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Stångberg J, Immonen E, Moreno PP, Bolund E. Experimentally induced intrasexual mating competition and sex-specific evolution in female and male nematodes. J Evol Biol 2020; 33:1677-1688. [PMID: 32945028 PMCID: PMC7756511 DOI: 10.1111/jeb.13706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/28/2020] [Accepted: 09/04/2020] [Indexed: 01/01/2023]
Abstract
Sexual dimorphism in life history traits and their trade-offs is widespread among sexually reproducing animals and is strongly influenced by the differences in reproductive strategies between the sexes. We investigated how intrasexual competition influenced specific life history traits, important to fitness and their trade-offs in the outcrossing nematode Caenorhabditis remanei. Here, we altered the strength of sex-specific selection through experimental evolution with increased potential for intrasexual competition by skewing the adult sex ratio towards either females or males (1:10 or 10:1) over 30 generations and subsequently measured the phenotypic response to selection in three traits related to fitness: body size, fecundity and tolerance to heat stress. We observed a greater evolutionary change in females than males for body size and peak fitness, suggesting that females may experience stronger net selection and potentially harbour higher amounts of standing genetic variance compared to males. Our study highlights the importance of investigating direct and indirect effects of intrasexual competition in both sexes in order to capture sex-specific responses and understand the evolution of sexual dimorphism in traits expressed by both sexes.
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Affiliation(s)
- Josefine Stångberg
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Elina Immonen
- Department of Ecology and Genetics, Evolutionary Biology, Uppsala University, Uppsala, Sweden
| | - Pilar Puimedon Moreno
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Elisabeth Bolund
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
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2
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Cutter AD, Morran LT, Phillips PC. Males, Outcrossing, and Sexual Selection in Caenorhabditis Nematodes. Genetics 2019; 213:27-57. [PMID: 31488593 PMCID: PMC6727802 DOI: 10.1534/genetics.119.300244] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 06/06/2019] [Indexed: 12/15/2022] Open
Abstract
Males of Caenorhabditis elegans provide a crucial practical tool in the laboratory, but, as the rarer and more finicky sex, have not enjoyed the same depth of research attention as hermaphrodites. Males, however, have attracted the attention of evolutionary biologists who are exploiting the C. elegans system to test longstanding hypotheses about sexual selection, sexual conflict, transitions in reproductive mode, and genome evolution, as well as to make new discoveries about Caenorhabditis organismal biology. Here, we review the evolutionary concepts and data informed by study of males of C. elegans and other Caenorhabditis We give special attention to the important role of sperm cells as a mediator of inter-male competition and male-female conflict that has led to drastic trait divergence across species, despite exceptional phenotypic conservation in many other morphological features. We discuss the evolutionary forces important in the origins of reproductive mode transitions from males being common (gonochorism: females and males) to rare (androdioecy: hermaphrodites and males) and the factors that modulate male frequency in extant androdioecious populations, including the potential influence of selective interference, host-pathogen coevolution, and mutation accumulation. Further, we summarize the consequences of males being common vs rare for adaptation and for trait divergence, trait degradation, and trait dimorphism between the sexes, as well as for molecular evolution of the genome, at both micro-evolutionary and macro-evolutionary timescales. We conclude that C. elegans male biology remains underexploited and that future studies leveraging its extensive experimental resources are poised to discover novel biology and to inform profound questions about animal function and evolution.
