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Darcy HE, Anderson PSL. Morphological variation in the vomer of aquatic and terrestrial spelerpini salamanders. J Morphol 2023; 284:e21618. [PMID: 37585223 DOI: 10.1002/jmor.21618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/28/2023] [Accepted: 07/01/2023] [Indexed: 08/17/2023]
Abstract
The vomer is an important tooth-bearing cranial bone in the lungless salamanders (Caudata: Plethodontidae) that serves different functional roles in aquatic versus terrestrial feeding. Vomerine tooth rows that run parallel with the maxillary teeth are thought to help grasp prey while expelling water from the mouth, while posterior extensions of the tooth row may help terrestrial taxa bring prey down the throat. We hypothesize that these two general morphological types will correlate with the habitat (aquatic vs. terrestrial) of adult salamanders. Alternatively, variation in form may be due to taxonomic effects, such that closely related species will have similar vomer morphology regardless of adult habitat. To test this hypothesis, we examined vomer shape on a set of species of the morphologically diverse tribe Spelerpini, in which two of the five genera (Eurycea and Gyrinophilus) include both aquatic and terrestrial species. Data were collected using micro computed tomography (micro-CT) scans from specimens from the Field Museum of Natural History and the Illinois Natural History Survey; additional data was obtained from public online repositories including Morphosource.org. Two-dimensional geometric morphometric analyses were performed to capture shape variation of both the vomer and the vomerine tooth row. We found clear separation between aquatic and terrestrial taxa, with most of the variation due to differences in the vomerine tooth row. Differences ascribed to habitat use likely correspond to feeding behavior, and the functional role of the vomer in prey processing warrants further investigation in this species-rich salamander family.
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Affiliation(s)
- Hannah E Darcy
- Department of Evolution, Ecology, and Behavior, University of Illinois Urbana-Champaign, Champaign, Illinois, USA
| | - Philip S L Anderson
- Department of Evolution, Ecology, and Behavior, University of Illinois Urbana-Champaign, Champaign, Illinois, USA
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2
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DeBruin JH, Wilburn DB, Feldhoff RC, Staub NL. Presence of sodefrin precursor-like factor pheromone candidates in mental and dorsal tail base glands in the plethodontid salamander, Karsenia koreana. PLoS One 2023; 18:e0289296. [PMID: 37527281 PMCID: PMC10393140 DOI: 10.1371/journal.pone.0289296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 07/16/2023] [Indexed: 08/03/2023] Open
Abstract
Plethodontid salamanders are well known for their distinct courtship rituals and the associated pheromonal signaling. However, little is known about pheromones produced in the lone Asian plethodontid species Karsenia koreana. Here, we examined the localization patterns of proteins of the sodefrin precursor-like factor (SPF) pheromone system in K. koreana. Using an antibody generated against SPF proteins from another plethodontid, Desmognathus ocoee, we tested three types of skin glands in K. koreana males via immunohistochemistry: the mental gland and two types of dorsal tail base glands-caudal courtship glands and dorsal granular glands. SPF immunoreactivity was detected in the known courtship gland, the mental gland, as well as granular glands, but not in caudal courtship glands. Due to immunoreaction specificity, we hypothesize the proteins of the SPF system in K. koreana and D. ocoee are structurally and functionally related and are used as courtship pheromones in K. koreana. Also, we hypothesize that K. koreana males transmit SPF to the female during the tail-straddling walk via dorsal granular glands. Finally, K. koreana male caudal courtship glands may be producing SPF proteins that are not recognized by our SPF antibody or these glands may play a different role in courtship than anticipated.
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Affiliation(s)
- Jared H DeBruin
- Department of Biology, Gonzaga University, Spokane, Washington, United States of America
| | - Damien B Wilburn
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Richard C Feldhoff
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Nancy L Staub
- Department of Biology, Gonzaga University, Spokane, Washington, United States of America
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3
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Fritzsch B, Schultze HP, Elliott KL. The evolution of the various structures required for hearing in Latimeria and tetrapods. IBRO Neurosci Rep 2023; 14:325-341. [PMID: 37006720 PMCID: PMC10063410 DOI: 10.1016/j.ibneur.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Sarcopterygians evolved around 415 Ma and have developed a unique set of features, including the basilar papilla and the cochlear aqueduct of the inner ear. We provide an overview that shows the morphological integration of the various parts needed for hearing, e.g., basilar papilla, tectorial membrane, cochlear aqueduct, lungs, and tympanic membranes. The lagena of the inner ear evolved from a common macula of the saccule several times. It is near this lagena where the basilar papilla forms in Latimeria and tetrapods. The basilar papilla is lost in lungfish, certain caecilians and salamanders, but is transformed into the cochlea of mammals. Hearing in bony fish and tetrapods involves particle motion to improve sound pressure reception within the ear but also works without air. Lungs evolved after the chondrichthyans diverged and are present in sarcopterygians and actinopterygians. Lungs open to the outside in tetraposomorph sarcopterygians but are transformed from a lung into a swim bladder in ray-finned fishes. Elasmobranchs, polypterids, and many fossil fishes have open spiracles. In Latimeria, most frogs, and all amniotes, a tympanic membrane covering the spiracle evolved independently. The tympanic membrane is displaced by pressure changes and enabled tetrapods to perceive airborne sound pressure waves. The hyomandibular bone is associated with the spiracle/tympanic membrane in actinopterygians and piscine sarcopterygians. In tetrapods, it transforms into the stapes that connects the oval window of the inner ear with the tympanic membrane and allows hearing at higher frequencies by providing an impedance matching and amplification mechanism. The three characters-basilar papilla, cochlear aqueduct, and tympanic membrane-are fluid related elements in sarcopterygians, which interact with a set of unique features in Latimeria. Finally, we explore the possible interaction between the unique intracranial joint, basicranial muscle, and an enlarged notochord that allows fluid flow to the foramen magnum and the cochlear aqueduct which houses a comparatively small brain.
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Affiliation(s)
- Bernd Fritzsch
- Department of Biology & Department of Otolaryngology, University of Iowa, IA, USA
- Correspondence to: Department of Biology & Department of Otolaryngology, University of Iowa, Iowa City, IA, 52242, USA.
| | | | - Karen L. Elliott
- Department of Biology & Department of Otolaryngology, University of Iowa, IA, USA
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4
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Size and Cycle in Dusky Salamanders. J HERPETOL 2022. [DOI: 10.1670/22-022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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5
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Pliocene origins, Pleistocene refugia, and postglacial range expansions in southern devil scorpions (Vaejovidae: Vaejovis carolinianus). ORG DIVERS EVOL 2021. [DOI: 10.1007/s13127-021-00505-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Jeon JY, Jung JH, Suk HY, Lee H, Min MS. The Asian plethodontid salamander preserves historical genetic imprints of recent northern expansion. Sci Rep 2021; 11:9193. [PMID: 33911092 PMCID: PMC8080585 DOI: 10.1038/s41598-021-88238-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 03/30/2021] [Indexed: 02/02/2023] Open
Abstract
The Korean Peninsula, located at the southern tip of Northeast Asia, has never been covered by ice sheets and was a temperate refugium during the Pleistocene. Karsenia koreana, the sole Asian plethodontid salamander species, occurs only on the southern half of the Korean Peninsula and is thought to have found various climatic refugia. Despite its phylogenetic and biogeographic importance, no population-level genetic analysis has been performed on this species. Here we study the population genetic structure of K. koreana using mitochondrial and microsatellite loci to understand the recent historical dispersion process that shaped its current distribution. Overall, the genetic distance between populations correlated well with the spatial distance, and the genetic structure among populations showed signs of a unilateral northward expansion from a southernmost refugium population. Given the distinct genetic structure formed among the populations, the level of historical gene flow among populations appears to have been very low. As the estimated effective population size of K. koreana was also small, these results suggest that the small, restricted populations of K. koreana are extremely vulnerable to environmental changes that may require high levels of genetic diversity to cope with. Thus, special management strategies are needed to preserve these remnant populations.
