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Derek E. G. Briggs - One of the best experts on this subject based on the ideXlab platform.
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the winneshiek biota exceptionally well preserved fossils in a middle ordovician impact crater
2018Co-Authors: Derek E. G. Briggs, Robert Mckay, Brian J WitzkeAbstract:The Winneshiek Shale (Middle Ordovician, Darriwilian) was deposited in a meteorite crater, the Decorah impact structure, in NE Iowa. This crater is 5.6 km in diameter and penetrates Cambrian and Ordovician cratonic strata. It was probably situated close to land in an embayment connected to the epicontinental sea; typical shelly marine taxa are absent. The Konservat-Lagerstatte within the Winneshiek Shale is important because it represents an interval when exceptional preservation is rare. The biota includes the earliest eurypterid, a giant form, as well as a new basal chelicerate and the earliest ceratiocarid phyllocarid. Conodonts, some of giant size, occur as bedding plane assemblages. Bromalites and rarer elements, including a linguloid brachiopod and a probable Jawless Fish, are also present. Similar fossils occur in the coeval Ames impact structure in Oklahoma, demonstrating that meteorite craters represent a novel and under-recognized setting for Konservat-Lagerstatten.
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taphonomy and biological affinity of three dimensionally phosphatized bromalites from the middle ordovician winneshiek lagerstatte northeastern iowa usa
2018Co-Authors: Andrew D Hawkins, Brian J Witzke, A D Muscente, Robert Mckay, Derek E. G. Briggs, Shuhai XiaoAbstract:Abstract The Winneshiek Lagerstatte occurs within an Ordovician meteorite impact structure beneath part of the city of Decorah, Iowa. The Lagerstatte has yielded an atypical marine fauna including phyllocarid crustaceans, eurypterids, conodonts, linguloid brachiopods, and Jawless Fish. Associated with these taxa are vermiform fossils: elongate, morphologically variable, and often three-dimensionally preserved bromalites of uncertain organisms. The preservational state of these bromalites is significantly different from that of other components of the Winneshiek biota. Here we present a compositional and microstructural analysis of the vermiform fossils in order to elucidate their taphonomy and biological affinities. The majority of studied specimens are preserved three-dimensionally and composed of calcium phosphate, while a minority are preserved as carbonaceous compressions. Winneshiek bromalites exhibit important similarities to examples documented from both older and younger sediments. They provide in...
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taphonomy and biological affinity of three dimensionally phosphatized bromalites from the middle ordovician winneshiek lagerstatte northeastern iowa usa
2018Co-Authors: Andrew D Hawkins, Brian J Witzke, A D Muscente, Robert Mckay, Derek E. G. Briggs, Shuhai XiaoAbstract:The Winneshiek Lagerstatte occurs within an Ordovician meteorite impact structure beneath part of the city of Decorah, Iowa. The Lagerstatte has yielded an atypical marine fauna including phyllocarid crustaceans, eurypterids, conodonts, linguloid brachiopods, and Jawless Fish. Associated with these taxa are vermiform fossils: elongate, morphologically variable, and often three-dimensionally preserved bromalites of uncertain organisms. The preservational state of these bromalites is significantly different from that of other components of the Winneshiek biota. Here we present a compositional and microstructural analysis of the vermiform fossils in order to elucidate their taphonomy and biological affinities. The majority of studied specimens are preserved three-dimensionally and composed of calcium phosphate, while a minority are preserved as carbonaceous compressions. Winneshiek bromalites exhibit important similarities to examples documented from both older and younger sediments. They provide independent evidence of predation in the Winneshiek assemblage during the Great Ordovician Biodiversification Event.
Edward C Holmes - One of the best experts on this subject based on the ideXlab platform.