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Affiliation(s)
- Asher D Cutter
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario M5S3B2, Canada
| | - Levi T Morran
- Department of Biology, Emory University, Atlanta, Georgia 30322, and
| | - Patrick C Phillips
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon 97403
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3
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Woodruff GC, Johnson E, Phillips PC. A large close relative of C. elegans is slow-developing but not long-lived. BMC Evol Biol 2019; 19:74. [PMID: 30866802 PMCID: PMC6416856 DOI: 10.1186/s12862-019-1388-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 02/13/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Variation in body size is thought to be a major driver of a wide variety of ecological and evolutionary patterns, including changes in development, reproduction, and longevity. Additionally, drastic changes in natural context often have profound effects on multiple fitness-related traits. Caenorhabditis inopinata is a recently-discovered fig-associated nematode that is unusually large relative to other members of the genus, including the closely related model system C. elegans. Here we test whether the dramatic increase in body size and shift in ecological context has led to correlated changes in key life history and developmental parameters within this species. RESULTS Using four developmental milestones, C. inopinata was found to have a slower rate of development than C. elegans across a range of temperatures. Despite this, C. inopinata did not reveal any differences in adult lifespan from C. elegans after accounting for differences in developmental timing and reproductive mode. C. inopinata fecundity was generally lower than that of C. elegans, but fitness improved under continuous-mating, consistent with sperm-limitation under gonochoristic (male/female) reproduction. C. inopinata also revealed greater fecundity and viability at higher temperatures. CONCLUSION Consistent with observations in other ectotherms, slower growth in C. inopinata indicates a potential trade-off between body size and developmental timing, whereas its unchanged lifespan suggests that longevity is largely uncoupled from its increase in body size. Additionally, temperature-dependent patterns of fitness in C. inopinata are consistent with its geographic origins in subtropical Okinawa. Overall, these results underscore the extent to which changes in ecological context and body size can shape life history traits.
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Affiliation(s)
- Gavin C. Woodruff
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, USA
| | - Erik Johnson
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, USA
| | - Patrick C. Phillips
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, USA
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4
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Hare RM, Simmons LW. Sexual selection and its evolutionary consequences in female animals. Biol Rev Camb Philos Soc 2018; 94:929-956. [DOI: 10.1111/brv.12484] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/31/2018] [Accepted: 11/02/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Robin M. Hare
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia 35 Stirling Highway, Perth, 6009 Australia
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia 35 Stirling Highway, Perth, 6009 Australia
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5
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Ting JJ, Cutter AD. Demographic consequences of reproductive interference in multi-species communities. BMC Ecol 2018; 18:46. [PMID: 30400870 PMCID: PMC6219154 DOI: 10.1186/s12898-018-0201-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 10/26/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Reproductive interference can mediate interference competition between species through sexual interactions that reduce the fitness of one species by another. Theory shows that the positive frequency-dependent effects of such costly errors in mate recognition can dictate species coexistence or exclusion even with countervailing resource competition differences between species. While usually framed in terms of pre-mating or post-zygotic costs, reproductive interference manifests between individual Caenorhabditis nematodes from negative interspecies gametic interactions: sperm cells from interspecies matings can migrate ectopically to induce female sterility and premature death. The potential for reproductive interference to exert population level effects on Caenorhabditis trait evolution and community structure, however, remains unknown. RESULTS Here we test whether a species that is superior in individual-level reproductive interference (C. nigoni) can exact negative demographic effects on competitor species that are superior in resource competition (C. briggsae and C. elegans). We observe coexistence over six generations and find evidence of demographic reproductive interference even under conditions unfavorable to its influence. C. briggsae and C. elegans show distinct patterns of reproductive interference in competitive interactions with C. nigoni. CONCLUSIONS These results affirm that individual level negative effects of reproductive interference mediated by gamete interactions can ramify to population demography, with the potential to influence patterns of species coexistence separately from the effects of direct resource competition.
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Affiliation(s)
- Janice J Ting
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, M5S3B2, Canada
| | - Asher D Cutter
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, M5S3B2, Canada.
