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Lozano D, López JM, Chinarro A, Morona R, Moreno N. A detailed 3D MRI brain atlas of the African lungfish Protopterus annectens. Sci Rep 2024; 14:7999. [PMID: 38580713 PMCID: PMC10997765 DOI: 10.1038/s41598-024-58671-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/02/2024] [Indexed: 04/07/2024] Open
Abstract
The study of the brain by magnetic resonance imaging (MRI) in evolutionary analyses is still in its incipient stage, however, it is particularly useful as it allows us to analyze detailed anatomical images and compare brains of rare or otherwise inaccessible species, evolutionarily contextualizing possible differences, while at the same time being non-invasive. A good example is the lungfishes, sarcopterygians that are the closest living relatives of tetrapods and thus have an interesting phylogenetic position in the evolutionary conquest of the terrestrial environment. In the present study, we have developed a three-dimensional representation of the brain of the lungfish Protopterus annectens together with a rostrocaudal anatomical atlas. This methodological approach provides a clear delineation of the major brain subdivisions of this model and allows to measure both brain and ventricular volumes. Our results confirm that lungfish show neuroanatomical patterns reminiscent of those of extant basal sarcopterygians, with an evaginated telencephalon, and distinctive characters like a small optic tectum. These and additional characters uncover lungfish as a remarkable model to understand the origins of tetrapod diversity, indicating that their brain may contain significant clues to the characters of the brain of ancestral tetrapods.
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Affiliation(s)
- Daniel Lozano
- Department of Cell Biology, Faculty of Biological Sciences, Complutense University, 28040, Madrid, Spain.
| | - Jesús M López
- Department of Cell Biology, Faculty of Biological Sciences, Complutense University, 28040, Madrid, Spain
| | - Adrián Chinarro
- Department of Cell Biology, Faculty of Biological Sciences, Complutense University, 28040, Madrid, Spain
| | - Ruth Morona
- Department of Cell Biology, Faculty of Biological Sciences, Complutense University, 28040, Madrid, Spain
| | - Nerea Moreno
- Department of Cell Biology, Faculty of Biological Sciences, Complutense University, 28040, Madrid, Spain
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Levy-Pereira N, Carriero MM, Yasui GS, Meira CM, de Sousa RLM, Maia AAM, Senhorini JA, Pilarski F. Effects of triploid induction on innate immunity and hematology in Astyanax altiparanae. FISH & SHELLFISH IMMUNOLOGY 2021; 116:12-18. [PMID: 33965526 DOI: 10.1016/j.fsi.2021.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 04/26/2021] [Accepted: 05/03/2021] [Indexed: 06/12/2023]
Abstract
Triploid induction is a promising biotechnique that could be used to enhance aquaculture yields in the near future. However, studies conducted with several fish species have demonstrated that the presence of an extra set of chromosomes may result in deleterious health effects. Furthermore, studies of fish immune responses still need to be conducted before these specimens can be readily commercialized. In the study presented herein, we evaluated the effects of triploid induction on hematology, erythrocyte morphometry and morphology, phagocytosis, and the expression levels of IL-1β and TGF-β using specimens of the Neotropical species, Astyanax altiparanae. In general, the cell counts of erythrocytes, leukocytes, and neutrophils in triploid fish were lower than those in diploid fish. The erythrocytes of triploid fish were larger than those found in diploid fish, but also demonstrated considerably higher frequencies of cellular and nuclear abnormalities. Although not statistically significant, triploid induction resulted in a phagocytic capacity (PC) 20% lower than that found with diploid fish. No notable differences were observed in phagocytic index (PI). Gene expression levels for the cytokine IL-1 were lower in tissues from the head kidney, liver, and spleen of triploid fish with respect to diploid fish. Gene expression levels of TGF-β were lower only in the spleen of triploids compared to diploids. In conclusion, triploid induction resulted in A. altiparanae specimens with immune impairments and potentially lower resistances to disease and low-quality environments.