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Affiliation(s)
- Jong Yoon Jeon
- grid.31501.360000 0004 0470 5905Research Institute for Veterinary Science and Conservation Genome Resource Bank for Korean Wildlife, College of Veterinary Medicine, Seoul National University, Seoul, 08826 South Korea
| | - Ji-hwa Jung
- grid.31501.360000 0004 0470 5905Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826 South Korea
| | - Ho Young Suk
- grid.413028.c0000 0001 0674 4447Department of Life Sciences, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 38541 South Korea
| | - Hang Lee
- grid.31501.360000 0004 0470 5905Research Institute for Veterinary Science and Conservation Genome Resource Bank for Korean Wildlife, College of Veterinary Medicine, Seoul National University, Seoul, 08826 South Korea
| | - Mi-Sook Min
- grid.31501.360000 0004 0470 5905Research Institute for Veterinary Science and Conservation Genome Resource Bank for Korean Wildlife, College of Veterinary Medicine, Seoul National University, Seoul, 08826 South Korea
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7
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Kakehashi R, Kurabayashi A. Patterns of Natural Selection on Mitochondrial Protein-Coding Genes in Lungless Salamanders: Relaxed Purifying Selection and Presence of Positively Selected Codon Sites in the Family Plethodontidae. Int J Genomics 2021; 2021:6671300. [PMID: 33928143 PMCID: PMC8053045 DOI: 10.1155/2021/6671300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 03/12/2021] [Accepted: 03/26/2021] [Indexed: 11/18/2022] Open
Abstract
There are two distinct lungless groups in caudate amphibians (salamanders and newts) (the family Plethodontidae and the genus Onychodactylus, from the family Hynobiidae). Lunglessness is considered to have evolved in response to environmental and/or ecological adaptation with respect to oxygen requirements. We performed selection analyses on lungless salamanders to elucidate the selective patterns of mitochondrial protein-coding genes associated with lunglessness. The branch model and RELAX analyses revealed the occurrence of relaxed selection (an increase of the dN/dS ratio = ω value) in most mitochondrial protein-coding genes of plethodontid salamander branches but not in those of Onychodactylus. Additional branch model and RELAX analyses indicated that direct-developing plethodontids showed the relaxed pattern for most mitochondrial genes, although metamorphosing plethodontids had fewer relaxed genes. Furthermore, aBSREL analysis detected positively selected codons in three plethodontid branches but not in Onychodactylus. One of these three branches corresponded to the most recent common ancestor, and the others corresponded with the most recent common ancestors of direct-developing branches within Hemidactyliinae. The positive selection of mitochondrial protein-coding genes in Plethodontidae is probably associated with the evolution of direct development.
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Affiliation(s)
- Ryosuke Kakehashi
- Faculty of Bio-Science, Nagahama Institute of Bio-Science and Technology, Shiga 526-0829, Japan
| | - Atsushi Kurabayashi
- Faculty of Bio-Science, Nagahama Institute of Bio-Science and Technology, Shiga 526-0829, Japan
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
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8
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The rise and fall of globins in the amphibia. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 37:100759. [PMID: 33202310 DOI: 10.1016/j.cbd.2020.100759] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 10/23/2020] [Accepted: 10/29/2020] [Indexed: 12/28/2022]
Abstract
The globin gene repertoire of gnathostome vertebrates is dictated by differential retention and loss of nine paralogous genes: androglobin, neuroglobin, globin X, cytoglobin, globin Y, myoglobin, globin E, and the α- and β-globins. We report the globin gene repertoire of three orders of modern amphibians: Anura, Caudata, and Gymnophiona. Combining phylogenetic and conserved synteny analysis, we show that myoglobin and globin E were lost only in the Batrachia clade, but retained in Gymnophiona. The major amphibian groups also retained different paralogous copies of globin X. None of the amphibian presented αD-globin gene. Nevertheless, two clades of β-globins are present in all amphibians, indicating that the amphibian ancestor possessed two paralogous proto β-globins. We also show that orthologs of the gene coding for the monomeric hemoglobin found in the heart of Rana catesbeiana are present in Neobatrachia and Pelobatoidea species we analyzed. We suggest that these genes might perform myoglobin- and globin E-related functions. We conclude that the repertoire of globin genes in amphibians is dictated by both retention and loss of the paralogous genes cited above and the rise of a new globin gene through co-option of an α-globin, possibly facilitated by a prior event of transposition.
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9
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Jaramillo AF, De La Riva I, Guayasamin JM, Chaparro JC, Gagliardi-Urrutia G, Gutiérrez RC, Brcko I, Vilà C, Castroviejo-Fisher S. Vastly underestimated species richness of Amazonian salamanders (Plethodontidae: Bolitoglossa) and implications about plethodontid diversification. Mol Phylogenet Evol 2020; 149:106841. [PMID: 32305511 DOI: 10.1016/j.ympev.2020.106841] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 04/10/2020] [Accepted: 04/13/2020] [Indexed: 11/29/2022]
Abstract
We present data showing that the number of salamander species in Amazonia is vastly underestimated. We used DNA sequences of up to five genes (3 mitochondrial and 2 nuclear) of 366 specimens, 189 corresponding to 89 non-Amazonian nominal species and 177 Amazonian specimens, including types or topotypes, of eight of the nine recognized species in the region. By including representatives of all known species of Amazonian Bolitoglossa, except for one, and 73% of the currently 132 recognized species of the genus, our dataset represents the broadest sample of Bolitoglossa species, specimens, and geographic localities studied to date. We performed phylogenetic analyses using parsimony with tree-alignment and maximum likelihood (ML) with similarity alignment, with indels as binary characters. Our optimal topologies were used to delimit lineages that we assigned to nominal species and candidate new species following criteria that maximize the consilience of the current species taxonomy, monophyly, gaps in branch lengths, genetic distances, and geographic distribution. We contrasted the results of our species-delimitation protocol with those of Automated Barcode Gap Discovery (ABGD) and multi-rate Poisson Tree Processes (mPTP). Finally, we inferred the historical biogeography of South American salamanders by dating the trees and using dispersal-vicariance analysis (DIVA). Our results revealed a clade including almost all Amazonian salamanders, with a topology incompatible with just the currently recognized nine species. Following our species-delimitation criteria, we identified 44 putative species in Amazonia. Both ABGD and mPTP inferred more species than currently recognized, but their numbers (23-49) and limits vary. Our biogeographic analysis suggested a stepping-stone colonization of the Amazonian lowlands from Central America through the Chocó and the Andes, with several late dispersals from Amazonia back into the Andes. These biogeographic events are temporally concordant with an early land bridge between Central and South America (~10-15 MYA) and major landscape changes in Amazonia during the late Miocene and Pliocene, such as the drainage of the Pebas system, the establishment of the Amazon River, and the major orogeny of the northern Andes.
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Affiliation(s)
- Andrés F Jaramillo
- Pos-Graduação em Ecologia e Evolução da Biodiversidade, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil; Laboratorio de Sistemática de Vertebrados, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil.