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Yang S, Gao X, Meng J, Zhang A, Zhou Y, Long M, Li B, Deng W, Jin L, Zhao S, Wu D, He Y, Li C, Liu S, Huang Y, Zhang H, Zou L. Metagenomic Analysis of Bacteria, Fungi, Bacteriophages, and Helminths in the Gut of Giant Pandas. Front Microbiol 2018; 9:1717. [PMID: 30108570 PMCID: PMC6080571 DOI: 10.3389/fmicb.2018.01717] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 07/10/2018] [Indexed: 11/13/2022] Open
Abstract
To obtain full details of gut microbiota, including bacteria, fungi, bacteriophages, and helminths, in giant pandas (GPs), we created a comprehensive microbial genome database and used metagenomic sequences to align against the database. We delineated a detailed and different gut microbiota structures of GPs. A total of 680 species of bacteria, 198 fungi, 185 bacteriophages, and 45 helminths were found. Compared with 16S rRNA sequencing, the dominant bacterium phyla not only included Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria but also Cyanobacteria and other eight phyla. Aside from Ascomycota, Basidiomycota, and Glomeromycota, Mucoromycota, and Microsporidia were the dominant fungi phyla. The bacteriophages were predominantly dsDNA Myoviridae, Siphoviridae, Podoviridae, ssDNA Inoviridae, and Microviridae. For helminths, phylum Nematoda was the dominant. In addition to previously described parasites, another 44 species of helminths were found in GPs. Also, differences in abundance of microbiota were found between the captive, semiwild, and wild GPs. A total of 1,739 genes encoding cellulase, β-glucosidase, and cellulose β-1,4-cellobiosidase were responsible for the metabolism of cellulose, and 128,707 putative glycoside hydrolase genes were found in bacteria/fungi. Taken together, the results indicated not only bacteria but also fungi, bacteriophages, and helminths were diverse in gut of giant pandas, which provided basis for the further identification of role of gut microbiota. Besides, metagenomics revealed that the bacteria/fungi in gut of GPs harbor the ability of cellulose and hemicellulose degradation.
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Affiliation(s)
- Shengzhi Yang
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Xin Gao
- Department of Nutrition and Food Science, University of Maryland, College Park, College Park, MD, United States
| | - Jianghong Meng
- Department of Nutrition and Food Science, University of Maryland, College Park, College Park, MD, United States
| | - Anyun Zhang
- College of Life Sciences, Sichuan University, Chengdu, China
| | - Yingmin Zhou
- The China Conservation and Research Center for the Giant Panda, Wolong, China
| | - Mei Long
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Bei Li
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Wenwen Deng
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Lei Jin
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Siyue Zhao
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Daifu Wu
- The China Conservation and Research Center for the Giant Panda, Wolong, China
| | - Yongguo He
- The China Conservation and Research Center for the Giant Panda, Wolong, China
| | - Caiwu Li
- The China Conservation and Research Center for the Giant Panda, Wolong, China
| | - Shuliang Liu
- College of Food Science, Sichuan Agricultural University, Ya’an, China
| | - Yan Huang
- The China Conservation and Research Center for the Giant Panda, Wolong, China
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in The Giant Panda National Park (China Conservation and Research Center of Giant Panda), Wolong, China
| | - Hemin Zhang
- The China Conservation and Research Center for the Giant Panda, Wolong, China
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in The Giant Panda National Park (China Conservation and Research Center of Giant Panda), Wolong, China
| | - Likou Zou
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
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7
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Schütz D, Tschirren L, Pachler G, Grubbauer P, Taborsky M. Sperm-limited males save ejaculates for future matings when competing with superior rivals. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2016.12.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Duthie AB, Bocedi G, Reid JM. When does female multiple mating evolve to adjust inbreeding? Effects of inbreeding depression, direct costs, mating constraints, and polyandry as a threshold trait. Evolution 2016; 70:1927-43. [PMID: 27464756 PMCID: PMC5053304 DOI: 10.1111/evo.13005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 07/06/2016] [Indexed: 12/18/2022]
Abstract
Polyandry is often hypothesized to evolve to allow females to adjust the degree to which they inbreed. Multiple factors might affect such evolution, including inbreeding depression, direct costs, constraints on male availability, and the nature of polyandry as a threshold trait. Complex models are required to evaluate when evolution of polyandry to adjust inbreeding is predicted to arise. We used a genetically explicit individual‐based model to track the joint evolution of inbreeding strategy and polyandry defined as a polygenic threshold trait. Evolution of polyandry to avoid inbreeding only occurred given strong inbreeding depression, low direct costs, and severe restrictions on initial versus additional male availability. Evolution of polyandry to prefer inbreeding only occurred given zero inbreeding depression and direct costs, and given similarly severe restrictions on male availability. However, due to its threshold nature, phenotypic polyandry was frequently expressed even when strongly selected against and hence maladaptive. Further, the degree to which females adjusted inbreeding through polyandry was typically very small, and often reflected constraints on male availability rather than adaptive reproductive strategy. Evolution of polyandry solely to adjust inbreeding might consequently be highly restricted in nature, and such evolution cannot necessarily be directly inferred from observed magnitudes of inbreeding adjustment.