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Affiliation(s)
- Nycolas Levy-Pereira
- Laboratory of Microbiology and Parasitology of Aquatic Organisms (LAPOA), Aquaculture Center (CAUNESP), São Paulo State University (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP, 14884-900, Brazil; Laboratory of Zootechnical Hygiene, Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Pirassununga, SP, Brazil. Av. Duque de Caxias Norte, 225, 13635-900, Pirassununga, São Paulo, Brazil.
| | - Mateus Maldonado Carriero
- Laboratory of Parasitology, Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Av. Duque de Caxias Norte, 225, 13635-900, Pirassununga, São Paulo, SP, Brazil
| | - George Shigueki Yasui
- Laboratory of Fish Biotechnology, National Center for Research and Conservation of Continental Fish, Chico Mendes Institute of Biodiversity Conservation, Rodovia Pref. Euberto Nemésio Pereira de Godoy, Pirassununga, SP, 13630-970, Brazil
| | - Caroline Munhoz Meira
- Laboratory of Parasitology, Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Av. Duque de Caxias Norte, 225, 13635-900, Pirassununga, São Paulo, SP, Brazil
| | - Ricardo Luiz Moro de Sousa
- Laboratory of Zootechnical Hygiene, Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Pirassununga, SP, Brazil. Av. Duque de Caxias Norte, 225, 13635-900, Pirassununga, São Paulo, Brazil
| | - Antônio Augusto Mendes Maia
- Laboratory of Parasitology, Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Av. Duque de Caxias Norte, 225, 13635-900, Pirassununga, São Paulo, SP, Brazil
| | - José Augusto Senhorini
- Laboratory of Fish Biotechnology, National Center for Research and Conservation of Continental Fish, Chico Mendes Institute of Biodiversity Conservation, Rodovia Pref. Euberto Nemésio Pereira de Godoy, Pirassununga, SP, 13630-970, Brazil
| | - Fabiana Pilarski
- Laboratory of Fish Biotechnology, National Center for Research and Conservation of Continental Fish, Chico Mendes Institute of Biodiversity Conservation, Rodovia Pref. Euberto Nemésio Pereira de Godoy, Pirassununga, SP, 13630-970, Brazil
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Nieuwenhuys R. Topological Analysis of the Brainstem of the Australian Lungfish Neoceratodus forsteri. BRAIN, BEHAVIOR AND EVOLUTION 2021; 96:242-262. [PMID: 34058732 DOI: 10.1159/000516409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 04/06/2021] [Indexed: 11/19/2022]
Abstract
This paper presents a survey of the cell masses in the brainstem of the Australian lungfish Neoceratodus forsteri, based ontransversely cut Bodian-stained serial sections, supplemented by immunohistochemical data from the recent literature. This study is intended to serve a double purpose. First it concludes and completes a series of publications on the structure of the brainstem in representative species of all groups of anamniote vertebrates. Within the framework of this comparative program the cell masses in the brainstem and their positional relations are analyzed in the light of the Herrick-Johnston concept, according to which the brainstem nuclei are arranged in four longitudinal, functional zones or columns, the boundaries of which are marked by ventricular sulci. The procedure employed in this analysis essentially involves two steps: first, the cell masses and large individual cells are projected upon the ventricular surface, and next, the ventricular surface is flattened out, that is, subjected to a one-to-one continuous topological transformation [J Comp Neurol. 1974;156:255-267]. The second purpose of the present paper is to complement our mapping of the longitudinal zonal arrangement of the cell masses in the brainstem of Neoceratoduswith a subdivision in transversely oriented neural segments. Five longitudinal rhombencephalic sulci - the sulcus medianus inferior, the sulcus intermedius ventralis, the sulcus limitans, the sulcus intermedius dorsalis and the sulcus medianus superior - and four longitudinal mesencephalic sulci - the sulcus tegmentalis medialis, the sulcus tegmentalis lateralis, the sulcus subtectalis and the sulcus lateralis mesencephali - could be distinguished. Two obliquely oriented grooves, present in the isthmic region - the sulcus isthmi dorsalis and ventralis - deviate from the overall longitudinal pattern of the other sulci. Although in Neoceratodus most neuronal perikarya are situated within a diffuse periventricular gray, 45 cell masses could be delineated. Ten of these are primary efferent or motor nuclei, eight are primary afferent or sensory centers, six are considered to be components of the reticular formation and the remaining 21 may be interpreted as "relay" nuclei. The topological analysis showed that in most of the rhombencephalon the gray matter is arranged in four longitudinal zones or areas, termed area ventralis, area intermedioventralis, area intermediodorsalis and area dorsalis. The sulcus intermedius ventralis, the sulcus limitans, and the sulcus intermedius dorsalis mark the boundaries between these morphological entities. These longitudinal zones coincide largely, but not entirely, with the functional columns of Herrick and Johnston. The most obvious incongruity is that the area intermediodorsalis contains, in addition to the viscerosensory nucleus of the solitary tract, several general somatosensory and special somatosensory centers. The isthmus region does not exhibit a clear morphological zonal pattern. The mesencephalon is divisible into a ventral, primarily motor zone and a dorsal somatosensory zone. The boundary between these zones is marked by the sulcus tegmentalis lateralis, which may be considered as an isolated rostral extremity of the sulcus limitans. The results of this study are summarized in a "classical" topological map, as well as in a "modernized" version of this map, in which neuromere borders are indicated.