| | | | - Juan M Guayasamin
- Laboratorio de Biología Evolutiva, Instituto BIOSFERA-USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Universidad San Francisco de Quito (USFQ), Ecuador; University of North Carolina at Chapel Hill, Department of Biology, USA
| | - Juan C Chaparro
- Museo de Biodiversidad del Perú (MUBI), Peru; Museo de Historia Natural de la Universidad Nacional de San Antonio Abad del Cusco, Peru
| | - Giussepe Gagliardi-Urrutia
- Pos-Graduação em Ecologia e Evolução da Biodiversidade, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil; Laboratorio de Sistemática de Vertebrados, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil; Peruvian Center for Biodiversity and Conservation (PCB&C), Peru; Dirección de Investigación en Diversidad Biológica Terrestre Amazónica, Instituto de Investigaciones de la Amazonía Peruana (IIAP), Peru
| | - Roberto C Gutiérrez
- Museo de Historia Natural de la Universidad Nacional de San Agustín de Arequipa (MUSA), Peru
| | - Isabela Brcko
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará (UFPA), Brazil
| | - Carles Vilà
- Estación Biológica de Doñana (EBD-CSIC), Spain
| | - Santiago Castroviejo-Fisher
- Pos-Graduação em Ecologia e Evolução da Biodiversidade, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil; Laboratorio de Sistemática de Vertebrados, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil; Department of Herpetology, American Museum of Natural History, USA
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10
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Scales J, Bloom SV, Deban SM. Convergently evolved muscle architecture enables high‐performance ballistic movement in salamanders. J Morphol 2019; 281:196-212. [DOI: 10.1002/jmor.21091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 11/22/2019] [Accepted: 12/02/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Jeffrey Scales
- Department of Biological Sciences, One University Circle California State University Stanislaus Turlock California
| | - Segall V. Bloom
- Department of Prosthetics VA Portland Healthcare System Portland Oregon
| | - Stephen M. Deban
- Department of Integrative Biology University of South Florida Tampa Florida
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11
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Borzée A, Andersen D, Groffen J, Kim HT, Bae Y, Jang Y. Climate change-based models predict range shifts in the distribution of the only Asian plethodontid salamander: Karsenia koreana. Sci Rep 2019; 9:11838. [PMID: 31413346 PMCID: PMC6694130 DOI: 10.1038/s41598-019-48310-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 08/02/2019] [Indexed: 11/30/2022] Open
Abstract
Populations see their range fluctuate in relation to environmental variations, including climate change, and their survival is linked to the maintenance of large enough populations and broad enough distributions during these variations. Most amphibian populations are threatened by numerous ecological and anthropogenic variables acting in synergy with climate change. Accumulating basic ecological data such as range enables the development of population and range dynamics, themselves resulting on adequate conservation plans. Karsenia koreana is the only known Asian plethodontic salamander, occurring in a very restricted area only. Based on presence data, we created an ecological model using six bioclimatic factors with low multicollinearity to define the adequate habitat of the species, and we modelled the predicted suitability of the Korean landscape following four Representative Concentration Pathways (RCPs) predicting climate change scenarios based on CO2 concentrations in 2050 and 2070. The maximum entropy model for the current distribution produced a landscape suitability considerably wider than the current known distribution. The projected ranges for each RCP indicated marked increases, decreases and shifts in areas with suitable landscapes due to climate change. The lowest RCP prediction resulted in an increase in suitable area, although potentially without connectivity with current populations, while the highest RCP predictions resulted in a decrease. Our results highlight the potential negative impact of climate change, thus requiring updates in conservation plans for K. koreana. The methods used here can be replicated with any land-dwelling species, and our results reflect expected range shifts for most amphibians of the northern hemisphere.
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Affiliation(s)
- Amaël Borzée
- Department of Life Science and Division of EcoScience, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Desiree Andersen
- Department of Life Science and Division of EcoScience, Ewha Womans University, Seoul, 03760, Republic of Korea
- Interdisciplinary Program of EcoCreative, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Jordy Groffen
- Department of Life Science and Division of EcoScience, Ewha Womans University, Seoul, 03760, Republic of Korea
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Hyun-Tae Kim
- Seosan Joongang High School, Seosan, South Chungcheon Province, Republic of Korea
| | - Yoonhyuk Bae
- Department of Life Science and Division of EcoScience, Ewha Womans University, Seoul, 03760, Republic of Korea
- Department of Life Science, College of Natural Science, Hallym University, Chuncheon, Republic of Korea
| | - Yikweon Jang
- Department of Life Science and Division of EcoScience, Ewha Womans University, Seoul, 03760, Republic of Korea.
- Interdisciplinary Program of EcoCreative, Ewha Womans University, Seoul, 03760, Republic of Korea.
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12
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Camp CD, Soelter TM, Wooten JA. Sexual selection and male-biased size dimorphism in a lineage of lungless salamander (Ampibia: Plethodontidae). Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Evolutionary biologists have long focused on the patterns and causes of sexual size dimorphism (SSD). While female-biased SSD is common among ectotherms, a few lineages predominately exhibit male-biased SSD. One example is the clade of desmognathans, a monophyletic group of two genera within the Plethodontinae of the lungless salamander family Plethodontidae. Members of these two genera have a unique pattern of SSD: males mature earlier and at smaller sizes than females but reach greater maximum sizes. We used comparative phylogenetic methods to test whether SSD in these salamanders is the result of sexual selection on males. Spatial evolutionary and ecological vicariance analysis indicated a significant divergence in SSD associated with the phylogenetic origin of the desmognathans. Phylogenetic least-squares regression across the two most speciose genera of the subfamily determined a significant relationship between SSD and adult sex ratio. While male desmognathans are not sexually dimorphic in head size, they have a unique head morphology that causes their heads to grow more rapidly as their body size increases as compared with the heads of other salamanders. This pattern of allometric growth combines with a powerful bite force and enlarged premaxillary teeth to create formidable weaponry that probably is more responsive to sexual selection.
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Affiliation(s)
- Carlos D Camp
- Department of Biology, Piedmont College, Demorest, GA, USA
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13
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Kuchta SR. Richard Highton. COPEIA 2019. [DOI: 10.1643/ot-19-224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Shawn R. Kuchta
- Ohio Center for Ecological and Evolutionary Studies, Department of Biological Sciences, Ohio University, Irvine 107, Athens, Ohio 45701;
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14
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Park J, Choi WJ, Kim IH, Park D. Complete mitochondrial genome of the Korean crevice salamander ( Karsenia koreana) (Amphibia, Urodela: Plethodontidae). Mitochondrial DNA B Resour 2019. [DOI: 10.1080/23802359.2019.1601530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Jaejin Park
- Division of Science Education, Kangwon National University, Chuncheon, Kangwon, South Korea
| | - Woo-Jin Choi
- Department of Biology, Kangwon National University, Chuncheon, Kangwon, South Korea
| | - Il-Hun Kim
- Department of Ecology and Conservation, Marine Biodiversity Institute of Korea, Seochun, Chungnam, South Korea
| | - Daesik Park
- Division of Science Education, Kangwon National University, Chuncheon, Kangwon, South Korea
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15
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Chong RA, Mueller RL. Polymorphic duplicate genes and persistent non-coding sequences reveal heterogeneous patterns of mitochondrial DNA loss in salamanders. BMC Genomics 2017; 18:992. [PMID: 29281973 PMCID: PMC5745709 DOI: 10.1186/s12864-017-4358-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 11/29/2017] [Indexed: 12/03/2022] Open
Abstract
Background Mitochondria are the site of the citric acid cycle and oxidative phosphorylation (OXPHOS). In metazoans, the mitochondrial genome is a small, circular molecule averaging 16.5 kb in length. Despite evolutionarily conserved gene content, metazoan mitochondrial genomes show a diversity of gene orders most commonly explained by the duplication-random loss (DRL) model. In the DRL model, (1) a sequence of genes is duplicated in tandem, (2) one paralog sustains a loss-of-function mutation, resulting in selection to retain the other copy, and (3) the non-functional paralog is eventually deleted from the genome. Despite its apparent role in generating mitochondrial gene order diversity, little is known about the tempo and mode of random gene loss after duplication events. Here, we determine mitochondrial gene order across the salamander genus Aneides, which was previously shown to include at least two DRL-mediated rearrangement events. We then analyze these gene orders in a phylogenetic context to reveal patterns of DNA loss after mitochondrial gene duplication. Results We identified two separate duplication events that resulted in mitochondrial gene rearrangements in Aneides; one occurred at the base of the clade tens of millions of years ago, while the other occurred much more recently (i.e. within a single species), resulting in gene order polymorphism and paralogs that are readily identifiable. We demonstrate that near-complete removal of duplicate rRNA genes has occurred since the recent duplication event, whereas duplicate protein-coding genes persist as pseudogenes and duplicate tRNAs persist as functionally intact paralogs. In addition, we show that non-coding DNA duplicated at the base of the clade has persisted across species for tens of millions of years. Conclusions The evolutionary history of the mitochondrial genome, from its inception as a bacterial endosymbiont, includes massive genomic reduction. Consistent with this overall trend, selection for efficiency of mitochondrial replication and transcription has been hypothesized to favor elimination of extra sequence. Our results, however, suggest that there may be no strong disadvantage to extraneous sequences in salamander mitochondrial genomes, although duplicate rRNA genes may be deleterious. Electronic supplementary material The online version of this article (10.1186/s12864-017-4358-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rebecca A Chong
- Department of Biology, Colorado State University, Fort Collins, CO, 80523-1878, USA. .,Present address: Department of Biology, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA.
