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Affiliation(s)
- J.P. Bogart
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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Charney ND, Kubel JE, Woodard CT, Carbajal-González BI, Avis S, Blyth JA, Eiseman CS, Castorino J, Malone JH. Survival of Polyploid hybrid salamander embryos. BMC DEVELOPMENTAL BIOLOGY 2019; 19:21. [PMID: 31718554 PMCID: PMC6849221 DOI: 10.1186/s12861-019-0202-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 10/22/2019] [Indexed: 11/10/2022]
Abstract
Background Animals with polyploid, hybrid nuclei offer a challenge for models of gene expression and regulation during embryogenesis. To understand how such organisms proceed through development, we examined the timing and prevalence of mortality among embryos of unisexual salamanders in the genus Ambystoma. Results Our regional field surveys suggested that heightened rates of embryo mortality among unisexual salamanders begin in the earliest stages of embryogenesis. Although we expected elevated mortality after zygotic genome activation in the blastula stage, this is not what we found among embryos which we reared in the laboratory. Once embryos entered the first cleavage stage, we found no difference in mortality rates between unisexual salamanders and their bisexual hosts. Our results are consistent with previous studies showing high rates of unisexual mortality, but counter to reports that heightened embryo mortality continues throughout embryo development. Conclusions Possible causes of embryonic mortality in early embryogenesis suggested by our results include abnormal maternal loading of RNA during meiosis and barriers to insemination. The surprising survival rates of embryos post-cleavage invites further study of how genes are regulated during development in such polyploid hybrid organisms.
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Affiliation(s)
| | - Jacob E Kubel
- Natural Heritage & Endangered Species Program, Massachusetts Division of Fisheries and Wildlife, Westborough, MA, USA
| | | | | | | | | | | | | | - John H Malone
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, USA
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Bogart JP. A family study to examine clonal diversity in unisexual salamanders (genus Ambystoma). Genome 2019; 62:549-561. [DOI: 10.1139/gen-2019-0034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Unisexual Ambystoma are the oldest known unisexual vertebrates and comprise a lineage of eastern North American all female salamanders that reproduce by stealing sperm from as many as five normally bisexual congeneric species. The sperm may be used to only stimulate egg development by gynogenesis but can be incorporated in the zygote to elevate the ploidy level or to replace one of the female’s haploid genomes. This flexible and unique reproductive system, termed kleptogenesis, is investigated using a microsatellite examination of 988 offspring from 14 unisexual mothers. All mothers produced clonal and ploidy-elevated offspring. Genome replacement and multiple paternity are confirmed for the first time in unisexual Ambystoma. Microsatellite mutations were found in all five microsatellite loci and the estimated microsatellite mutation rate varied by locus and by genome. Clonal variation is attributed to the inclusion of sperm donors’ haploid genomes for ploidy elevation, genome replacement, mutations, and natural selection.
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Affiliation(s)
- James P. Bogart
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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Quilodrán CS, Currat M, Montoya-Burgos JI. Effect of hybridization with genome exclusion on extinction risk. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2018; 32:1139-1149. [PMID: 29691912 DOI: 10.1111/cobi.13120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 03/03/2018] [Indexed: 06/08/2023]
Abstract
Human-induced habitat changes may lead to the breakdown of reproductive barriers between distantly related species. This phenomenon may result in fertile first-generation hybrids (F1 ) that exclude the genome of one parental species during gametogenesis, thus disabling introgression. The species extinction risk associated with hybridization with genome exclusion is largely underappreciated because the phenomenon produces only F1 hybrid phenotype, leading to the misconception that hybrids are sterile and potentially of minor conservation concern. We used a simulation model that integrates the main genetic, demographic, and ecological processes to examine the dynamics of hybridization with genome exclusion. We showed that this mode of hybridization may lead to extremely rapid extinction when the process of genome exclusion is unbalanced between the interbreeding species and when the hybridization rate is not negligible. The coexistence of parental species was possible in some cases of asymmetrical genome exclusion, but show this equilibrium was highly vulnerable to environmental variation. Expanding the exclusive habitat of the species at risk allowed its persistence. Our results highlight the extent of possible extinction risk due to hybridization with genome exclusion and suggest habitat management as a promising conservation strategy. In anticipation of serious threats to biodiversity due to hybridization with genome exclusion, we recommend a detailed assessment of the reproductive status of hybrids in conservation programs. We suggest such assessments include the inspection of genetic content in hybrid gametes.