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Affiliation(s)
- Rudolf Nieuwenhuys
- Department of Medical Imaging, Anatomy, Radboud University Medical Center, Nijmegen, The Netherlands.,The Netherlands Institute for Neurosciences, Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
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Lüdemann J, Fago A, Falke S, Wisniewsky M, Schneider I, Fabrizius A, Burmester T. Genetic and functional diversity of the multiple lungfish myoglobins. FEBS J 2019; 287:1598-1611. [PMID: 31610084 DOI: 10.1111/febs.15094] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/21/2019] [Accepted: 10/11/2019] [Indexed: 11/29/2022]
Abstract
It is known that the West African lungfish (Protopterus annectens) harbours multiple myoglobin (Mb) genes that are differentially expressed in various tissues and that the Mbs differ in their abilities to confer tolerance towards hypoxia. Here, we show that other lungfish species (Protopterus dolloi, Protopterus aethiopicus and Lepidosiren paradoxa) display a similar diversity of Mb genes and have orthologous Mb genes. To investigate the functional diversification of these genes, we studied the structures, O2 binding properties and nitrite reductase enzymatic activities of recombinantly expressed P. annectens Mbs (PanMbs). CD spectroscopy and small-angle X-ray scattering revealed the typical globin-fold in all investigated recombinant Mbs, indicating a conserved structure. The highest O2 affinity was measured for PanMb2 (P50 = 0.88 Torr at 20 °C), which is mainly expressed in the brain, whereas the muscle-specific PanMb1 has the lowest O2 affinity (P50 = 3.78 Torr at 20 °C), suggesting that tissue-specific O2 requirements have resulted in the emergence of distinct Mb types. Two of the mainly neuronally expressed Mbs (PanMb3 and PanMb4b) have the highest nitrite reductase rates. These data show different O2 binding and enzymatic properties of lungfish Mbs, reflecting multiple subfunctionalisation and neofunctionalisation events that occurred early in the evolution of lungfish. Some Mbs may have also taken over the functions of neuroglobin and cytoglobin, which are widely expressed in vertebrates but appear to be missing in lungfish.
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Affiliation(s)
- Julia Lüdemann
- Institute of Zoology, Department of Biology, University of Hamburg, Germany
| | - Angela Fago
- Department of Bioscience, Aarhus University, Denmark
| | - Sven Falke
- Institute for Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Germany
| | | | - Igor Schneider
- Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Andrej Fabrizius
- Institute of Zoology, Department of Biology, University of Hamburg, Germany
| | - Thorsten Burmester
- Institute of Zoology, Department of Biology, University of Hamburg, Germany
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Vallarino M, d'Amora M, Dores RM. New insights into the neuroanatomical distribution and phylogeny of opioids and POMC-derived peptides in fish. Gen Comp Endocrinol 2012; 177:338-47. [PMID: 22575795 DOI: 10.1016/j.ygcen.2012.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 04/09/2012] [Accepted: 04/13/2012] [Indexed: 01/13/2023]
Abstract
This review re-evaluates the use of immunological probes to map enkephalinergic, dynorphinergic, and endorphinergic circuits in the CNS of lobe-finned fishes, ray-finned fishes, and cartilaginous fishes in light of the characterization of proenkephalin, prodynorphin, and POMC sequences from representatives of these groups of fish over the past 20 years. The use of α-MSH specific antisera is a reliable method for detecting POMC immunopositive cell bodies and fibers. Since α-MSH and β-endorphin are co-localized in the same neurons, these studies also reveal the distribution of endorphinergic networks. Met-enkephalin specific antisera can be used to detect enkephalinergic circuits in the CNS of gnathostomes because of the ubiquitous presence of this pentapeptide in the proenkephalin sequences of gnathostomes. However, the use of leu-enkephalin specific antisera to detect enkephalinergic networks is more problematic. While this immunological probe is appropriate for analyzing enkephalinergic networks in mammals and perhaps teleosts, for the lungfishes and cartilaginous fishes this probe is more likely able to detect dynorphinergic circuits. In this regard, there is a need to re-examine dynorphinergic networks in non-mammalian gnathostomes by using species specific antisera directed against dynorphin end-products.
