique strategies of male killing evolved in two distinct Drosophila symbionts. Proc Biol Sci 2019; 285:rspb.2017.2167. [PMID: 29563258 DOI: 10.1098/rspb.2017.2167] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 02/26/2018] [Indexed: 11/12/2022] Open
Abstract
Male killing is a selfish reproductive manipulation caused by symbiotic bacteria, where male offspring of infected hosts are selectively killed. The underlying mechanisms and the process of their evolution are of great interest not only in terms of fundamental biology, but also their potential applications. The two bacterial Drosophila symbionts, Wolbachia and Spiroplasma, have independently evolved male-killing ability. This raises the question whether the underlying mechanisms share some similarities or are specific to each bacterial species. Here, we analyse pathogenic phenotypes of D. bifasciata infected with its natural male-killing Wolbachia strain and compare them with those of D. melanogaster infected with male-killing Spiroplasma We show that male progeny infected with the Wolbachia strain die during embryogenesis with abnormal apoptosis. Interestingly, male-killing Wolbachia infection induces DNA damage and segregation defects in the dosage-compensated chromosome in male embryos, which are reminiscent of the phenotypes caused by male-killing Spiroplasma in D. melanogaster By contrast, host neural development seems to proceed normally unlike male-killing Spiroplasma infection. Our results demonstrate that the dosage-compensated chromosome is a common target of two distinct male killers, yet Spiroplasma uniquely evolved the ability to damage neural tissue of male embryos.
Collapse
Affiliation(s)
- Toshiyuki Harumoto
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
| | - Takema Fukatsu
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Japan
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
| |
Collapse
|
6
|
Abstract
Several lineages of symbiotic bacteria in insects selfishly manipulate host reproduction to spread in a population 1 , often by distorting host sex ratios. Spiroplasma poulsonii2,3 is a helical and motile, Gram-positive symbiotic bacterium that resides in a wide range of Drosophila species 4 . A notable feature of S. poulsonii is male killing, whereby the sons of infected female hosts are selectively killed during development1,2. Although male killing caused by S. poulsonii has been studied since the 1950s, its underlying mechanism is unknown. Here we identify an S. poulsonii protein, designated Spaid, whose expression induces male killing. Overexpression of Spaid in D. melanogaster kills males but not females, and induces massive apoptosis and neural defects, recapitulating the pathology observed in S. poulsonii-infected male embryos5-11. Our data suggest that Spaid targets the dosage compensation machinery on the male X chromosome to mediate its effects. Spaid contains ankyrin repeats and a deubiquitinase domain, which are required for its subcellular localization and activity. Moreover, we found a laboratory mutant strain of S. poulsonii with reduced male-killing ability and a large deletion in the spaid locus. Our study has uncovered a bacterial protein that affects host cellular machinery in a sex-specific way, which is likely to be the long-searched-for factor responsible for S. poulsonii-induced male killing.
Collapse
|
7
|
Male-killing symbiont damages host's dosage-compensated sex chromosome to induce embryonic apoptosis. Nat Commun 2016; 7:12781. [PMID: 27650264 PMCID: PMC5036004 DOI: 10.1038/ncomms12781] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/01/2016] [Indexed: 12/02/2022] Open
Abstract
Some symbiotic bacteria are capable of interfering with host reproduction in selfish ways. How such bacteria can manipulate host's sex-related mechanisms is of fundamental interest encompassing cell, developmental and evolutionary biology. Here, we uncover the molecular and cellular mechanisms underlying Spiroplasma-induced embryonic male lethality in Drosophila melanogaster. Transcriptomic analysis reveals that many genes related to DNA damage and apoptosis are up-regulated specifically in infected male embryos. Detailed genetic and cytological analyses demonstrate that male-killing Spiroplasma causes DNA damage on the male X chromosome interacting with the male-specific lethal (MSL) complex. The damaged male X chromosome exhibits a chromatin bridge during mitosis, and bridge breakage triggers sex-specific abnormal apoptosis via p53-dependent pathways. Notably, the MSL complex is not only necessary but also sufficient for this cytotoxic process. These results highlight symbiont's sophisticated strategy to target host's sex chromosome and recruit host's molecular cascades toward massive apoptosis in a sex-specific manner. Symbiotic bacteria are able to interfere with host reproduction in ways that are detrimental to the host organism. Here the authors show that Spiroplasma induces DNA damage on the male X chromosome in Drosophila, causing sex-specific apoptosis.