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Dawley EM. Comparative Morphology of Plethodontid Olfactory and Vomeronasal Organs: How Snouts Are Packed. HERPETOLOGICAL MONOGRAPHS 2017. [DOI: 10.1655/herpmonographs-d-15-00008.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Ellen M. Dawley
- Department of Biology, Ursinus College, Collegeville, PA 19426, USA
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17
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Affiliation(s)
- Kenneth H. Kozak
- Bell Museum of Natural History and Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, St. Paul, MN 55108, USA
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18
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Affiliation(s)
- David B. Wake
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720-3160, USA
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19
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Sever DM, Pinsoneault AD, Mackenzie BW, Siegel DS, Staub NL. A Description of the Skin Glands and Cloacal Morphology of the Plethodontid SalamanderKarsenia koreana. COPEIA 2016. [DOI: 10.1643/cg-16-468] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Parra-Olea G, Rovito SM, García-París M, Maisano JA, Wake DB, Hanken J. Biology of tiny animals: three new species of minute salamanders (Plethodontidae: Thorius) from Oaxaca, Mexico. PeerJ 2016; 4:e2694. [PMID: 27896029 PMCID: PMC5119241 DOI: 10.7717/peerj.2694] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 10/16/2016] [Indexed: 11/20/2022] Open
Abstract
We describe three new species of minute salamanders, genus Thorius, from the Sierra Madre del Sur of Oaxaca, Mexico. Until now only a single species, T. minutissimus, has been reported from this region, although molecular data have long shown extensive genetic differentiation among geographically disjunct populations. Adult Thorius pinicola sp. nov., T. longicaudus sp. nov., and T. tlaxiacus sp. nov. are larger than T. minutissimus and possess elliptical rather than oval nostrils; T. pinicola and T. longicaudus also have longer tails. All three new species occur west of the range of T. minutissimus, which has the easternmost distribution of any member of the genus. The new species are distinguished from each other and from other named Thorius in Oaxaca by a combination of adult body size, external morphology and osteology, and by protein characters (allozymes) and differences in DNA sequences. In addition, we redescribe T. minutissimus and a related species, T. narisovalis, to further clarify the taxonomic status of Oaxacan populations and to facilitate future studies of the remaining genetically differentiated Thorius that cannot be satisfactorily assigned to any named species. Populations of all five species considered here appear to have declined dramatically over the last one or two decades and live specimens are difficult to find in nature. Thorius may be the most endangered genus of amphibians in the world. All species may go extinct before the end of this century.
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Affiliation(s)
- Gabriela Parra-Olea
- Instituto de Biología, Universidad Nacional Autónoma de México , Mexico City , Mexico
| | - Sean M Rovito
- Unidad de Genómica Avanzada (Langebio), CINVESTAV , Irapuato, Guanajuato , Mexico
| | - Mario García-París
- Departamento de Biodiversidad y Biologia Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC) , Madrid , Spain
| | - Jessica A Maisano
- Jackson School of Geosciences, University of Texas at Austin , Austin, Texas , United States
| | - David B Wake
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California , Berkeley, California , United States
| | - James Hanken
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University , Cambridge, Massachusetts , United States
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21
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Scales JA, Stinson CM, Deban SM. Extreme Performance and Functional Robustness of Movement are Linked to Muscle Architecture: Comparing Elastic and Nonelastic Feeding Movements in Salamanders. ACTA ACUST UNITED AC 2016; 325:360-76. [DOI: 10.1002/jez.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/16/2016] [Accepted: 05/17/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Jeffrey A. Scales
- Department of Integrative Biology University of South Florida Tampa Florida
| | | | - Stephen M. Deban
- Department of Integrative Biology University of South Florida Tampa Florida
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22
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Abstract
Mental glands and their associated delivery behaviors during courtship are unique to the plethodontid salamanders. Because previous interpretations of the evolution of these features were conducted using older phylogenetic hypotheses, we reanalyzed these traits with newer courtship descriptions and contemporary phylogenetic methods. Using Bayesian ancestral state reconstruction methods that have been developed since the first phylogenetic analyses were conducted in the mid-1990s, we reconstructed mental gland and courtship behavior evolution on a Bayesian phylogeny of the nuclear gene Rag1. The most probable ancestral condition for plethodontids was resolved as presence of a mental gland. Loss of a mental gland occurred in each subfamily and was recovered as the most probable ancestral condition for the Spelerpinae. In contrast, parsimony reconstruction recovered the presence of a mental gland in the ancestor to Spelerpinae with multiple secondary losses. We hypothesize that that absence of a mental gland is possibly ancestral in some clades (i.e., Spelerpinae) and secondary in others (e.g., paedomorphic Eurycea). The most probable ancestral form of the mental gland is likely to be the large pad-type distributed extensively in Plethodontinae and Bolitoglossinae. Desmognathans have the most unique mental glands, occurring in an anterior protrusion or bifurcated form (in Desmognathus wrighti). Fan-shaped mental glands evolved independently in Eurycea and Oedipina. Small pads arose independently in Bolitoglossinae, Plethodontinae, and Spelerpinae. Head-rubbing behavior for mental gland delivery mode was recovered as the most probable and parsimonious ancestral state for the Plethodontidae, with independent losses of this behavior in Plethodontinae and Spelerpinae. Because head-rubbing was observed in outgroups, we hypothesize that head-rubbing behavior predated mental gland evolution. Pulling, snapping, slapping, and biting behaviors evolved independently in the Plethodontinae and Spelerpinae and are not homologous with head-rubbing. All hypotheses of mental gland and courtship evolution invoke homoplasy.
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Affiliation(s)
- David M Sever
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana 70402
| | - Dustin S Siegel
- Department of Biology, Southeast Missouri State University, Cape Girardeau, Missouri 63701
| | - Michael S Taylor
- Department of Biology, Southeast Missouri State University, Cape Girardeau, Missouri 63701
| | - Christopher K Beachy
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana 70402
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23
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Kuchta SR, Brown AD, Converse PE, Highton R. Multilocus Phylogeography and Species Delimitation in the Cumberland Plateau Salamander, Plethodon kentucki: Incongruence among Data Sets and Methods. PLoS One 2016; 11:e0150022. [PMID: 26974148 PMCID: PMC4790894 DOI: 10.1371/journal.pone.0150022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Accepted: 02/08/2016] [Indexed: 11/29/2022] Open
Abstract
Species are a fundamental unit of biodiversity, yet can be challenging to delimit objectively. This is particularly true of species complexes characterized by high levels of population genetic structure, hybridization between genetic groups, isolation by distance, and limited phenotypic variation. Previous work on the Cumberland Plateau Salamander, Plethodon kentucki, suggested that it might constitute a species complex despite occupying a relatively small geographic range. To examine this hypothesis, we sampled 135 individuals from 43 populations, and used four mitochondrial loci and five nuclear loci (5693 base pairs) to quantify phylogeographic structure and probe for cryptic species diversity. Rates of evolution for each locus were inferred using the multidistribute package, and time calibrated gene trees and species trees were inferred using BEAST 2 and *BEAST 2, respectively. Because the parameter space relevant for species delimitation is large and complex, and all methods make simplifying assumptions that may lead them to fail, we conducted an array of analyses. Our assumption was that strongly supported species would be congruent across methods. Putative species were first delimited using a Bayesian implementation of the GMYC model (bGMYC), Geneland, and Brownie. We then validated these species using the genealogical sorting index and BPP. We found substantial phylogeographic diversity using mtDNA, including four divergent clades and an inferred common ancestor at 14.9 myr (95% HPD: 10.8–19.7 myr). By contrast, this diversity was not corroborated by nuclear sequence data, which exhibited low levels of variation and weak phylogeographic structure. Species trees estimated a far younger root than did the mtDNA data, closer to 1.0 myr old. Mutually exclusive putative species were identified by the different approaches. Possible causes of data set discordance, and the problem of species delimitation in complexes with high levels of population structure and introgressive hybridization, are discussed.