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slippery when wet cross species transmission of divergent coronaviruses in bony and Jawless Fish and the evolutionary history of the coronaviridae
2021Co-Authors: Allison K Miller, Jonathon C O Mifsud, Vincenzo A Costa, Rebecca M Grimwood, Jane Kitson, Cindy F Baker, Cara L Brosnahan, Anjali Pande, Edward C HolmesAbstract:Abstract The Nidovirales comprise a genetically diverse group of positive-sense single-stranded RNA virus families that infect a range of invertebrate and vertebrate hosts. Recent metagenomic studies have identified nido-like virus sequences, particularly those related to the Coronaviridae, in a range of aquatic hosts including Fish, amphibians and reptiles. We sought to identify additional members of the Coronaviridae in both bony and Jawless Fish through a combination of total RNA sequencing (meta-transcriptomics) and data mining of published RNA sequencing data, and from this reveal more of the long-term patterns and processes of coronavirus evolution. Accordingly, we identified a number of divergent viruses that fell within the Letovirinae subfamily of the Coronaviridae, including those in a Jawless Fish – the pouched lamprey. By mining Fish transcriptome data we identified additional virus transcripts matching these viruses in bony Fish from both marine and freshwater environments. These new viruses retained sequence conservation in the RNA-dependant RNA polymerase across the Coronaviridae, but formed a distinct and diverse phylogenetic group. Although there are broad-scale topological similarities between the phylogenies of the major groups of coronaviruses and their vertebrate hosts, the evolutionary relationships of viruses within the Letovirinae does not mirror that of their hosts. For example, the coronavirus found in the pouched lamprey fell within the phylogenetic diversity of bony Fish letoviruses, indicative of past host switching events. Hence, despite possessing a phylogenetic history that likely spans the entire history of the vertebrates, coronavirus evolution has been characterised by relatively frequent cross-species transmission, particularly in hosts that reside in aquatic habitats.
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the evolutionary history of vertebrate rna viruses
2018Co-Authors: Xiao Chen, Edward C Holmes, John-sebastian Eden, Junhua Tian, Liangjun Chen, Kun Li, Wen Wang, Jinjin ShenAbstract:Our understanding of the diversity and evolution of vertebrate RNA viruses is largely limited to those found in mammalian and avian hosts and associated with overt disease. Here, using a large-scale meta-transcriptomic approach, we discover 214 vertebrate-associated viruses in reptiles, amphibians, lungFish, ray-finned Fish, cartilaginous Fish and Jawless Fish. The newly discovered viruses appear in every family or genus of RNA virus associated with vertebrate infection, including those containing human pathogens such as influenza virus, the Arenaviridae and Filoviridae families, and have branching orders that broadly reflected the phylogenetic history of their hosts. We establish a long evolutionary history for most groups of vertebrate RNA virus, and support this by evaluating evolutionary timescales using dated orthologous endogenous virus elements. We also identify new vertebrate-specific RNA viruses and genome architectures, and re-evaluate the evolution of vector-borne RNA viruses. In summary, this study reveals diverse virus–host associations across the entire evolutionary history of the vertebrates.
Brian J Witzke - One of the best experts on this subject based on the ideXlab platform.
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the winneshiek biota exceptionally well preserved fossils in a middle ordovician impact crater
2018Co-Authors: Derek E. G. Briggs, Robert Mckay, Brian J WitzkeAbstract:The Winneshiek Shale (Middle Ordovician, Darriwilian) was deposited in a meteorite crater, the Decorah impact structure, in NE Iowa. This crater is 5.6 km in diameter and penetrates Cambrian and Ordovician cratonic strata. It was probably situated close to land in an embayment connected to the epicontinental sea; typical shelly marine taxa are absent. The Konservat-Lagerstatte within the Winneshiek Shale is important because it represents an interval when exceptional preservation is rare. The biota includes the earliest eurypterid, a giant form, as well as a new basal chelicerate and the earliest ceratiocarid phyllocarid. Conodonts, some of giant size, occur as bedding plane assemblages. Bromalites and rarer elements, including a linguloid brachiopod and a probable Jawless Fish, are also present. Similar fossils occur in the coeval Ames impact structure in Oklahoma, demonstrating that meteorite craters represent a novel and under-recognized setting for Konservat-Lagerstatten.