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Affiliation(s)
- Claudio S Quilodrán
- Laboratory of Anthropology, Genetics and Peopling History, Anthropology Unit, Department of Genetics and Evolution, University of Geneva, 1205 Geneva, Switzerland
- Laboratory of Vertebrate Evolution, Department of Genetics and Evolution, University of Geneva, 1205 Geneva, Switzerland
- Department of Zoology, University of Oxford, OX1 3PS, U.K
| | - Mathias Currat
- Laboratory of Anthropology, Genetics and Peopling History, Anthropology Unit, Department of Genetics and Evolution, University of Geneva, 1205 Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (IGE3), 1211 Geneva, Switzerland
| | - Juan I Montoya-Burgos
- Laboratory of Vertebrate Evolution, Department of Genetics and Evolution, University of Geneva, 1205 Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (IGE3), 1211 Geneva, Switzerland
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6
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Denton RD, Morales AE, Gibbs HL. Genome-specific histories of divergence and introgression between an allopolyploid unisexual salamander lineage and two ancestral sexual species. Evolution 2018; 72:1689-1700. [PMID: 29926914 DOI: 10.1111/evo.13528] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/07/2018] [Accepted: 06/14/2018] [Indexed: 02/06/2023]
Abstract
Quantifying introgression between sexual species and polyploid lineages traditionally thought to be asexual is an important step in understanding what drives the longevity of putatively asexual groups. Here, we capitalize on three recent innovations-ultraconserved element (UCE) sequencing, bioinformatic techniques for identifying genome-specific variation in polyploids, and model-based methods for evaluating historical gene flow-to measure the extent and tempo of introgression over the evolutionary history of an allopolyploid lineage of all-female salamanders and two ancestral sexual species. Our analyses support a scenario in which the genomes sampled in unisexual salamanders last shared a common ancestor with genomes in their parental species ∼3.4 million years ago, followed by a period of divergence between homologous genomes. Recently, secondary introgression has occurred at different times with each sexual species during the last 500,000 years. Sustained introgression of sexual genomes into the unisexual lineage is the defining characteristic of their reproductive mode, but this study provides the first evidence that unisexual genomes have undergone long periods of divergence without introgression. Unlike other sperm-dependent taxa in which introgression is rare, the alternating periods of divergence and introgression between unisexual salamanders and their sexual relatives could explain why these salamanders are among the oldest described unisexual animals.
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Affiliation(s)
- Robert D Denton
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio 43210
- Ohio Biodiversity Conservation Partnership, Columbus, Ohio 43210
- Current Address: Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
| | - Ariadna E Morales
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio 43210
| | - H Lisle Gibbs
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio 43210
- Ohio Biodiversity Conservation Partnership, Columbus, Ohio 43210
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7
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Beauregard F, Angers B. Influence of genome and bio-ecology on the prevalence of genome exchange in unisexuals of the Ambystoma complex. BMC Evol Biol 2018; 18:82. [PMID: 29855267 PMCID: PMC5984407 DOI: 10.1186/s12862-018-1200-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 05/21/2018] [Indexed: 11/15/2022] Open
Abstract
Background Unisexuals of the blue-spotted salamander complex are thought to reproduce by kleptogenesis. Genome exchanges associated with this sperm-dependent mode of reproduction are expected to result in a higher genetic variation and multiple ploidy levels compared to clonality. However, the existence of some populations exclusively formed of genetically identical individuals suggests that factors could prevent genome exchanges. This study aimed at assessing the prevalence of genome exchange among unisexuals of the Ambystoma laterale-jeffersonianum complex from 10 sites in the northern part of their distribution. Results A total of 235 individuals, including 207 unisexuals, were genotyped using microsatellite loci and AFLP. Unisexual individuals could be sorted in five genetically distinct groups, likely derived from the same paternal A. jeffersonianum haplome. One of these groups exclusively reproduced clonally, even when found in sympatry with lineages presenting signature of genome exchange. Genome exchange was site-dependent for another group. Genome exchange was detected at all sites for the three remaining groups. Conclusion Prevalence of genome exchange appears to be associated with ecological conditions such as availability of effective sperm donors. Intrinsic genomic factors may also affect this process, since different lineages in sympatry present highly variable rate of genome exchange. The coexistence of clonal and genetically diversified lineages opens the door to further research on alternatives to genetic variation. Electronic supplementary material The online version of this article (10.1186/s12862-018-1200-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- France Beauregard
- Departement of biological sciences, Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, QC, H3C 317, Canada
| | - Bernard Angers
- Departement of biological sciences, Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, QC, H3C 317, Canada.