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Bailey SF, Kassen R. Spatial structure of ecological opportunity drives adaptation in a bacterium. Am Nat 2012; 180:270-83. [PMID: 22766936 DOI: 10.1086/666609] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abundant ecological opportunity is thought to drive adaptation and diversification. The presence of multiple opportunities leads to divergent selection, which can slow adaptation when niche-specific beneficial mutations have antagonistically pleiotropic effects. Alternately, competition for multiple opportunities can generate divergent selection, which leads to high rates of adaptive differentiation. Which outcome occurs may depend on the spatial structure of those ecological opportunities. In a mixture of resources, competition for multiple opportunities can drive divergent selection; however, if each resource is available in a spatially distinct patch, simultaneous competition for multiple opportunities cannot occur. We report the effects of the extent and spatial structure of ecological opportunity on the evolutionary dynamics of populations of Pseudomonas fluorescens over 1,000 generations. We varied the extent of ecological opportunity by varying the number of sugar resources (mannose, glucose, and xylose), and we varied spatial structure by providing resources in either mixtures or spatially distinct patches. We saw that a particularly novel resource (xylose) drove the rate of adaptation when provided in a mixture but had no effect on diversity. Instead, we saw the evolution of a single adaptive strategy that differed with respect to phenotype and degree of specialization, depending on both the extent and the spatial structure of ecological opportunity.
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Affiliation(s)
- Susan F Bailey
- Department of Biology and Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ontario K1N 6N5, Canada.
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Abstract
Mutation rates vary significantly within the genome and across species. Recent studies revealed a long suspected replication-timing effect on mutation rate, but the mechanisms that regulate the increase in mutation rate as the genome is replicated remain unclear. Evidence is emerging, however, that DNA repair systems, in general, are less efficient in late replicating heterochromatic regions compared to early replicating euchromatic regions of the genome. At the same time, mutation rates in both vertebrates and invertebrates have been shown to vary with generation time (GT). GT is correlated with genome size, which suggests a possible nucleotypic effect on species-specific mutation rates. These and other observations all converge on a role for DNA replication checkpoints in modulating generation times and mutation rates during the DNA synthetic phase (S phase) of the cell cycle. The following will examine the potential role of the intra-S checkpoint in regulating cell cycle times (GT) and mutation rates in eukaryotes. This article was published online on August 5, 2011. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected October 4, 2011.
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Affiliation(s)
- John Herrick
- Department of Physics, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada.
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Dores RM, Majeed Q, Komorowski L. Observations on the radiation of lobe-finned fishes, ray-finned fishes, and cartilaginous fishes: phylogeny of the opioid/orphanin gene family and the 2R hypothesis. Gen Comp Endocrinol 2011; 170:253-64. [PMID: 20937278 DOI: 10.1016/j.ygcen.2010.09.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 09/28/2010] [Accepted: 09/30/2010] [Indexed: 11/17/2022]
Abstract
At the close of the Devonian Period the rapid decline in the diversity of the lobe-finned fishes was countered by the emergence and diversification of the ray-finned fishes and the cartilaginous fishes that now dominate marine and freshwater ecosystems. All of these jawed vertebrates were derived from the ancestral gnathostomes; a chordate lineage that had experienced two genome duplication events during the evolution of the phylum. This review analyzes trends in the phylogeny of the opioid/orphanin gene family (four prohormone/neuropeptide precursor-coding genes) in the major classes of gnathostomes that survived the extinction events at the close of the Devonian Period and focuses on some features of this gene family that appear to set the cartilaginous fishes (class Chondrichthyes) apart from class Sarcopterygii (lobe-finned fishes and tetrapods) and class Actinopterygii (the ray-finned fishes).
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Affiliation(s)
- Robert M Dores
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA.