Collapse
|
8
|
Hurst GDD, Frost CL. Reproductive parasitism: maternally inherited symbionts in a biparental world. Cold Spring Harb Perspect Biol 2015; 7:a017699. [PMID: 25934011 PMCID: PMC4448626 DOI: 10.1101/cshperspect.a017699] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Most species of insect, and many other plants and animals, carry maternally heritable microorganisms-viruses, bacteria, unicellular eukaryotes, and fungi that pass from a female host to her progeny. Maternal inheritance establishes a correlation between the fitness of symbiont and host female, which can select for the symbiont to contribute to host fitness. Nevertheless, its lack of transmission through male hosts places the symbiont in conflict with biparentally inherited nuclear genes. In this review, we first examine how this conflict is manifest in selection to promote the production and survival of infected female hosts and gametes. We then examine how the distorted population sex ratios that they produce may affect host reproductive ecology, and thus the intensity of other conflicts associated with sexual reproduction. Finally, we examine evolved host responses to symbiont manipulation. We argue that the unusual intensity of symbiont-host conflict generates extreme selection pressures that can drive changes in sex-determination systems, the basic pathway through which males and females are constructed.
Collapse
Affiliation(s)
- Gregory D D Hurst
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Crystal L Frost
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| |
Collapse
|
9
|
Male-killing Spiroplasma induces sex-specific cell death via host apoptotic pathway. PLoS Pathog 2014; 10:e1003956. [PMID: 24550732 PMCID: PMC3923752 DOI: 10.1371/journal.ppat.1003956] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 01/12/2014] [Indexed: 11/19/2022] Open
Abstract
Some symbiotic bacteria cause remarkable reproductive phenotypes like cytoplasmic incompatibility and male-killing in their host insects. Molecular and cellular mechanisms underlying these symbiont-induced reproductive pathologies are of great interest but poorly understood. In this study, Drosophila melanogaster and its native Spiroplasma symbiont strain MSRO were investigated as to how the host's molecular, cellular and morphogenetic pathways are involved in the symbiont-induced male-killing during embryogenesis. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining, anti-cleaved-Caspase-3 antibody staining, and apoptosis-deficient mutant analysis unequivocally demonstrated that the host's apoptotic pathway is involved in Spiroplasma-induced male-specific embryonic cell death. Double-staining with TUNEL and an antibody recognizing epidermal marker showed that embryonic epithelium is the main target of Spiroplasma-induced male-specific apoptosis. Immunostaining with antibodies against markers of differentiated and precursor neural cells visualized severe neural defects specifically in Spiroplasma-infected male embryos as reported in previous studies. However, few TUNEL signals were detected in the degenerate nervous tissues of male embryos, and the Spiroplasma-induced neural defects in male embryos were not suppressed in an apoptosis-deficient host mutant. These results suggest the possibility that the apoptosis-dependent epidermal cell death and the apoptosis-independent neural malformation may represent different mechanisms underlying the Spiroplasma-induced male-killing. Despite the male-specific progressive embryonic abnormality, Spiroplasma titers remained almost constant throughout the observed stages of embryonic development and across male and female embryos. Strikingly, a few Spiroplasma-infected embryos exhibited gynandromorphism, wherein apoptotic cell death was restricted to male cells. These observations suggest that neither quantity nor proliferation of Spiroplasma cells but some Spiroplasma-derived factor(s) may be responsible for the expression of the male-killing phenotype. Symbiotic bacteria are ubiquitously associated with diverse insects, and affect their host biology in a variety of ways. In Drosophila fruit flies, infection with Spiroplasma symbionts often causes male-specific embryonic mortality, resulting in the production of all-female offspring. This striking phenotype is called “male-killing”, whose underlying mechanisms are of great interest. Here we investigated Drosophila melanogaster and its native Spiroplasma symbiont strain to understand how the host's molecular, cellular and morphogenetic pathways are involved in the symbiont-induced male-killing. Specifically in Spiroplasma-infected male embryos, pathogenic phenotypes including massive cell death throughout the body and neural malformation were observed. We unequivocally identified that the male-specific cell death preferentially occurs in the embryonic epithelium via the host's apoptotic pathway. Meanwhile, we found that, unexpectedly, the male-specific neural defects occur independently of host's apoptosis, suggesting that at least two different mechanisms may be involved in the Spiroplasma-induced male-killing. Also unexpected was the finding that Spiroplasma titers are almost constant throughout embryogenesis irrespective of sex despite the male-specific severe apoptosis. We serendipitously found Spiroplasma-infected sexual mosaic embryos, wherein apoptosis was associated with male cells, which suggests that some Spiroplasma-derived factor(s) may selectively act on male cells and cause male-killing.