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taphonomy and biological affinity of three dimensionally phosphatized bromalites from the middle ordovician winneshiek lagerstatte northeastern iowa usa
2018Co-Authors: Andrew D Hawkins, Brian J Witzke, A D Muscente, Robert Mckay, Derek E. G. Briggs, Shuhai XiaoAbstract:Abstract The Winneshiek Lagerstatte occurs within an Ordovician meteorite impact structure beneath part of the city of Decorah, Iowa. The Lagerstatte has yielded an atypical marine fauna including phyllocarid crustaceans, eurypterids, conodonts, linguloid brachiopods, and Jawless Fish. Associated with these taxa are vermiform fossils: elongate, morphologically variable, and often three-dimensionally preserved bromalites of uncertain organisms. The preservational state of these bromalites is significantly different from that of other components of the Winneshiek biota. Here we present a compositional and microstructural analysis of the vermiform fossils in order to elucidate their taphonomy and biological affinities. The majority of studied specimens are preserved three-dimensionally and composed of calcium phosphate, while a minority are preserved as carbonaceous compressions. Winneshiek bromalites exhibit important similarities to examples documented from both older and younger sediments. They provide in...
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taphonomy and biological affinity of three dimensionally phosphatized bromalites from the middle ordovician winneshiek lagerstatte northeastern iowa usa
2018Co-Authors: Andrew D Hawkins, Brian J Witzke, A D Muscente, Robert Mckay, Derek E. G. Briggs, Shuhai XiaoAbstract:The Winneshiek Lagerstatte occurs within an Ordovician meteorite impact structure beneath part of the city of Decorah, Iowa. The Lagerstatte has yielded an atypical marine fauna including phyllocarid crustaceans, eurypterids, conodonts, linguloid brachiopods, and Jawless Fish. Associated with these taxa are vermiform fossils: elongate, morphologically variable, and often three-dimensionally preserved bromalites of uncertain organisms. The preservational state of these bromalites is significantly different from that of other components of the Winneshiek biota. Here we present a compositional and microstructural analysis of the vermiform fossils in order to elucidate their taphonomy and biological affinities. The majority of studied specimens are preserved three-dimensionally and composed of calcium phosphate, while a minority are preserved as carbonaceous compressions. Winneshiek bromalites exhibit important similarities to examples documented from both older and younger sediments. They provide independent evidence of predation in the Winneshiek assemblage during the Great Ordovician Biodiversification Event.
Masanori Kasahara - One of the best experts on this subject based on the ideXlab platform.
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origin and evolution of the adaptive immune system genetic events and selective pressures
2010Co-Authors: Martin F. Flajnik, Masanori KasaharaAbstract:The adaptive immune system (AIS) in mammals, which is centred on lymphocytes bearing antigen receptors that are generated by somatic recombination, arose approximately 500 million years ago in jawed Fish. This intricate defence system consists of many molecules, mechanisms and tissues that are not present in Jawless vertebrates. Two macroevolutionary events are believed to have contributed to the genesis of the AIS: the emergence of the recombination-activating gene (RAG) transposon, and two rounds of whole-genome duplication. It has recently been discovered that a non-RAG-based AIS with similarities to the jawed vertebrate AIS — including two lymphoid cell lineages — arose in Jawless Fish by convergent evolution. We offer insights into the latest advances in this field and speculate on the selective pressures that led to the emergence and maintenance of the AIS.
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structural diversity of the hagFish variable lymphocyte receptors
2006Co-Authors: Secheol Oh, Jun Kasamatsu, Beom Seok Park, Masanori KasaharaAbstract:Abstract Variable lymphocyte receptors (VLRs) are recently discovered leucine-rich repeat (LRR) family proteins that mediate adaptive immune responses in Jawless Fish. Phylogenetically it is the oldest adaptive immune receptor and the first one with a non-immunoglobulin fold. We present the crystal structures of one VLR-A and two VLR-B clones from the inshore hagFish. The hagFish VLRs have the characteristic horseshoe-shaped structure of LRR family proteins. The backbone structures of their LRR modules are highly homologous, and the sequence variation is concentrated on the concave surface of the protein. The conservation of key residues suggests that our structures are likely to represent the LRR structures of the entire repertoire of Jawless Fish VLRs. The analysis of sequence variability, prediction of protein interaction surfaces, amino acid composition analysis, and structural comparison with other LRR proteins suggest that the hypervariable concave surface is the most probable antigen binding site of the VLR.