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Immunohistochemical localization of calbindin D28k and calretinin in the retina of two lungfishes, Protopterus dolloi and Neoceratodus forsteri: Colocalization with choline acetyltransferase and tyrosine hydroxylase. Brain Res 2011; 1368:28-43. [DOI: 10.1016/j.brainres.2010.10.098] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 10/26/2010] [Accepted: 10/26/2010] [Indexed: 01/25/2023]
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Morona R, Northcutt RG, González A. Immunohistochemical localization of calbindin-D28k and calretinin in the spinal cord of lungfishes. BRAIN, BEHAVIOR AND EVOLUTION 2010; 76:198-210. [PMID: 21051876 DOI: 10.1159/000321326] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 09/06/2010] [Indexed: 02/03/2023]
Abstract
A common pattern of distribution of neurons and fibers containing the calcium-binding proteins calbindin-D28k (CB) and calretinin (CR) in the spinal cord of terrestrial vertebrates has been recently demonstrated. Lungfishes are considered the closest living relatives of tetrapods, but practically no experimental data exist on the organization of their spinal cord. By means of immunohistochemical techniques, the localization of CB and CR was investigated in the spinal cord of the African (Protopterus dolloi) and Australian (Neoceratodus forsteri) lungfishes. Abundant cell bodies and fibers immunoreactive for either CB or CR were widely distributed throughout the spinal cord. A large population of immunoreactive cells was found in the dorsal column of the gray matter in both species, and abundant cells were distributed in the lateral and ventral columns. Ventrolateral motoneurons and multipolar cells were only intensely CB and CR immunoreactive in Neoceratodus. For the most part, separate cell populations contained either CB or CR, but a small subset of dorsally located neurons contained both in the two lungfishes. Colocalization was found in motoneurons and in ventrolaterally located cells only in Neoceratodus. Fiber labeling showed a predominance of CR-containing axons in the lateral and ventral funiculi of presumed supraspinal origin. These results show that lung-fishes and tetrapods have many features in common, suggesting that primitive anatomical, and likely functional, organization of the spinal cord of tetrapods is present in lungfishes.
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Affiliation(s)
- Ruth Morona
- Department of Cell Biology, University Complutense, Madrid, Spain
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Gustafsson OSE, Ekström P, Kröger RHH. A fibrous membrane suspends the multifocal lens in the eyes of lampreys and African lungfishes. J Morphol 2010; 271:980-9. [PMID: 20623650 DOI: 10.1002/jmor.10849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The sharpness and thus information content of the retinal image in the eye depends on the optical quality of the lens and its accurate positioning in the eye. Multifocal lenses create well-focused color images and are present in the eyes of all vertebrate groups studied to date (mammals, reptiles including birds, amphibians, and ray-finned fishes) and occur even in lampreys, i.e., the most basal vertebrates with well-developed eyes. Results from photoretinoscopy obtained in this study indicate that the Dipnoi (lungfishes), i.e., the closest piscine relatives to tetrapods, also possess multifocal lenses. Suspension of the lens is complex and sophisticated in teleosts (bony fishes) and tetrapods. We studied lens suspension using light and electron microscopy in one species of lamprey (Lampetra fluviatilis) and two species of African lungfish (Protopterus aethiopicus aethiopicus and Protopterus annectens annectens). A fibrous and highly transparent membrane suspends the lens in both of these phylogenetically widely separated vertebrate groups. The membrane attaches to the lens approximately along the lens equator, from where it extends to the ora retinalis. The material forming the membrane is similar in ultrastructure to microfibrils in the zonule fibers of tetrapods. The membrane, possibly in conjunction with the cornea, iris, and vitreous body, seems suitable for keeping the lens in the correct position for well-focused imaging. Suspension of the lens by a multitude of zonule fibers in tetrapods may have evolved from a suspensory membrane similar to that in extant African lungfishes, a structure that seems to have appeared first in the lamprey-like ancestors of allextant vertebrates.
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Affiliation(s)
- Ola S E Gustafsson
- Department of Biology, Lund University, Zoology Building, Helgonavägen 3, 223 62 Lund, Sweden.