Collapse
|
10
|
Martin J, Chong T, Ferree PM. Male killing Spiroplasma preferentially disrupts neural development in the Drosophila melanogaster embryo. PLoS One 2013; 8:e79368. [PMID: 24236124 PMCID: PMC3827344 DOI: 10.1371/journal.pone.0079368] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 09/29/2013] [Indexed: 11/23/2022] Open
Abstract
Male killing bacteria such as Spiroplasma are widespread pathogens of numerous arthropods including Drosophila melanogaster. These maternally transmitted bacteria can bias host sex ratios toward the female sex in order to ‘selfishly’ enhance bacterial transmission. However, little is known about the specific means by which these pathogens disrupt host development in order to kill males. Here we show that a male-killing Spiroplasma strain severely disrupts nervous tissue development in male but not female D. melanogaster embryos. The neuroblasts, or neuron progenitors, form properly and their daughter cells differentiate into neurons of the ventral nerve chord. However, the neurons fail to pack together properly and they produce highly abnormal axons. In contrast, non-neural tissue, such as mesoderm, and body segmentation appear normal during this time, although the entire male embryo becomes highly abnormal during later stages. Finally, we found that Spiroplasma is altogether absent from the neural tissue but localizes within the gut and the epithelium immediately surrounding the neural tissue, suggesting that the bacterium secretes a toxin that affects neural tissue development across tissue boundaries. Together these findings demonstrate the unique ability of this insect pathogen to preferentially affect development of a specific embryonic tissue to induce male killing.
Collapse
Affiliation(s)
- Jennifer Martin
- W. M. Keck Science Department, Claremont McKenna, Scripps, and Pitzer Colleges, Claremont, California, United States of America
| | - Trisha Chong
- W. M. Keck Science Department, Claremont McKenna, Scripps, and Pitzer Colleges, Claremont, California, United States of America
| | - Patrick M. Ferree
- W. M. Keck Science Department, Claremont McKenna, Scripps, and Pitzer Colleges, Claremont, California, United States of America
- * E-mail:
| |
Collapse
|
11
|
Duplouy A, Iturbe-Ormaetxe I, Beatson SA, Szubert JM, Brownlie JC, McMeniman CJ, McGraw EA, Hurst GDD, Charlat S, O'Neill SL, Woolfit M. Draft genome sequence of the male-killing Wolbachia strain wBol1 reveals recent horizontal gene transfers from diverse sources. BMC Genomics 2013; 14:20. [PMID: 23324387 PMCID: PMC3639933 DOI: 10.1186/1471-2164-14-20] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 01/02/2013] [Indexed: 02/06/2023] Open
Abstract
Background The endosymbiont Wolbachia pipientis causes diverse and sometimes dramatic phenotypes in its invertebrate hosts. Four Wolbachia strains sequenced to date indicate that the constitution of the genome is dynamic, but these strains are quite divergent and do not allow resolution of genome diversification over shorter time periods. We have sequenced the genome of the strain wBol1-b, found in the butterfly Hypolimnas bolina, which kills the male offspring of infected hosts during embyronic development and is closely related to the non-male-killing strain wPip from Culex pipiens. Results The genomes of wBol1-b and wPip are similar in genomic organisation, sequence and gene content, but show substantial differences at some rapidly evolving regions of the genome, primarily associated with prophage and repetitive elements. We identified 44 genes in wBol1-b that do not have homologs in any previously sequenced strains, indicating that Wolbachia’s non-core genome diversifies rapidly. These wBol1-b specific genes include a number that have been recently horizontally transferred from phylogenetically distant bacterial taxa. We further report a second possible case of horizontal gene transfer from a eukaryote into Wolbachia. Conclusions Our analyses support the developing view that many endosymbiotic genomes are highly dynamic, and are exposed and receptive to exogenous genetic material from a wide range of sources. These data also suggest either that this bacterial species is particularly permissive for eukaryote-to-prokaryote gene transfers, or that these transfers may be more common than previously believed. The wBol1-b-specific genes we have identified provide candidates for further investigations of the genomic bases of phenotypic differences between closely-related Wolbachia strains.