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Affiliation(s)
- A Bradley Duthie
- Institute of Biological and Environmental Sciences, School of Biological Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom.
| | - Greta Bocedi
- Institute of Biological and Environmental Sciences, School of Biological Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
| | - Jane M Reid
- Institute of Biological and Environmental Sciences, School of Biological Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
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9
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Leighton DH, Sternberg PW. Mating pheromones of Nematoda: olfactory signaling with physiological consequences. Curr Opin Neurobiol 2016; 38:119-24. [PMID: 27213246 DOI: 10.1016/j.conb.2016.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/11/2016] [Accepted: 04/12/2016] [Indexed: 01/17/2023]
Abstract
Secreted pheromones have long been known to influence mating in the phylum Nematoda. The study of nematode sexual behavior has greatly benefited in the last decade from the genetic and neurobiological tools available for the model nematode Caenorhabditis elegans, as well as from the chemical identification of many pheromones secreted by this species. The discovery that nematodes can influence one another's physiological development and stress responsiveness through the sharing of pheromones, in addition to simply triggering sexual attraction, is particularly striking. Here we review recent research on nematode mating pheromones, which has been conducted predominantly on C. elegans, but there are beginning to be parallel studies in other species.
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Affiliation(s)
- Daniel Hw Leighton
- HHMI and Division of Biology and Biological Engineering, Caltech, Pasadena 91125, USA
| | - Paul W Sternberg
- HHMI and Division of Biology and Biological Engineering, Caltech, Pasadena 91125, USA.
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10
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Ebel ER, Phillips PC. Intrinsic differences between males and females determine sex-specific consequences of inbreeding. BMC Evol Biol 2016; 16:36. [PMID: 26860745 PMCID: PMC4748534 DOI: 10.1186/s12862-016-0604-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/28/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Inbreeding increases homozygosity and exposes deleterious recessive alleles, generally decreasing the fitness of inbred individuals. Interestingly, males and females are usually affected differently by inbreeding, though the more vulnerable sex depends on the species and trait measured. RESULTS We used the soil-dwelling nematode Caenorhabditis remanei to examine sex-specific inbreeding depression across nine lineages, five levels of inbreeding, and hundreds of thousands of progeny. Female nematodes consistently suffered greater fitness losses than their male counterparts, especially at high levels of inbreeding. CONCLUSIONS These results suggest that females experience stronger selection on genes contributing to reproductive traits. Inbreeding depression in males may be further reduced by sex chromosome hemizygosity, which affects the dominance of some mutations, as well as by the absence of sexual selection. Determining the relative contributions of sex-specific expression, genes on the sex chromosomes, and the environment they are filtered through-including opportunities for sexual selection-may explain the frequent though inconsistent records of sex differences in inbreeding depression, along with their implications for conservation and the evolution of mating systems.
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Affiliation(s)
- Emily R Ebel
- Institute of Ecology and Evolution and Department of Biology, 5289 University of Oregon, 97403, Eugene, Oregon, USA.,Present address: Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA, 94305, USA
| | - Patrick C Phillips
- Institute of Ecology and Evolution and Department of Biology, 5289 University of Oregon, 97403, Eugene, Oregon, USA.