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Affiliation(s)
- Shawn R. Kuchta
- Department of Biological Sciences, Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio, United States of America
- * E-mail:
| | - Ashley D. Brown
- Department of Biological Sciences, Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio, United States of America
| | - Paul E. Converse
- Department of Biological Sciences, Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio, United States of America
| | - Richard Highton
- Department of Biology, University of Maryland, College Park, Maryland, United States of America
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24
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25
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Performance evaluation of dominance-based and indicator-based multiobjective approaches for phylogenetic inference. Inf Sci (N Y) 2016. [DOI: 10.1016/j.ins.2015.10.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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26
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Scales JA, O'Donnell MK, Deban SM. Thermal sensitivity of motor control of muscle-powered versus elastically powered tongue projection in salamanders. J Exp Biol 2016; 220:938-951. [DOI: 10.1242/jeb.145896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/06/2016] [Indexed: 11/20/2022]
Abstract
Elastic-recoil mechanisms can improve organismal performance and circumvent the thermal limitations of muscle contraction, yet they require the appropriate motor control to operate. We compare muscle activity during tongue projection in salamanders with elastically powered, ballistic projection to those with muscle-powered, non-ballistic projection across a range of temperatures to understand how motor control is integrated with elastically powered movements, and how this integration contributes to reduced thermal sensitivity. Species with ballistic tongue projection activated and deactivated their projector muscles significantly earlier than non-ballistic species, in a pattern consistent with a mechanism in which the muscle strains elastic tissue that subsequently recoils to power projection. Tongue projection was more thermally robust in ballistic species, but in both ballistic and non-ballistic species the projector muscles were activated earlier and for longer as temperature decreased. The retractor muscles showed a similar pattern as the projector muscles, but declined in a similar manner in the two groups. Muscle activity intensity also decreased at low temperatures in both groups, revealing that compensatory muscle activation does not account for the improved thermal robustness in ballistic species. Thus, relatively minor shifts in motor patterns accompanying morphological changes such as increased elastic tissue are sufficient to improve performance and decrease its thermal sensitivity without specialization of muscle contractile physiology.
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Affiliation(s)
- Jeffrey A. Scales
- Department of Biological Sciences, One University Circle, California State University, Stanislaus, Turlock, CA, 95382, USA
| | - Mary Kate O'Donnell
- Department of Integrative Biology, 4202 East Fowler Avenue, Science Center 110, University of South Florida, Tampa, FL, 33620, USA
| | - Stephen M. Deban
- Department of Integrative Biology, 4202 East Fowler Avenue, Science Center 110, University of South Florida, Tampa, FL, 33620, USA
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27
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Kundrát M. Great Transformations in Vertebrate Evolution.— Edited by Kenneth P. Dial, Neil Shubin, and Elizabeth L. Brainerd. Syst Biol 2015. [DOI: 10.1093/sysbio/syv117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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28
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Santander-Jiménez S, Vega-Rodríguez MA. On the design of shared memory approaches to parallelize a multiobjective bee-inspired proposal for phylogenetic reconstruction. Inf Sci (N Y) 2015. [DOI: 10.1016/j.ins.2015.06.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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29
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Shen XX, Liang D, Chen MY, Mao RL, Wake DB, Zhang P. Enlarged Multilocus Data set Provides Surprisingly Younger Time of Origin for the Plethodontidae, the Largest Family of Salamanders. Syst Biol 2015; 65:66-81. [PMID: 26385618 DOI: 10.1093/sysbio/syv061] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 08/15/2015] [Indexed: 11/14/2022] Open
Abstract
Deep phylogenetic relationships of the largest salamander family Plethodontidae have been difficult to resolve, probably reflecting a rapid diversification early in their evolutionary history. Here, data from 50 independent nuclear markers (total 48,582 bp) are used to reconstruct the phylogeny and divergence times for plethodontid salamanders, using both concatenation and coalescence-based species tree analyses. Our results robustly resolve the position of the enigmatic eastern North American four-toed salamander (Hemidactylium) as the sister taxon of Batrachoseps + Tribe Bolitoglossini, thus settling a long-standing question. Furthermore, we statistically reject sister taxon status of Karsenia and Hydromantes, the only plethodontids to occur outside the Americas, leading us to new biogeographic hypotheses. Contrary to previous long-standing arguments that plethodontid salamanders are an old lineage originating in the Cretaceous (more than 90 Ma), our analyses lead to the hypothesis that these salamanders are much younger, arising close to the K-T boundary (~66 Ma). These time estimates are highly stable using alternative calibration schemes and dating methods. Our data simulation highlights the potential risk of making strong arguments about phylogenetic timing based on inferences from a handful of nuclear genes, a common practice. Based on the newly obtained timetree and ancestral area reconstruction results, we argue that (i) the classic "Out of Appalachia" hypothesis of plethodontid origins is problematic; (ii) the common ancestor of extant plethodontids may have originated in northwestern North America in the early Paleocene; (iii) origins of Eurasian plethodontids likely result from two separate dispersal events from western North America via Beringia in the late Eocene (~42 Ma) and the early Miocene (~23 Ma), respectively.
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Affiliation(s)
- Xing-Xing Shen
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China and
| | - Dan Liang
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China and
| | - Meng-Yun Chen
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China and
| | - Rong-Li Mao
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China and
| | - David B Wake
- Museum of Vertebrate Zoology and Department of Integrative Biology, 3101 Valley Life Sciences Bldg, University of California, Berkeley, CA 94720, USA
| | - Peng Zhang
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China and
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30
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Rovito SM, Parra-Olea G, Recuero E, Wake DB. Diversification and biogeographical history of Neotropical plethodontid salamanders. Zool J Linn Soc 2015. [DOI: 10.1111/zoj.12271] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sean M. Rovito
- Museum of Vertebrate Zoology; University of California; 3101 Valley Life Sciences Building Berkeley CA 94720-3160 USA
- Instituto de Biología; Universidad Nacional Autónoma de México; AP 70-153 Circuito Exterior Ciudad Universitaria México DF CP 04510 México
| | - Gabriela Parra-Olea
- Instituto de Biología; Universidad Nacional Autónoma de México; AP 70-153 Circuito Exterior Ciudad Universitaria México DF CP 04510 México
| | - Ernesto Recuero
- Departamento de Ecología de la Biodiversidad; Instituto de Ecología; Universidad Nacional Autónoma de México; AP 70-275 Ciudad Universitaria México DF 04510 Mexico
| | - David B. Wake
- Museum of Vertebrate Zoology; University of California; 3101 Valley Life Sciences Building Berkeley CA 94720-3160 USA
- Department of Integrative Biology; University of California; 3040 Valley Life Sciences Building Berkeley CA 94720-3140 USA
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31
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Fisher-Reid MC, Wiens JJ. Is geographic variation within species related to macroevolutionary patterns between species? J Evol Biol 2015; 28:1502-15. [PMID: 26079479 DOI: 10.1111/jeb.12670] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/19/2015] [Accepted: 06/10/2015] [Indexed: 01/01/2023]
Abstract
The relationship between microevolution and macroevolution is a central topic in evolutionary biology. An aspect of this relationship that remains very poorly studied in modern evolutionary biology is the relationship between within-species geographic variation and among-species patterns of trait variation. Here, we tested the relationship between climate and morphology among and within species in the salamander genus Plethodon. We focus on a discrete colour polymorphism (presence and absence of a red dorsal stripe) that appears to be related to climatic distributions in a common, wide-ranging species (Plethodon cinereus). We find that this trait has been variable among (and possibly within) species for >40 million years. Furthermore, we find a strong relationship among species between climatic variation and within-species morph frequencies. These between-species patterns are similar (but not identical) to those in the broadly distributed Plethodon cinereus. Surprisingly, there are no significant climate-morphology relationships within most other polymorphic species, despite the strong between-species patterns. Overall, our study provides an initial exploration of how within-species geographic variation and large-scale macroevolutionary patterns of trait variation may be related.
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Affiliation(s)
- M C Fisher-Reid
- Department of Biological Sciences, Bridgewater State University, Bridgewater, MA, USA
| | - J J Wiens
- Department of Ecology and Evolution, University of Arizona, Tucson, AZ, USA
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Normal table of embryonic development in the four-toed salamander, Hemidactylium scutatum. Mech Dev 2015; 136:99-110. [PMID: 25617760 DOI: 10.1016/j.mod.2014.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 11/30/2014] [Accepted: 12/31/2014] [Indexed: 11/22/2022]
Abstract
We present a complete staging table of normal development for the lungless salamander, Hemidactylium scutatum (Caudata: Plethodontidae). Terrestrial egg clutches from naturally ovipositing females were collected and maintained at 15 °C in the laboratory. Observations, photographs, and time-lapse movies of embryos were taken throughout the 45-day embryonic period. The complete normal table of development for H. scutatum is divided into 28 stages and extends previous analyses of H. scutatum embryonic development (Bishop, 1920; Humphrey, 1928). Early embryonic stage classifications through neurulation reflect criteria described for Xenopus laevis, Ambystoma maculatum and other salamanders. Later embryonic stage assignments are based on unique features of H. scutatum embryos. Additionally, we provide morphological analysis of gastrulation and neurulation, as well as details on external aspects of eye, gill, limb, pigmentation, and tail development to support future research related to phylogeny, comparative embryology, and molecular mechanisms of development.