Collapse
Affiliation(s)
- Anne Duplouy
- School of Biological Sciences, University of Queensland, 4072, Brisbane, QLD, Australia.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Silva NO, Guenther LL, Xie J, Mateos M. Infection densities of three Spiroplasma strains in the host Drosophila melanogaster. Symbiosis 2012. [DOI: 10.1007/s13199-012-0181-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
13
|
Insect Sex Determination Manipulated by Their Endosymbionts: Incidences, Mechanisms and Implications. INSECTS 2012; 3:161-99. [PMID: 26467955 PMCID: PMC4553623 DOI: 10.3390/insects3010161] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 01/14/2012] [Accepted: 02/02/2012] [Indexed: 11/16/2022]
Abstract
The sex-determining systems of arthropods are surprisingly diverse. Some species have male or female heterogametic sex chromosomes while other species do not have sex chromosomes. Most species are diploids but some species, including wasps, ants, thrips and mites, are haplodiploids (n in males; 2n in females). Many of the sexual aberrations, such as sexual mosaics, sex-specific lethality and conversion of sexuality, can be explained by developmental defects including double fertilization of a binucleate egg, loss of a sex chromosome or perturbation of sex-determining gene expression, which occur accidentally or are induced by certain environmental conditions. However, recent studies have revealed that such sexual aberrations can be caused by various groups of vertically-transmitted endosymbiotic microbes such as bacteria of the genera Wolbachia, Rickettsia, Arsenophonus, Spiroplasma and Cardinium, as well as microsporidian protists. In this review, we first summarize the accumulated data on endosymbiont-induced sexual aberrations, and then discuss how such endosymbionts affect the developmental system of their hosts and what kinds of ecological and evolutionary effects these endosymbionts have on their host populations.
Collapse
|
14
|
Riparbelli MG, Giordano R, Ueyama M, Callaini G. Wolbachia-mediated male killing is associated with defective chromatin remodeling. PLoS One 2012; 7:e30045. [PMID: 22291901 PMCID: PMC3264553 DOI: 10.1371/journal.pone.0030045] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 12/08/2011] [Indexed: 11/19/2022] Open
Abstract
Male killing, induced by different bacterial taxa of maternally inherited microorganisms, resulting in highly distorted female-biased sex-ratios, is a common phenomenon among arthropods. Some strains of the endosymbiont bacteria Wolbachia have been shown to induce this phenotype in particular insect hosts. High altitude populations of Drosophila bifasciata infected with Wolbachia show selective male killing during embryonic development. However, since this was first reported, circa 60 years ago, the interaction between Wolbachia and its host has remained unclear. Herein we show that D. bifasciata male embryos display defective chromatin remodeling, improper chromatid segregation and chromosome bridging, as well as abnormal mitotic spindles and gradual loss of their centrosomes. These defects occur at different times in the early development of male embryos leading to death during early nuclear division cycles or large defective areas of the cellular blastoderm, culminating in abnormal embryos that die before eclosion. We propose that Wolbachia affects the development of male embryos by specifically targeting male chromatin remodeling and thus disturbing mitotic spindle assembly and chromosome behavior. These are the first observations that demonstrate fundamental aspects of the cytological mechanism of male killing and represent a solid base for further molecular studies of this phenomenon.
Collapse
Affiliation(s)
| | - Rosanna Giordano
- Illinois Natural History Survey, Institute of Natural Resource Sustainability, University of Illinois at Urbana-Champaign, Champaign, Illinois, United States of America
| | - Morio Ueyama
- Laboratory of Cell Biology, Department of Bioinformatics, Soka University, Hachioji, Tokyo, Japan
| | - Giuliano Callaini
- Department of Evolutionary Biology, University of Siena, Siena, Italy
- * E-mail:
| |
Collapse
|
15
|
Sugimoto TN, Ishikawa Y. A male-killing Wolbachia carries a feminizing factor and is associated with degradation of the sex-determining system of its host. Biol Lett 2012; 8:412-5. [PMID: 22219393 PMCID: PMC3367752 DOI: 10.1098/rsbl.2011.1114] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Endosymbiotic bacteria of the genus Wolbachia induce diverse reproductive alterations in their insect hosts. Wolbachia (wSca) infecting the moth Ostrinia scapulalis causes unusual male killing, in which males (genotype: ZZ) selectively die during embryonic and larval development, whereas females (genotype: ZW), in turn, selectively die when cured of infection. To gain insight into the interaction between wSca and the host, we analysed phenotypic and genetic sexes of the embryos and larvae of normal, wSca-infected, and infected-and-cured O. scapulalis by diagnosing the sex-specifically spliced transcripts of Osdsx-a homologue of the sex-determining gene doublesex-and sex chromatin in interphase nuclei, respectively. It was observed that the female-type Osdsx was expressed in the infected male (ZZ) progenies destined to die, whereas the male-type Osdsx was expressed in the cured female (ZW) progenies destined to die. These findings suggest that (i) wSca, a male killer, carries a genetic factor that feminizes the male host, (ii) the sex-determining system of the host is degraded, and (iii) a mismatch between the genetic and phenotypic sexes underlies the sex-specific death.