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variable lymphocyte receptors in hagFish
2005Co-Authors: Zeev Pancer, Masanori Kasahara, Takashi Suzuki, Jun Kasamatsu, Chris T Amemiya, Nil Ratan Saha, Max D CooperAbstract:A previously uncharacterized type of variable lymphocyte receptors (VLR) was identified recently in the Sea lamprey. This Jawless vertebrate generates an extensive VLR repertoire through differential insertion of neighboring diverse leucine-rich repeat (LRR) cassettes into an incomplete germ-line VLR gene. We report here VLR homologs from two additional lamprey species and the presence of two types of VLR genes in hagFish, the only other order of contemporary Jawless vertebrates. As in the Sea lamprey, the incomplete hagFish germ-line VLR-A and -B genes are modified in lymphocyte-like cells to generate highly diverse repertoires of VLR-A and -B proteins via a presently undetermined mechanism. This Jawless-Fish mode of VLR diversification starkly contrasts with the rearrangement of Ig V(D)J gene segments used by all jawed vertebrates to produce diverse repertoires of T and B lymphocyte antigen receptors. The development of two very different strategies for receptor diversification at the dawn of vertebrate evolution ≈500 million years ago attests to the fitness value of a lymphocyte-based system of anticipatory immunity.
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Construction of a bacterial artificial chromosome library from the inshore hagFish, Eptatretus burgeri: A resource for the analysis of the agnathan genome.
2004Co-Authors: Takashi Suzuki, Tatsuya Ota, Asao Fujiyama, Masanori KasaharaAbstract:The Jawless Fish occupy an important phylogenetic position for understanding the evolution of body plans, the origin of adaptive immunity and genome evolution in chordates. We describe here the construction of a large-insert bacterial artificial chromosome (BAC) library from the inshore hagFish, Eptatretus burgeri. The BAC library contains 93,978 clones with an average insert size of 100 kb and is estimated to represent threefold genome-equivalent coverage. The library was organized in three-dimensional pools to facilitate screening by PCR. We have screened this library by PCR and isolated several BAC clones; the average number of positive clones was compatible with the estimated genome coverage of the library. This BAC library, constructed for the first time from the Jawless Fish, should serve as a useful resource for the scientific community.
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the leukocyte common antigen cd45 of the pacific hagFish eptatretus stoutii implications for the primordial function of cd45
2002Co-Authors: Taeko Nagata, Martin F. Flajnik, Takashi Suzuki, Yuko Ohta, Masanori KasaharaAbstract:CD45, originally known as the leukocyte common antigen, is a prototypical transmembrane protein tyrosine phosphatase that plays a critical role in signal transduction through T-cell and B-cell receptors, as well as in T-cell and B-cell development. In the present study, we show that the Pacific hagFish, widely believed to lack the adaptive immune system, has CD45. The presence of CD45 in Jawless Fish is consistent with the recent discovery that CD45 also plays a crucial role in innate immunity via the regulation of signaling through type I and type II cytokine receptors. It is likely that CD45 was recruited to activate lymphocytes through antigen receptors encoded by rearranging genes in jawed vertebrates.
Barbara S Zielinski - One of the best experts on this subject based on the ideXlab platform.