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Doležálková-Kaštánková M, Pruvost NBM, Plötner J, Reyer HU, Janko K, Choleva L. All-male hybrids of a tetrapod Pelophylax esculentus share its origin and genetics of maintenance. Biol Sex Differ 2018; 9:13. [PMID: 29609661 PMCID: PMC5880063 DOI: 10.1186/s13293-018-0172-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 03/15/2018] [Indexed: 02/07/2023] Open
Abstract
Background Sexual parasites offer unique insights into the reproduction of unisexual and sexual populations. Because unisexuality is almost exclusively linked to the female sex, most studies addressed host-parasite dynamics in populations where sperm-dependent females dominate. Pelophylax water frogs from Central Europe include hybrids of both sexes, collectively named P. esculentus. They live syntopically with their parental species P. lessonae and/or P. ridibundus. Some hybrid lineages consist of all males providing a chance to understand the origin and perpetuation of a host-parasite (egg-dependent) system compared to sperm-dependent parthenogenesis. Methods We focused on P. ridibundus-P. esculentus populations where P. ridibundus of both sexes lives together with only diploid P. esculentus males. Based on 17 microsatellite markers and six allozyme loci, we analyzed (i) the variability of individual genomes, (ii) the reproductive mode(s) of all-male hybrids, and (iii) the genealogical relationships between the hybrid and parental genomes. Results Our microsatellite data revealed that P. esculentus males bear Mendelian-inherited ridibundus genomes while the lessonae genome represents a single clone. Our data indicate that this clone did not recently originate from adjacent P. lessonae populations, suggesting an older in situ or ex situ origin. Conclusions Our results confirm that also males can perpetuate over many generations as the unisexual lineage and successfully compete with P. ridibundus males for eggs provided by P. ridibundus females. Natural persistence of such sex-specific hybrid populations allows to studying the similarities and differences between male and female reproductive parasitism in many biological settings. Electronic supplementary material The online version of this article (10.1186/s13293-018-0172-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marie Doležálková-Kaštánková
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, 277 21, Liběchov, Czech Republic. .,Department of Zoology, Faculty of Science, Charles University in Prague, 128 43, Praha 2, Czech Republic.
| | - Nicolas B M Pruvost
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Jörg Plötner
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115, Berlin, Germany
| | - Heinz-Ulrich Reyer
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Karel Janko
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, 277 21, Liběchov, Czech Republic.,Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
| | - Lukáš Choleva
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, 277 21, Liběchov, Czech Republic. .,Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic.
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9
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McElroy KE, Denton RD, Sharbrough J, Bankers L, Neiman M, Gibbs HL. Genome Expression Balance in a Triploid Trihybrid Vertebrate. Genome Biol Evol 2017; 9:968-980. [PMID: 28369297 PMCID: PMC5396480 DOI: 10.1093/gbe/evx059] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2017] [Indexed: 01/17/2023] Open
Abstract
Polyploidy is increasingly recognized as a driver of biological diversity. How and why polyploidization affects gene expression is critical to understanding the link between ploidy elevation and diversification. In polyploid plants, multiple studies have demonstrated that ploidy elevation can confer major but variable consequences for gene expression, ranging from gene-by-gene alterations to entirely silenced genomes. By contrast, animal polyploids remain largely uncharacterized. Accordingly, how animals respond to and manage polyploidy events is not understood. Here, we address this important knowledge gap by analyzing transcriptomes from a triploid hybrid animal, a unisexual Ambystoma salamander, and three sexual Ambystoma species that represent all three parental genomes in the unisexual. We used a novel bioinformatics pipeline that includes competitively mapping triploid sequences to a reference set of orthologous genes in the sexual species to evaluate subgenome expression. Our comparisons of gene expression levels across the three parental genomes revealed that the unisexual triploid displays a pattern of genome balance, where 72% of the genes analyzed were expressed equally among the subgenomes. This result is strikingly different from the genome imbalance typically observed in hybrid polyploid plants. Our analyses represent the first to address gene expression in a triploid hybrid animal and introduce a novel bioinformatic framework for analyzing transcriptomic data.