Collapse
Affiliation(s)
- Takafumi N Sugimoto
- Graduate School of Agricultural and Life Sciences, Department of Agriculture and Environmental Biology, The University of Tokyo, Tokyo, Japan
| | | |
Collapse
|
16
|
Phenotype and transmission efficiency of artificial and natural male-killing Spiroplasma infections in Drosophila melanogaster. J Invertebr Pathol 2011; 109:243-7. [PMID: 22085686 DOI: 10.1016/j.jip.2011.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 09/28/2011] [Accepted: 10/03/2011] [Indexed: 11/22/2022]
Abstract
Many insect species carry inherited Spiroplasma bacteria which act as important partners and antagonists. The nature of symbioses between Spiroplasma and insects has been most extensively studied in the interaction between male-killing Spiroplasma infection and Drosophila melanogaster. For historical reasons, these studies have largely focussed on the Spiroplasma strain known as NSRO, derived from Drosophila nebulosa and transinfected into D. melanogaster. More recently, D. melanogaster naturally infected with Spiroplasma were discovered. Whilst the well studied strain NSRO is closely related to that found natively in D. melanogaster, it is unclear whether strains from D. nebulosa reflect a natural interaction when placed in D. melanogaster. In this paper, we determine if NSRO has similar or different properties from strains of Spiroplasma naturally infecting D. melanogaster in terms of transmission efficiency and the strength and timing of male-killing. Native infections were observed to have higher transmission efficiency than introduced NSRO infections during the early phases of host reproduction, but not during late reproduction. The timing and intensity of male-killing did not differ between infection classes. As a precautionary measure, it is proposed that future work seeking to reveal the nature of coevolved Spiroplasma-Drosophila interactions use the native strain.
Collapse
|
17
|
Negri I, Pellecchia M, Grève P, Daffonchio D, Bandi C, Alma A. Sex and stripping: The key to the intimate relationship between Wolbachia and host? Commun Integr Biol 2011; 3:110-5. [PMID: 20585501 DOI: 10.4161/cib.3.2.10520] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Accepted: 11/03/2009] [Indexed: 11/19/2022] Open
Abstract
Wolbachia pipientis is known to infect only arthropods and nematodes (mainly filarial worms). A unique feature shared by the two Phyla is the ability to replace the exoskeleton, a process known as ecdysis. This shared characteristic is thought to reflect a common ancestry. Arthropod moulting is induced by the steroid hormone 20-hydroxyecdysone (20E) and a role for ecdysteroids in nematode ecdysis has also been suggested. Removing Wolbachia from filarial worms impairs the host's development. From analyses of the genome of Wolbachia harbored by the filarial nematode Brugia malayi and that of its host, the bacterium may provide a source of heme, an essential component of cytochrome P450's that are necessary for steroid hormone biosynthetic pathways.In arthropods, Wolbachia is a reproductive manipulator, inducing various phenotypic effects that may be due to differences in host physiology, in particular, endocrine-related processes governing development and reproduction. Insect steroids have well-defined roles in the coordination of multiple developmental processes, and in adults they control important aspects of reproduction, including ovarian development, oogenesis, sexual behavior, and in some taxa vitellogenin biosynthesis.According to some authors ecdysteroids may also act as sex hormones. In insects sex differentiation is generally thought to be a strictly genetic process, in which each cell decides its own sexual fate based on its sex chromosome constitution, but, surprisingly, recent data demonstrate that in Drosophila sex determination is not cell-autonomous, as it happens in mammals. Thus the presence of signals coordinating the development of a gender-specific phenotype cannot be excluded.This could explain why Wolbachia interferes with insect reproduction; and also could explain why Wolbachia interferes with insect development.Thus, is "sex (=reproduction) and stripping (=ecdysis)" the key to the intimate relationship between Wolbachia and its host?