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11
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Fritzsche K, Timmermeyer N, Wolter M, Michiels NK. Female, but not male, nematodes evolve under experimental sexual coevolution. Proc Biol Sci 2015; 281:20140942. [PMID: 25339719 DOI: 10.1098/rspb.2014.0942] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Coevolution between the sexes is often considered to be male-driven: the male genome is constantly scanned by selection for traits that increase relative male fertilization success. Whenever these traits are harmful to females, the female genome is scanned for resistance traits. The resulting antagonistic coevolution between the sexes is analogous to Red Queen dynamics, where adaptation and counteradaptation keep each other in check. However, the underlying assumption that male trait evolution precedes female trait counteradaptation has received few empirical tests. Using the gonochoristic nematode Caenorhabditis remanei, we now show that 20 generations of relaxed versus increased sexual selection pressure lead to female, but not to male, trait evolution, questioning the generality of a male-driven process.
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Affiliation(s)
- K Fritzsche
- Department of Animal Evolutionary Ecology, Institute for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - N Timmermeyer
- Department of Animal Evolutionary Ecology, Institute for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - M Wolter
- Department of Animal Evolutionary Ecology, Institute for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - N K Michiels
- Department of Animal Evolutionary Ecology, Institute for Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
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12
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Abstract
Recent research has filled many gaps about Caenorhabditis natural history, simultaneously exposing how much remains to be discovered. This awareness now provides means of connecting ecological and evolutionary theory with diverse biological patterns within and among species in terms of adaptation, sexual selection, breeding systems, speciation, and other phenomena. Moreover, the heralded laboratory tractability of C. elegans, and Caenorhabditis species generally, provides a powerful case study for experimental hypothesis testing about evolutionary and ecological processes to levels of detail unparalleled by most study systems. Here, I synthesize pertinent theory with what we know and suspect about Caenorhabditis natural history for salient features of biodiversity, phenotypes, population dynamics, and interactions within and between species. I identify topics of pressing concern to advance Caenorhabditis biology and to study general evolutionary processes, including the key opportunities to tackle problems in dispersal dynamics, competition, and the dimensionality of niche space.
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Affiliation(s)
- Asher D Cutter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
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13
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Palopoli MF, Peden C, Woo C, Akiha K, Ary M, Cruze L, Anderson JL, Phillips PC. Natural and experimental evolution of sexual conflict within Caenorhabditis nematodes. BMC Evol Biol 2015; 15:93. [PMID: 25994934 PMCID: PMC4455605 DOI: 10.1186/s12862-015-0377-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/08/2015] [Indexed: 12/04/2022] Open
Abstract
Background Although males and females need one another in order to reproduce, they often have different reproductive interests, which can lead to conflict between the sexes. The intensity and frequency of male-male competition for fertilization opportunities is thought to be an important contributor to this conflict. The nematode genus Caenorhabditis provides an opportunity to test this hypothesis because the frequency of males varies widely among species with different mating systems. Results We find evidence that there is strong inter- and intra-sexual conflict within C. remanei, a dioecious species composed of equal frequencies of males and females. In particular, some C. remanei males greatly reduce female lifespan following mating, and their sperm have a strong competitive advantage over the sperm of other males. In contrast, our results suggest that both types of conflict have been greatly reduced within C. elegans, which is an androdioecious species that is composed of self-fertilizing hermaphrodites and rare males. Using experimental evolution in mutant C. elegans populations in which sperm production is blocked in hermaphrodites (effectively converting them to females), we find that the consequences of sexual conflict observed within C. remanei evolve rapidly within C. elegans populations experiencing high levels of male-male competition. Conclusions Together, these complementary data sets support the hypothesis that the intensity of intersexual conflict varies with the intensity of competition among males, and that male-induced collateral damage to mates can evolve very rapidly within populations.
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Affiliation(s)
| | - Colin Peden
- Institute of Ecology and Evolution, University of Oregon, OR 97403, Eugene, USA.
| | - Caitlin Woo
- Department of Biology, Bowdoin College, ME 04011, Brunswick, USA.
| | - Ken Akiha
- Department of Biology, Bowdoin College, ME 04011, Brunswick, USA.
| | - Megan Ary
- Institute of Ecology and Evolution, University of Oregon, OR 97403, Eugene, USA. .,Current address: South Lane School District, OR 97424, Cottage Grove, USA.
| | - Lori Cruze
- Institute of Ecology and Evolution, University of Oregon, OR 97403, Eugene, USA. .,Current address: Department of Obstetrics and Gynecology, Medical University of South Carolina, SC 29412, Charleston, USA.
| | - Jennifer L Anderson
- Institute of Ecology and Evolution, University of Oregon, OR 97403, Eugene, USA. .,Current address: INRA, UR1037 LPGP, Campus de Beaulieu, F-35000, Rennes, France.
| | - Patrick C Phillips
- Institute of Ecology and Evolution, University of Oregon, OR 97403, Eugene, USA.