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33
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Deban SM, Scales JA. Dynamics and thermal sensitivity of ballistic and non-ballistic feeding in salamanders. J Exp Biol 2015; 219:431-44. [DOI: 10.1242/jeb.127407] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 11/17/2015] [Indexed: 11/20/2022]
Abstract
Low temperature reduces the performance of muscle-powered movements, but in movements powered by elastic-recoil mechanisms, this effect can be mitigated and performance can be increased. To better understand the morphological basis of high performance and thermal robustness of elastically powered movements, we compared feeding dynamics at a range of temperatures (5-25°C) in two species of terrestrial plethodontid salamanders, Plethodon metcalfi and Ensatina eschscholtzii, which differ in tongue muscle architecture and the mechanism of tongue projection. We found that Ensatina is capable of ballistic projection with a mean muscle-mass-specific power of 2100 W kg−1, revealing an elastic mechanism. Plethodon, in contrast, projected its tongue non-ballistically with a mean power of only 18 W kg−1, indicating it is muscle-powered. Ensatina projected the tongue significantly farther than Plethodon and with dynamics that had significantly lower thermal sensitivity at temperatures below 15°C. These performance differences were correlated with morphological differences, namely elongated collagenous aponeuroses in the projector muscle of Ensatina as compared to Plethodon which are likely the site of energy storage, and the absence in Ensatina of projector muscle fibers attaching to the tongue skeleton that allows projection to be truly ballistic. These findings demonstrate that, in these otherwise similar species, the presence in one species of elaborated connective tissue in series with myofibers confers not only 10-fold greater absolute performance but also greater thermal robustness of performance. We conclude that changes in muscle and connective-tissue architecture are sufficient to alter significantly the mechanics, performance and thermal robustness of musculoskeletal systems.
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Affiliation(s)
- Stephen M. Deban
- Department of Integrative Biology, 4202 East Fowler Avenue, Science Center 110, University of South Florida, Tampa, Florida, 33620, USA
| | - Jeffrey A. Scales
- Department of Integrative Biology, 4202 East Fowler Avenue, Science Center 110, University of South Florida, Tampa, Florida, 33620, USA
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34
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Abstract
SummaryThe order Caudata includes about 660 species and displays a variety of important developmental traits such as cleavage pattern and egg size. However, the cleavage process of tailed amphibians has never been analyzed within a phylogenetic framework. We use published data on the embryos of 36 species concerning the character of the third cleavage furrow (latitudinal, longitudinal or variable) and the magnitude of synchronous cleavage period (up to 3–4 synchronous cell divisions in the animal hemisphere or a considerably longer series of synchronous divisions followed by midblastula transition). Several species from basal caudate families Cryptobranchidae (Andrias davidianus and Cryptobranchus alleganiensis) and Hynobiidae (Onychodactylus japonicus) as well as several representatives from derived families Plethodontidae (Desmognathus fuscus and Ensatina eschscholtzii) and Proteidae (Necturus maculosus) are characterized by longitudinal furrows of the third cleavage and the loss of synchrony as early as the 8-cell stage. By contrast, many representatives of derived families Ambystomatidae and Salamandridae have latitudinal furrows of the third cleavage and extensive period of synchronous divisions. Our analysis of these ontogenetic characters mapped onto a phylogenetic tree shows that the cleavage pattern of large, yolky eggs with short series of synchronous divisions is an ancestral trait for the tailed amphibians, while the data on the orientation of third cleavage furrows seem to be ambiguous with respect to phylogeny. Nevertheless, the midblastula transition, which is characteristic of the model species Ambystoma mexicanum (Caudata) and Xenopus laevis (Anura), might have evolved convergently in these two amphibian orders.
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Siegel DS, Alvino S, Trauth SE, Sever DM, Gribbins KM. Spermatogenic cycle of a plethodontid salamander, Eurycea longicauda (Amphibia, Urodela). SPERMATOGENESIS 2014; 4:e982420. [PMID: 26413402 PMCID: PMC4581059 DOI: 10.4161/21565562.2014.982420] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 10/21/2014] [Accepted: 10/28/2014] [Indexed: 11/19/2022]
Abstract
Previous investigators have described the spermatogenic cycles of numerous species of plethodontid salamanders. Most studies describe a fairly stereotypical cycle with meiotic divisions of spermatogenesis commencing in the spring/summer. However, many studies lack details obtainable from histological examination and/or testicular squashes and, instead, provide only mensural data from the testes. Studies that lacked microscopic evaluation often revealed spermatogenic cycles that varied greatly from that of the stereotypical cycle with meiotic divisions commencing in the fall/winter. Those studies hamper comparisons between the spermatogenic cycles of different species and their environments, as they do not provide a correlation between testicular size and any aspect of the spermatogenic cycle. In the following manuscript, we elucidate the spermatogenic cycle of Eurycea longicauda longicauda in an effort to outline an appropriate protocol for analyzing spermatogenesis in salamanders that will facilitate future comparative studies. Like many Nearctic plethodontids, E. l. longicauda exhibits a meiotic wave that travels through the testes during the summer; this process is followed by spermiogenesis, spermiation, and recrudescence in the fall, winter, and spring.
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Affiliation(s)
- Dustin S Siegel
- Department of Biology; Southeast Missouri State University; Cape Girardeau, MO USA
| | - Sam Alvino
- Department of Biology; Southeast Missouri State University; Cape Girardeau, MO USA
| | - Stanley E Trauth
- Department of Biological Sciences; Arkansas State University; State University, AR USA
| | - David M Sever
- Department of Biological Sciences; Southeastern Louisiana University; Hammond, LA USA
| | - Kevin M Gribbins
- Department of Biology; University of Indianapolis; Indianapolis, IN USA
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36
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Anderson CV, Larghi NP, Deban SM. Thermal effects on the performance, motor control, and muscle dynamics of ballistic feeding in the salamander Eurycea guttolineata. J Exp Biol 2014; 217:3146-58. [DOI: 10.1242/jeb.105437] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Temperature strongly affects muscle contractile rate properties and thus may influence whole-organism performance. Movements powered by elastic recoil, however, are known to be more thermally robust than muscle-powered movements. We examined the whole-organism performance, motor control and muscle contractile physiology underlying feeding in the salamander Eurycea guttolineata. We compared elastically powered tongue projection to the associated muscle-powered retraction to determine the thermal robustness of each of these functional levels. We found that tongue-projection distance in Eurycea was unaffected by temperature across the entire 4-26°C range, tongue-projection dynamics were significantly affected by temperature across only the 4-11°C interval, and tongue retraction was affected to a higher degree across the entire temperature range. The significant effect of temperature on projection dynamics across the 4-11°C interval corresponds to a significant decline in projector muscle burst intensity and peak contractile force of the projector muscle across the same interval. Across the remaining temperature range, however, projection dynamics were unaffected by temperature with contractile muscle physiology showing typical thermal effects and motor patterns showing increased activity durations and latencies. These results reveal that elastically powered tongue-projection performance in Eurycea is maintained to a higher degree than muscle-powered tongue retraction performance across a wide temperature range. These results further indicate that thermal robustness of the elastically powered movement is dependent on motor control and muscle physiology that results in comparable energy being stored in elastic tissues across a range of temperatures.
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37
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Griesemer J. Integration of approaches in David Wake's model-taxon research platform for evolutionary morphology. STUDIES IN HISTORY AND PHILOSOPHY OF BIOLOGICAL AND BIOMEDICAL SCIENCES 2013; 44:525-536. [PMID: 23588059 DOI: 10.1016/j.shpsc.2013.03.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
What gets integrated in integrative scientific practices has been a topic of much discussion. Traditional views focus on theories and explanations, with ideas of reduction and unification dominating the conversation. More recent ideas focus on disciplines, fields, or specialties; models, mechanisms, or methods; phenomena, problems. How integration works looks different on each of these views since the objects of integration are ontologically and epistemically various: statements, boundary conditions, practices, protocols, methods, variables, parameters, domains, laboratories, and questions all have their own structures, functions and logics. I focus on one particular kind of scientific practice, integration of "approaches" in the context of a research system operating on a special kind of "platform." Rather than trace a network of interactions among people, practices, and theoretical entities to be integrated, in this essay I focus on the work of a single investigator, David Wake. I describe Wake's practice of integrative evolutionary biology and how his integration of approaches among biological specialties worked in tandem with his development of the salamanders as a model taxon, which he used as a platform to solve, re-work and update problems that would not have been solved so well by non-integrative approaches. The larger goal of the project to which this paper contributes is a counter-narrative to the story of 20th century life sciences as the rise and march of the model organisms and decline of natural history.