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Affiliation(s)
- Kyle E McElroy
- Department of Biology, University of Iowa, Iowa City, IA
| | - Robert D Denton
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH.,Ohio Biodiversity Conservation Partnership, Ohio State University, Columbus, OH
| | - Joel Sharbrough
- Department of Biology, University of Iowa, Iowa City, IA.,Department of Biology, Colorado State University, Fort Collins, CO
| | - Laura Bankers
- Department of Biology, University of Iowa, Iowa City, IA
| | - Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, IA
| | - H Lisle Gibbs
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH.,Ohio Biodiversity Conservation Partnership, Ohio State University, Columbus, OH
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Denton RD, Greenwald KR, Gibbs HL. Locomotor endurance predicts differences in realized dispersal between sympatric sexual and unisexual salamanders. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12813] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Robert D. Denton
- Department of Evolution, Ecology and Organismal Biology Ohio State University, 300 Aronoff Laboratory, 318 West 12th Avenue Columbus OH 43210 USA
- Ohio Biodiversity Conservation Partnership Ohio State University, 300 Aronoff Laboratory, 318 West 12th Avenue Columbus OH 43210 USA
| | - Katherine R. Greenwald
- Department of Biology Eastern Michigan University, 441 Mark Jefferson Science Complex Ypsilanti MI 48197 USA
| | - H. Lisle Gibbs
- Department of Evolution, Ecology and Organismal Biology Ohio State University, 300 Aronoff Laboratory, 318 West 12th Avenue Columbus OH 43210 USA
- Ohio Biodiversity Conservation Partnership Ohio State University, 300 Aronoff Laboratory, 318 West 12th Avenue Columbus OH 43210 USA
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11
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Gibbs HL, Denton RD. Cryptic sex? Estimates of genome exchange in unisexual mole salamanders (Ambystomasp.). Mol Ecol 2016; 25:2805-15. [DOI: 10.1111/mec.13662] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 04/03/2016] [Accepted: 04/14/2016] [Indexed: 11/26/2022]
Affiliation(s)
- H. Lisle Gibbs
- Department of Evolution, Ecology and Organismal Biology and Ohio Biodiversity Conservation Partnership; Ohio State University; 318 W. 12th Avenue Columbus OH 43210 USA
| | - Robert D. Denton
- Department of Evolution, Ecology and Organismal Biology and Ohio Biodiversity Conservation Partnership; Ohio State University; 318 W. 12th Avenue Columbus OH 43210 USA
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12
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Saikkonen K, Young CA, Helander M, Schardl CL. Endophytic Epichloë species and their grass hosts: from evolution to applications. PLANT MOLECULAR BIOLOGY 2016; 90:665-75. [PMID: 26542393 PMCID: PMC4819788 DOI: 10.1007/s11103-015-0399-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/26/2015] [Indexed: 05/21/2023]
Abstract
The closely linked fitness of the Epichloë symbiont and the host grass is presumed to align the coevolution of the species towards specialization and mutually beneficial cooperation. Ecological observations demonstrating that Epichloë-grass symbioses can modulate grassland ecosystems via both above- and belowground ecosystem processes support this. In many cases the detected ecological importance of Epichloë species is directly or indirectly linked to defensive mutualism attributable to alkaloids of fungal-origin. Now, modern genetic and molecular techniques enable the precise studies on evolutionary origin of endophytic Epichloë species, their coevolution with host grasses and identification the genetic variation that explains phenotypic diversity in ecologically relevant characteristics of Epichloë-grass associations. Here we briefly review the most recent findings in these areas of research using the present knowledge of the genetic variation that explains the biosynthetic pathways driving the diversity of alkaloids produced by the endophyte. These findings underscore the importance of genetic interplay between the fungus and the host in shaping their coevolution and ecological role in both natural grass ecosystems, and in the agricultural arena.
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Affiliation(s)
- Kari Saikkonen
- Management and Production of Renewable Resources, Natural Resources Institute Finland (Luke), Itäinen Pitkäkatu 3, 20520, Turku, Finland.