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14
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Ting JJ, Woodruff GC, Leung G, Shin NR, Cutter AD, Haag ES. Intense sperm-mediated sexual conflict promotes reproductive isolation in Caenorhabditis nematodes. PLoS Biol 2014; 12:e1001915. [PMID: 25072732 PMCID: PMC4114750 DOI: 10.1371/journal.pbio.1001915] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 06/19/2014] [Indexed: 01/08/2023] Open
Abstract
Sperm from other species invade female tissues to cause sterility and death, helping to keep nematode species boundaries intact. Conflict between the sexes over reproductive interests can drive rapid evolution of reproductive traits and promote speciation. Here we show that inter-species mating between Caenorhabditis nematodes sterilizes maternal individuals. The principal effectors of male-induced harm are sperm cells, which induce sterility and shorten lifespan by displacing conspecific sperm, invading the ovary, and sometimes breaching the gonad to infiltrate other tissues. This sperm-mediated harm is pervasive across species, but idiosyncrasies in its magnitude implicate both independent histories of sexually antagonistic coevolution within species and differences in reproductive mode (self-fertilizing hermaphrodites versus females) in determining its severity. Consistent with this conclusion, in androdioecious species the hermaphrodites are more vulnerable, the males more benign, or both. Patterns of assortative mating and a low incidence of invasive sperm occurring with conspecific mating are indicative of ongoing intra-specific sexual conflict that results in inter-species reproductive incompatibility. The sexes have divergent reproductive interests, and conflict arising from this disparity can drive the rapid evolution of reproductive traits and promote speciation. Here we describe a unique reproductive barrier in Caenorhabditis nematodes that is induced by sperm. We found that mating between species can sterilize maternal worms and even cause premature death, and we were able to attribute this phenomenon directly to the sperm themselves. Sperm from other species can displace sperm from the same species and, in some cases, can invade inappropriate parts of the maternal reproductive system and even their non-reproductive tissues. We find that mating to males of another species harms females far more than does within-species mating. Overall, our observations are consistent with ongoing sexual conflict between the sexes within species, arising as a byproduct of sperm competition among the gametes of different males. Finally, patterns of assortative mating indicate that mating behaviours that reduce the likelihood of costly inter-species mating have evolved in this group of animals. These findings support an important role of sexual selection and gametic interactions contributing to reproductive boundaries between species, as predicted by evolutionary theory.
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Affiliation(s)
- Janice J. Ting
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Gavin C. Woodruff
- Department of Biology, University of Maryland, College Park, Maryland, United States of America
| | - Gemma Leung
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Na-Ra Shin
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Asher D. Cutter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- * E-mail: (ADC); (ESH)
| | - Eric S. Haag
- Department of Biology, University of Maryland, College Park, Maryland, United States of America
- * E-mail: (ADC); (ESH)
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15
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Abstract
Males and females have different evolutionary interests resulting in sexual conflict over optimal life histories. A new study in Caenorhabditis elegans shows that males hijack female physiology after mating to cause body shrinking and, ultimately, death. But how do males benefit from female demise?
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Affiliation(s)
- Martyna Zwoinska
- Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, SE-752 36, Sweden
| | - Martin I Lind
- Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, SE-752 36, Sweden
| | - Alexei A Maklakov
- Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, SE-752 36, Sweden.
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Determinants of female fecundity in a simultaneous hermaphrodite: the role of polyandry and food availability. Evol Ecol 2010. [DOI: 10.1007/s10682-010-9402-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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