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Affiliation(s)
- James Griesemer
- Department of Philosophy, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States.
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Santander-Jiménez S, Vega-Rodríguez MA. Applying a multiobjective metaheuristic inspired by honey bees to phylogenetic inference. Biosystems 2013; 114:39-55. [DOI: 10.1016/j.biosystems.2013.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/17/2013] [Accepted: 07/02/2013] [Indexed: 10/26/2022]
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39
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Blackburn DC, Siler CD, Diesmos AC, McGuire JA, Cannatella DC, Brown RM. An adaptive radiation of frogs in a southeast Asian island archipelago. Evolution 2013; 67:2631-46. [PMID: 24033172 PMCID: PMC3920640 DOI: 10.1111/evo.12145] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 04/10/2013] [Indexed: 11/30/2022]
Abstract
Living amphibians exhibit a diversity of ecologies, life histories, and species-rich lineages that offers opportunities for studies of adaptive radiation. We characterize a diverse clade of frogs (Kaloula, Microhylidae) in the Philippine island archipelago as an example of an adaptive radiation into three primary habitat specialists or ecotypes. We use a novel phylogenetic estimate for this clade to evaluate the tempo of lineage accumulation and morphological diversification. Because species-level phylogenetic estimates for Philippine Kaloula are lacking, we employ dense population sampling to determine the appropriate evolutionary lineages for diversification analyses. We explicitly take phylogenetic uncertainty into account when calculating diversification and disparification statistics and fitting models of diversification. Following dispersal to the Philippines from Southeast Asia, Kaloula radiated rapidly into several well-supported clades. Morphological variation within Kaloula is partly explained by ecotype and accumulated at high levels during this radiation, including within ecotypes. We pinpoint an axis of morphospace related directly to climbing and digging behaviors and find patterns of phenotypic evolution suggestive of ecological opportunity with partitioning into distinct habitat specialists. We conclude by discussing the components of phenotypic diversity that are likely important in amphibian adaptive radiations.
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Affiliation(s)
- David C Blackburn
- Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, Kansas, 66045; Current address: Department of Vertebrate Zoology and Anthropology, California Academy of Sciences, San Francisco, California, 94118.
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Sun C, López Arriaza JR, Mueller RL. Slow DNA loss in the gigantic genomes of salamanders. Genome Biol Evol 2013; 4:1340-8. [PMID: 23175715 PMCID: PMC3542557 DOI: 10.1093/gbe/evs103] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Evolutionary changes in genome size result from the combined effects of mutation, natural
selection, and genetic drift. Insertion and deletion mutations (indels) directly impact
genome size by adding or removing sequences. Most species lose more DNA through small
indels (i.e., ∼1–30 bp) than they gain, which can result in genome reduction
over time. Because this rate of DNA loss varies across species, small indel dynamics have
been suggested to contribute to genome size evolution. Species with extremely large
genomes provide interesting test cases for exploring the link between small indels and
genome size; however, most large genomes remain relatively unexplored. Here, we examine
rates of DNA loss in the tetrapods with the largest genomes—the salamanders. We used
low-coverage genomic shotgun sequence data from four salamander species to examine
patterns of insertion, deletion, and substitution in neutrally evolving non-long terminal
repeat (LTR) retrotransposon sequences. For comparison, we estimated genome-wide DNA loss
rates in non-LTR retrotransposon sequences from five other vertebrate genomes:
Anolis carolinensis, Danio rerio, Gallus
gallus, Homo sapiens, and Xenopus tropicalis.
Our results show that salamanders have significantly lower rates of DNA loss than do other
vertebrates. More specifically, salamanders experience lower numbers of deletions relative
to insertions, and both deletions and insertions are skewed toward smaller sizes. On the
basis of these patterns, we conclude that slow DNA loss contributes to genomic gigantism
in salamanders. We also identify candidate molecular mechanisms underlying these
differences and suggest that natural variation in indel dynamics provides a unique
opportunity to study the basis of genome stability.
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Affiliation(s)
- Cheng Sun
- Department of Biology, Colorado State University, CO, USA
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41
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Pasmans F, Van Rooij P, Blooi M, Tessa G, Bogaerts S, Sotgiu G, Garner TWJ, Fisher MC, Schmidt BR, Woeltjes T, Beukema W, Bovero S, Adriaensen C, Oneto F, Ottonello D, Martel A, Salvidio S. Resistance to chytridiomycosis in European plethodontid salamanders of the genus Speleomantes. PLoS One 2013; 8:e63639. [PMID: 23703511 PMCID: PMC3659026 DOI: 10.1371/journal.pone.0063639] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 04/04/2013] [Indexed: 11/18/2022] Open
Abstract
North America and the neotropics harbor nearly all species of plethodontid salamanders. In contrast, this family of caudate amphibians is represented in Europe and Asia by two genera, Speleomantes and Karsenia, which are confined to small geographic ranges. Compared to neotropical and North American plethodontids, mortality attributed to chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) has not been reported for European plethodontids, despite the established presence of Bd in their geographic distribution. We determined the extent to which Bd is present in populations of all eight species of European Speleomantes and show that Bd was undetectable in 921 skin swabs. We then compared the susceptibility of one of these species, Speleomantes strinatii, to experimental infection with a highly virulent isolate of Bd (BdGPL), and compared this to the susceptible species Alytes muletensis. Whereas the inoculated A. muletensis developed increasing Bd-loads over a 4-week period, none of five exposed S. strinatii were colonized by Bd beyond 2 weeks post inoculation. Finally, we determined the extent to which skin secretions of Speleomantes species are capable of killing Bd. Skin secretions of seven Speleomantes species showed pronounced killing activity against Bd over 24 hours. In conclusion, the absence of Bd in Speleomantes combined with resistance to experimental chytridiomycosis and highly efficient skin defenses indicate that the genus Speleomantes is a taxon unlikely to decline due to Bd.
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Affiliation(s)
- Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Rovito SM, Parra-Olea G, Hanken J, Bonett RM, Wake DB. Adaptive radiation in miniature: the minute salamanders of the Mexican highlands (Amphibia: Plethodontidae:Thorius). Biol J Linn Soc Lond 2013. [DOI: 10.1111/bij.12083] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Gabriela Parra-Olea
- Departamento de Zoología; Instituto de Biología; Universidad Nacional Autónoma de México; AP 70-153, CP 04510, Ciudad Universitaria; México; D.F.; México
| | - James Hanken
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology; Harvard University; 26 Oxford St.; Cambridge; MA; 02138; USA
| | - Ronald M. Bonett
- Department of Biological Science; University of Tulsa; 800 S Tucker Drive; Tulsa; OK; 74104; USA
| | - David B. Wake
- Department of Integrative Biology and Museum of Vertebrate Zoology; University of California; Berkeley; CA; 94720-3160; USA
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Machac A, Zrzavý J, Smrckova J, Storch D. Temperature dependence of evolutionary diversification: differences between two contrasting model taxa support the metabolic theory of ecology. J Evol Biol 2012; 25:2449-56. [PMID: 23116407 DOI: 10.1111/jeb.12019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 08/29/2012] [Accepted: 09/09/2012] [Indexed: 12/01/2022]
Abstract
Biodiversity patterns are largely determined by variation of diversification rates across clades and geographic regions. Although there are multiple reasons for this variation, it has been hypothesized that metabolic rate is the crucial driver of diversification of evolutionary lineages. According to the metabolic theory of ecology (MTE), metabolic rate - and consequently speciation - is driven mainly by body size and environmental temperature. As environmental temperature affects metabolic rate in ecto- and endotherms differently, its impact on diversification rate should also differ between the two types of organisms. Employing two independent approaches, we analysed correlates of speciation rates and, ultimately, net diversification rates for two contrasting taxa: plethodontid salamanders and carnivoran mammals. Whereas in the ectothermic plethodontids speciation rates positively correlated with environmental temperature, in the endothermic carnivorans a reverse, negative correlation was detected. These findings comply with predictions of the MTE and suggest that similar geographic patterns of biodiversity across taxa (e.g. ecto- and endotherms) might have been generated by different ecological and evolutionary processes.