Collapse
|
18
|
Anbutsu H, Fukatsu T. Spiroplasma as a model insect endosymbiont. ENVIRONMENTAL MICROBIOLOGY REPORTS 2011; 3:144-53. [PMID: 23761245 DOI: 10.1111/j.1758-2229.2010.00240.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Members of the genus Spiroplasma are actively motile and helical bacteria of the class Mollicutes, which are associated with a variety of arthropods and plants. Some spiroplasmas cause female-biased sex ratios of their host insects as a result of selective death of the male offspring during embryogenesis. Several strains of male-killing spiroplasmas have been successfully transfected into Drosophila melanogaster by haemolymph injection and maintained in laboratory fly stocks. Spiroplasma-Drosophila endosymbiosis represents an ideal model system for analysing the molecular mechanisms underlying host-symbiont interactions. The infection dynamics exhibited by the symbiont within the host, the effects of external and environmental factors on the symbiotic association and symbiont interactions with the host's immune system have been investigated using this system. Comparisons between a male-killing Spiroplasma strain and its non-male-killing variant revealed that, in addition to different male-killing abilities, they also differed in infection dynamics and resistance to host innate immunity. It is currently unclear whether these different phenotypes are interconnected to each other. However, if so, such pleiotropy could facilitate our understanding of the genetic and molecular mechanisms of the endosymbiotic system.
Collapse
Affiliation(s)
- Hisashi Anbutsu
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Japan
| | | |
Collapse
|
19
|
Hutchence KJ, Fischer B, Paterson S, Hurst GDD. How do insects react to novel inherited symbionts? A microarray analysis of Drosophila melanogaster response to the presence of natural and introduced Spiroplasma. Mol Ecol 2011; 20:950-8. [PMID: 21255169 DOI: 10.1111/j.1365-294x.2010.04974.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Maternally inherited endosymbionts are found in numerous insect species and have various effects on host ecology. New symbioses are most commonly established following lateral transfer of an existing symbiont from one host species to another. Laboratory study has demonstrated that symbionts commonly perform poorly in novel hosts, with weak vertical transmission and maladaptive pathogenicity being observed in the generations following transfer. This poor performance probably limits symbiont occurrence. We here use microarray technology to test whether poor symbiont performance observed following 1 year of vertical transmission through a new host is associated with alteration in host gene expression or whether it occurs independently of this. We utilize the Drosophila melanogaster--Spiroplasma interaction and test the response of the host in the presence of both natural Spiroplasma infections and novel Spiroplasma infections transinfected previously from other host species. None of the Spiroplasma infections investigated produced upregulation in host haemolymph/fat body-based immune responses, and we therefore rejected the hypothesis that failure to thrive was associated with immune upregulation. One infection was associated with a downregulation of genes associated with egg production compared to uninfected controls, indicative of damage to the host. The Spiroplasma infection showed that the weakest vertical transmission showed no significant disturbance to host gene expression compared to uninfected controls. We conclude that the failure of Spiroplasma in novel host species is associated either with causing harm to their new hosts or through a failure to thrive in the new host that occurs independently of host responses to infection.
Collapse
Affiliation(s)
- Kate J Hutchence
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, Merseyside L69 7ZB, UK
| | | | | | | |
Collapse
|
20
|
Jaenike J, Stahlhut JK, Boelio LM, Unckless RL. Association between Wolbachia and Spiroplasma within Drosophila neotestacea: an emerging symbiotic mutualism? Mol Ecol 2009; 19:414-25. [PMID: 20002580 DOI: 10.1111/j.1365-294x.2009.04448.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interspecific mutualism can evolve when specific lineages of different species tend to be associated with each other from one generation to the next. Different maternally transmitted endosymbionts occurring within the same cytoplasmic lineage fulfil this requirement. Drosophila neotestacea is infected with maternally transmitted Wolbachia and Spiroplasma, which are cotransmitted at high frequency in natural populations. Molecular phylogenetic evidence indicates that both endosymbionts have been present in D. neotestacea for considerable evolutionary periods. Thus, conditions are suitable for the evolution of mutualism between them. In support of this possibility, there is a significant positive association between Wolbachia and Spiroplasma infection in many samples of D. neotestacea from natural populations. Theoretically, such a positive association can result from either mutualism between these endosymbionts or recent spread. Collections from present-day populations suggest that recent spread and mutualism have both operated to generate the positive association between Wolbachia and Spiroplasma. If selection acts on the combination of these two endosymbionts, they may be in the early stages of evolution of a more complex, cooperative association.