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multi glomerular projection of single olfactory receptor neurons is conserved among amphibians
2020Co-Authors: Lukas Weiss, Barbara S Zielinski, Lucas D Jungblut, Andrea G Pozzi, Lauren A Oconnell, Thomas Hassenklover, Ivan ManziniAbstract:Individual receptor neurons in the peripheral olfactory organ extend long axons into the olfactory bulb forming synapses with projection neurons in spherical neuropil regions, called glomeruli. Generally, odor map formation and odor processing in all vertebrates is based on the assumption that receptor neuron axons exclusively connect to a single glomerulus without any axonal branching. We comparatively tested this hypothesis in multiple Fish and amphibian species (both sexes) by applying sparse cell electroporation to trace single olfactory receptor neuron axons. Sea lamprey (Jawless Fish) and zebraFish (bony Fish) support the unbranched axon concept, with 94% of axons terminating in single glomeruli. Contrastingly, axonal projections of the axolotl (salamander) branch extensively before entering up to six distinct glomeruli. Receptor neuron axons labeled in frog species (Pipidae, Bufonidae, Hylidae, and Dendrobatidae) predominantly bifurcate before entering a glomerulus and 59 and 50% connect to multiple glomeruli in larval and postmetamorphotic animals, respectively. Independent of developmental stage, lifestyle, and adaptations to specific habitats, it seems to be a common feature of amphibian olfactory receptor neuron axons to frequently bifurcate and connect to multiple glomeruli. Our study challenges the unbranched axon concept as a universal vertebrate feature and it is conceivable that also later diverging vertebrates deviate from it. We propose that this unusual wiring logic evolved around the divergence of the terrestrial tetrapod lineage from its aquatic ancestors and could be the basis of an alternative way of odor processing.
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multi glomerular projection of single olfactory receptor neurons is conserved among amphibians
2019Co-Authors: Lukas Weiss, Barbara S Zielinski, Lucas D Jungblut, Andrea G Pozzi, Lauren A Oconnell, Thomas Hassenklover, Ivan ManziniAbstract:Individual receptor neurons in the peripheral olfactory organ extend long axons into the olfactory bulb forming synapses with projection neurons in spherical neuropil regions, called glomeruli. Generally, odor map formation and odor processing in all vertebrates is based on the assumption that receptor neuron axons exclusively connect to a single glomerulus without any axonal branching. We comparatively tested this hypothesis in multiple Fish and amphibian species by applying sparse cell electroporation to trace single olfactory receptor neuron axons. Sea lamprey (Jawless Fish) and zebraFish (bony Fish) support the unbranched axon concept, with 94% of axons terminating in single glomeruli. Contrastingly, axonal projections of the axolotl (salamander) branch extensively before entering up to six distinct glomeruli. Receptor neuron axons labeled in frog species (Pipidae, Bufonidae, Hylidae and Dendrobatidae) predominantly bifurcate before entering a glomerulus and 59% and 50% connect to multiple glomeruli in larval and post-metamorphotic animals, respectively. Independent of developmental stage, lifestyle and adaptations to specific habitats, it seems to be a common feature of amphibian olfactory receptor neuron axons to frequently bifurcate and connect to multiple glomeruli. Our study challenges the unbranched axon concept as a universal vertebrate feature and it is conceivable that also later diverging vertebrates deviate from it. We propose that this unusual wiring logic evolved around the divergence of the terrestrial tetrapod lineage from its aquatic ancestors and could be the basis of an alternative way of odor processing.
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Olfactory sensory neurons in the sea lamprey display polymorphisms.
2007Co-Authors: Alyson J. Laframboise, Xiang Ren, Steven Chang, Réjean Dubuc, Barbara S ZielinskiAbstract:The sea lamprey (Petromyzon marinus) is an ancient Jawless Fish phyletically removed from modern (teleost) Fishes. It is an excellent organism in the study of olfaction due to its accessible olfactory pathway, which is susceptible to manipulation, and its important location in the evolution of vertebrates. There are many similarities in the olfactory systems of all Fishes, and they also share characteristics with the olfactory system of mammals. Teleost Fishes lack the distinctive vomeronasal organ of mammals; rather all odours are processed initially by olfactory sensory neurons (OSNs) of three morphotypes within the olfactory epithelium. We sought to identify olfactory sensory neuron polymorphisms in the sea lamprey. Using retrograde tracing with dyes injected into the olfactory bulb, we identified three morphotypes which are highly similar to those found in teleosts. This study provides the first evidence of morphotypes in the sea lamprey peripheral olfactory organ, and indicates that olfactory sensory neuron polymorphism may be a trait highly conserved throughout vertebrate evolution.