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Affiliation(s)
- A Machac
- Center for Theoretical Study, Charles University and Academy of Sciences of the Czech Republic, Praha, Czech Republic.
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44
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Fisher-Reid MC, Kozak KH, Wiens JJ. How is the rate of climatic-niche evolution related to climatic-niche breadth? Evolution 2012. [PMID: 23206141 DOI: 10.1111/j.1558-5646.2012.01729.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The rate of climatic-niche evolution is important to many research areas in ecology, evolution, and conservation biology, including responses of species to global climate change, spread of invasive species, speciation, biogeography, and patterns of species richness. Previous studies have implied that clades with higher rates of climatic-niche evolution among species should have species with narrower niche breadths, but there is also evidence suggesting the opposite pattern. However, the relationships between rate and breadth have not been explicitly analyzed. Here, we examine the relationships between the rate of climatic-niche evolution and climatic-niche breadth using phylogenetic and climatic data for 250 species in the salamander family Plethodontidae, a group showing considerable variation in both rates of climatic-niche evolution and climatic-niche breadths. Contrary to some expectations, we find no general relationship between climatic-niche breadth and the rate of climatic-niche evolution. Climatic-niche breadths for some ecologically important climatic variables considered separately (temperature seasonality and annual precipitation) do show significant relationships with the rate of climatic-niche evolution, but rates are faster in clades in which species have broader (not narrower) niche breadths. In summary, our results show that narrower niche breadths are not necessarily associated with faster rates of niche evolution.
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Affiliation(s)
- M Caitlin Fisher-Reid
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York 11794-5245, USA.
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45
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Lamb T, Beamer DA. Digits lost or gained? Evidence for pedal evolution in the dwarf salamander complex (Eurycea, Plethodontidae). PLoS One 2012; 7:e37544. [PMID: 22649536 PMCID: PMC3359299 DOI: 10.1371/journal.pone.0037544] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 04/23/2012] [Indexed: 11/19/2022] Open
Abstract
Change in digit number, particularly digit loss, has occurred repeatedly over the evolutionary history of tetrapods. Although digit loss has been documented among distantly related species of salamanders, it is relatively uncommon in this amphibian order. For example, reduction from five to four toes appears to have evolved just three times in the morphologically and ecologically diverse family Plethodontidae. Here we report a molecular phylogenetic analysis for one of these four-toed lineages--the Eurycea quadridigitata complex (dwarf salamanders)--emphasizing relationships to other species in the genus. A multilocus phylogeny reveals that dwarf salamanders are paraphyletic with respect to a complex of five-toed, paedomorphic Eurycea from the Edwards Plateau in Texas. We use this phylogeny to examine evolution of digit number within the dwarf-Edwards Plateau clade, testing contrasting hypotheses of digit loss (parallelism among dwarf salamanders) versus digit gain (re-evolution in the Edwards Plateau complex). Bayes factors analysis provides statistical support for a five-toed common ancestor at the dwarf-Edwards node, favoring, slightly, the parallelism hypothesis for digit loss. More importantly, our phylogenetic results pinpoint a rare event in the pedal evolution of plethodontid salamanders.
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Affiliation(s)
- Trip Lamb
- Department of Biology, East Carolina University, Greenville, North Carolina, United States of America
| | - David A. Beamer
- Department of Biology, East Carolina University, Greenville, North Carolina, United States of America
- Department of Mathematics and Sciences, Nash Community College, Rocky Mount, North Carolina, United States of America
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46
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Concurrent speciation in the eastern woodland salamanders (Genus Plethodon): DNA sequences of the complete albumin nuclear and partial mitochondrial 12s genes. Mol Phylogenet Evol 2012; 63:278-90. [DOI: 10.1016/j.ympev.2011.12.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 12/16/2011] [Accepted: 12/19/2011] [Indexed: 11/23/2022]
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47
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Chiari Y, van der Meijden A, Mucedda M, Lourenço JM, Hochkirch A, Veith M. Phylogeography of Sardinian cave salamanders (genus Hydromantes) is mainly determined by geomorphology. PLoS One 2012; 7:e32332. [PMID: 22427830 PMCID: PMC3299655 DOI: 10.1371/journal.pone.0032332] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 01/25/2012] [Indexed: 11/24/2022] Open
Abstract
Detecting the factors that determine the interruption of gene flow between populations is key to understanding how speciation occurs. In this context, caves are an excellent system for studying processes of colonization, differentiation and speciation, since they represent discrete geographical units often with known geological histories. Here, we asked whether discontinuous calcareous areas and cave systems represent major barriers to gene flow within and among the five species of Sardinian cave salamanders (genus Hydromantes) and whether intraspecific genetic structure parallels geographic distance within and among caves. We generated mitochondrial cytochrome b gene sequences from 184 individuals representing 48 populations, and used a Bayesian phylogeographic approach to infer possible areas of cladogenesis for these species and reconstruct historical and current dispersal routes among distinct populations. Our results show deep genetic divergence within and among all Sardinian cave salamander species, which can mostly be attributed to the effects of mountains and discontinuities in major calcareous areas and cave systems acting as barriers to gene flow. While these salamander species can also occur outside caves, our results indicate that there is a very poor dispersal of these species between separate cave systems.
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Affiliation(s)
- Ylenia Chiari
- Institut des Sciences de l'Evolution, CNRS-UMR n° 5554, CC 064, Université Montpellier II, Montpellier, France.
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48
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Sun C, Shepard DB, Chong RA, López Arriaza J, Hall K, Castoe TA, Feschotte C, Pollock DD, Mueller RL. LTR retrotransposons contribute to genomic gigantism in plethodontid salamanders. Genome Biol Evol 2011; 4:168-83. [PMID: 22200636 PMCID: PMC3318908 DOI: 10.1093/gbe/evr139] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2011] [Indexed: 01/20/2023] Open
Abstract
Among vertebrates, most of the largest genomes are found within the salamanders, a clade of amphibians that includes 613 species. Salamander genome sizes range from ~14 to ~120 Gb. Because genome size is correlated with nucleus and cell sizes, as well as other traits, morphological evolution in salamanders has been profoundly affected by genomic gigantism. However, the molecular mechanisms driving genomic expansion in this clade remain largely unknown. Here, we present the first comparative analysis of transposable element (TE) content in salamanders. Using high-throughput sequencing, we generated genomic shotgun data for six species from the Plethodontidae, the largest family of salamanders. We then developed a pipeline to mine TE sequences from shotgun data in taxa with limited genomic resources, such as salamanders. Our summaries of overall TE abundance and diversity for each species demonstrate that TEs make up a substantial portion of salamander genomes, and that all of the major known types of TEs are represented in salamanders. The most abundant TE superfamilies found in the genomes of our six focal species are similar, despite substantial variation in genome size. However, our results demonstrate a major difference between salamanders and other vertebrates: salamander genomes contain much larger amounts of long terminal repeat (LTR) retrotransposons, primarily Ty3/gypsy elements. Thus, the extreme increase in genome size that occurred in salamanders was likely accompanied by a shift in TE landscape. These results suggest that increased proliferation of LTR retrotransposons was a major molecular mechanism contributing to genomic expansion in salamanders.
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Affiliation(s)
- Cheng Sun
- Department of Biology, Colorado State University
| | - Donald B. Shepard
- Department of Biology, Colorado State University
- Current address: Department of Fisheries, Wildlife and Conservation Biology; University of Minnesota
| | | | | | - Kathryn Hall
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine
| | - Todd A. Castoe
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine
| | | | - David D. Pollock
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine
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Alexander Pyron R, Wiens JJ. A large-scale phylogeny of Amphibia including over 2800 species, and a revised classification of extant frogs, salamanders, and caecilians. Mol Phylogenet Evol 2011; 61:543-83. [DOI: 10.1016/j.ympev.2011.06.012] [Citation(s) in RCA: 936] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2011] [Revised: 06/10/2011] [Accepted: 06/12/2011] [Indexed: 11/27/2022]
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50
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Kerney R. Embryonic Staging Table for a Direct-Developing Salamander, Plethodon cinereus (Plethodontidae). Anat Rec (Hoboken) 2011; 294:1796-808. [DOI: 10.1002/ar.21480] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 08/02/2011] [Indexed: 11/10/2022]
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