Collapse
Affiliation(s)
- John Jaenike
- Department of Biology, University of Rochester, Rochester, NY 14627, USA.
| | | | | | | |
Collapse
|
21
|
Ferree PM, Avery A, Azpurua J, Wilkes T, Werren JH. A bacterium targets maternally inherited centrosomes to kill males in Nasonia. Curr Biol 2008; 18:1409-14. [PMID: 18804376 DOI: 10.1016/j.cub.2008.07.093] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 07/28/2008] [Accepted: 07/30/2008] [Indexed: 10/21/2022]
Abstract
Male killing is caused by diverse microbial taxa in a wide range of arthropods. This phenomenon poses important challenges to understanding the dynamics of sex ratios and host-pathogen interactions. However, the mechanisms of male killing are largely unknown. Evidence from one case in Drosophila suggests that bacteria can target components of the male-specific sex-determination pathway. Here, we investigated male killing by the bacterium Arsenophonus nasoniae in the haplo-diploid wasp Nasonia vitripennis, in which females develop as diploids from fertilized eggs and males develop parthenogenetically as haploids from unfertilized eggs. We found that Arsenophonus inhibits the formation of maternal centrosomes, organelles required specifically for early male embryonic development, resulting in unorganized mitotic spindles and developmental arrest well before the establishment of somatic sexual identity. Consistent with these results, rescue of Arsenophonus-induced male lethality was achieved by fertilization with sperm bearing the supernumerary chromosome paternal sex ratio (PSR), which destroys the paternal genome but bypasses the need for maternal centrosomes by allowing transmission of the sperm-derived centrosome into the egg. These findings reveal a novel mechanism of male killing in Nasonia, demonstrating that bacteria have evolved different mechanisms for inducing male killing in the Arthropods.
Collapse
Affiliation(s)
- Patrick M Ferree
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
| | | | | | | | | |
Collapse
|
22
|
Sakamoto H, Kageyama D, Hoshizaki S, Ishikawa Y. Sex-specific death in the Asian corn borer moth (Ostrinia furnacalis) infected with Wolbachia occurs across larval development. Genome 2007; 50:645-52. [PMID: 17893742 DOI: 10.1139/g07-041] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Maternally inherited endosymbiotic bacteria of the genus Wolbachia induce various kinds of reproductive alterations in their arthropod hosts. In a Wolbachia-infected strain of the adzuki bean borer moth, Ostrinia scapulalis (Lepidoptera: Crambidae), males selectively die during larval development, while females selectively die when Wolbachia are eliminated by antibiotic treatment. We found that naturally occurring Wolbachia in the congener O. furnacalis caused sex-specific lethality similar to that in O. scapulalis. Cytogenetic analyses throughout the entire larval development clarified that the death of males (when infected) and females (when cured) took place mainly during early larval stages. However, some individuals also died after complete formation of larval bodies but before egg hatching, or at late larval stages, even in the penultimate instar. Although the specific timing was highly variable, death of males and females occurred before pupation without exception. The potential association of sex-specific lethality with the sex determination mechanism was also examined and is discussed.
Collapse
Affiliation(s)
- Hironori Sakamoto
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
| | | | | | | |
Collapse
|
23
|
Abstract
Fruit fly immunology is on the verge of an exciting new path. The fruit fly has served as a strong model for innate immune responses; the field is now expanding to use the fruit fly to study pathogenesis. We argue here that, to understand pathogenesis in the fly, we need to understand pathology - and to understand pathology, we need to confront physiology with molecular tools. When flies are infected with a pathogen, they get sick. We group the events following infection into three categories: innate immune responses (defence mechanisms by which the fly attempts to kill or neutralize the microbe, some of which can themselves cause harm to the fly); microbial virulence (mechanisms by which the microbe evades the immune response); and host pathology (physiologies adversely affected by either the immune response or microbial virulence). We divide this review into sections mirroring these categories. The molecular study of infection in the fruit fly has focused on the first category, has begun to explore the second, and has yet to tap the full potential of the fly regarding the third.
Collapse
Affiliation(s)
- Mimi M Shirasu-Hiza
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | | |
Collapse
|