| | - Carolyn A Young
- The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA
| | - Marjo Helander
- Management and Production of Renewable Resources, Natural Resources Institute Finland (Luke), Itäinen Pitkäkatu 3, 20520, Turku, Finland
- Section of Ecology, Department of Biology, University of Turku, 20014, Turku, Finland
| | - Christopher L Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, KY, 40546-0312, USA
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14
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Charney ND, Castorino JJ, Dobro MJ, Steely SL. Embryo development inside female salamander (Ambystoma jeffersonianum-laterale) prior to egg laying. PLoS One 2014; 9:e91919. [PMID: 24651275 PMCID: PMC3961271 DOI: 10.1371/journal.pone.0091919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 02/18/2014] [Indexed: 11/19/2022] Open
Abstract
The length of embryo retention prior to oviposition is a critical evolutionary trait. In all oviparous salamanders, which include the vast majority of species in the order, fertilization is thought to occur at the time of egg laying. Embryos then enter the first cleavage stage several hours after being deposited. This pattern holds for previously studied individuals in the Ambystoma jeffersonianum-laterale complex. Here, we document an instance in which a female Ambystoma jeffersonianum-laterale was carrying embryos internally that had already reached stage 10 of development. Development likely began several days prior to the start of migration to the breeding pond. This is the first such record for any egg-laying salamander, and suggests a degree of plasticity in the timing of fertilization and development not previously recognized. Further work is needed to ascertain the prevalence, mechanics, and evolutionary significance of this phenomenon.
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Affiliation(s)
- Noah D. Charney
- School of Natural Science, Hampshire College, Amherst, Massachusetts, United States of America
| | - John J. Castorino
- School of Natural Science, Hampshire College, Amherst, Massachusetts, United States of America
| | - Megan J. Dobro
- School of Natural Science, Hampshire College, Amherst, Massachusetts, United States of America
| | - Sarah L. Steely
- School of Natural Science, Hampshire College, Amherst, Massachusetts, United States of America
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Bogart JP, Bi K. Genetic and genomic interactions of animals with different ploidy levels. Cytogenet Genome Res 2013; 140:117-36. [PMID: 23751376 DOI: 10.1159/000351593] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Polyploid animals have independently evolved from diploids in diverse taxa across the tree of life. We review a few polyploid animal species or biotypes where recently developed molecular and cytogenetic methods have significantly improved our understanding of their genetics, reproduction and evolution. Mitochondrial sequences that target the maternal ancestor of a polyploid show that polyploids may have single (e.g. unisexual salamanders in the genus Ambystoma) or multiple (e.g. parthenogenetic polyploid lizards in the genus Aspidoscelis) origins. Microsatellites are nuclear markers that can be used to analyze genetic recombinations, reproductive modes (e.g. Ambystoma) and recombination events (e.g. polyploid frogs such as Pelophylax esculentus). Hom(e)ologous chromosomes and rare intergenomic exchanges in allopolyploids have been distinguished by applying genome-specific fluorescent probes to chromosome spreads. Polyploids arise, and are maintained, through perturbations of the 'normal' meiotic program that would include pre-meiotic chromosome replication and genomic integrity of homologs. When possible, asexual, unisexual and bisexual polyploid species or biotypes interact with diploid relatives, and genes are passed from diploid to polyploid gene pools, which increase genetic diversity and ultimately evolutionary flexibility in the polyploid. When diploid relatives do not exist, polyploids can interact with another polyploid (e.g. species of African Clawed Frogs in the genus Xenopus). Some polyploid fish (e.g. salmonids) and frogs (Xenopus) represent independent lineages whose ancestors experienced whole genome duplication events. Some tetraploid frogs (P. esculentus) and fish (Squaliusalburnoides) may be in the process of becoming independent species, but diploid and triploid forms of these 'species' continue to genetically interact with the comparatively few tetraploid populations. Genetic and genomic interaction between polyploids and diploids is a complex and dynamic process that likely plays a crucial role for the evolution and persistence of polyploid animals. See also other articles in this themed issue.
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Affiliation(s)
- J P Bogart
- Department of Integrative Biology, University of Guelph, Guelph, Ont., Canada. jbogart @ uoguelph.ca
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16
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Evolutionary and ecological implications of sexual parasitism. Trends Ecol Evol 2013; 28:297-306. [DOI: 10.1016/j.tree.2012.12.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 12/14/2012] [Accepted: 12/30/2012] [Indexed: 11/21/2022]
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17
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Choleva L, Janko K. Rise and Persistence of Animal Polyploidy: Evolutionary Constraints and Potential. Cytogenet Genome Res 2013; 140:151-70. [DOI: 10.1159/000353464] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Morris MR, Goedert D, Abbott JK, Robinson DM, Rios-Cardenas O. Intralocus Tactical Conflict and the Evolution of Alternative Reproductive Tactics. ADVANCES IN THE STUDY OF BEHAVIOR 2013. [DOI: 10.1016/b978-0-12-407186-5.00007-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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