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González A, Morona R, López JM, Moreno N, Northcutt RG. Lungfishes, like tetrapods, possess a vomeronasal system. Front Neuroanat 2010; 4. [PMID: 20941371 PMCID: PMC2951178 DOI: 10.3389/fnana.2010.00130] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 07/31/2010] [Indexed: 01/09/2023] Open
Abstract
The vomeronasal system (VNS) is an accessory olfactory system that in tetrapod vertebrates is composed of specific receptor neurons in the nasal organ and a set of centers in the forebrain that receive and relay the information consecutively towards the hypothalamus. Thus, only in tetrapods the VNS comprises a discrete vomeronasal (Jacobson's) organ, which contains receptor cells that are morphologically distinct from those of the olfactory epithelium and use different transduction mechanisms. The axons of the vomeronasal receptors in tetrapods project to the accessory olfactory bulb (AOB) in the rostral telencephalon. Secondary vomeronasal connections exist through the medial amygdala to the hypothalamus. Currently, the lungfishes are considered the closest living relatives of tetrapods. Here we show that the African lungfish, Protopterus dolloi, has epithelial crypts at the base of the lamellae of the olfactory epithelium that express markers of the vomeronasal receptors in tetrapods. The projections of these crypts allow us to identify an AOB on the lateral margin of the main olfactory bulb. The projections of this AOB reach a region that is topologically, hodologically, and immunohistochemically identical to the medial amygdala and could represent its homolog. Neurons of this putative medial amygdala were demonstrated to project to the lateral hypothalamus, as they do in tetrapods. All these features that lungfishes share with tetrapods indicate that lungfishes have the complete set of brain centers and connections involved in processing vomeronasal information and that these features were already present in the last common ancestor of lungfishes and tetrapods.
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Affiliation(s)
- Agustín González
- Department of Cell Biology, Faculty of Biology, University Complutense of Madrid Madrid, Spain
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Venkatasamy R, McKenzie A, Page CP, Walker MJ, Spina D. Use of within-group designs to test anti-tussive drugs in conscious guinea-pigs. J Pharmacol Toxicol Methods 2010; 61:157-62. [PMID: 20193769 DOI: 10.1016/j.vascn.2010.02.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 12/13/2009] [Accepted: 02/18/2010] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Cough is a common medical problem for which there are few effective drug treatments. A limited understanding of the mechanisms of induction and maintenance of cough and a paucity of suitable animal models frustrate drug discovery efforts to find novel anti-tussives. As in humans, guinea-pigs evoke a cough reflex upon exposure to tussive agents such as citric acid and capsaicin; both of which have been widely used to assess novel anti-tussive drugs. However, the potential for using within-group designs in drug development has received little attention and such designs may offer a way of assisting the drug discovery effort in the area of cough as well as other areas. METHODS Cough can be monitored in conscious guinea-pigs by placing animals in a Perspex chamber, in which air is continually exchanged by use of negative pressure and drug delivery of aerosols to the chamber can be accurately timed. Cough in response to a tussive agent (e.g. 0.2-0.4M citric acid; 10-30 microM capsaicin) is detected by the simultaneous microphonic recording of audible signals characteristic of the cough response as well as by positive pressure changes in the chamber generated by a cough dependent rapid expiration of air from the lungs. Both the sound and pressure signals are recorded using an online analyzer, whilst the number of coughs can be analyzed off-line. The number of coughs over a 15 min period is used to quantitate tussive events. RESULTS Reproducible cough can be detected in animals using cross-over designs that lend themselves to drug studies. Both the time and concentration dependence of anti-tussive drug action can be evaluated in the same animal. Furthermore, the effect of different anti-tussive drugs can be evaluated thereby reducing between group error and thereby improving the sensitivity of the test. DISCUSSION Repeated measures design improves the precision with which to evaluate anti-tussive drugs in preclinical models and could be used to make the drug discovery process more efficient.
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Affiliation(s)
- R Venkatasamy
- Sackler Institute of Pulmonary Pharmacology, Pharmaceutical Science Division, School of Biomedical and Health Science, Kings College London, London SE1 1UL, United Kingdom
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Aigoin DA, Devos N, Huttunen S, Ignatov MS, Gonzalez-Mancebo JM, Vanderpoorten A. AND IF ENGLER WAS NOT COMPLETELY WRONG? EVIDENCE FOR MULTIPLE EVOLUTIONARY ORIGINS IN THE MOSS FLORA OF MACARONESIA. Evolution 2009; 63:3248-57. [DOI: 10.1111/j.1558-5646.2009.00787.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
To analyze myelin structure and the composition of myelinated tissue in the African lungfish(Protopterus dolloi), we used a combination of ultrastructural and biochemical techniques. Electron microscopy showed typical multilamellar myelin: CNS sheaths abutted one another, and PNS sheaths were separated by endoneurial collagen. The radial component, prominent in CNS myelin of higher vertebrates, was suggested by the pattern of staining but was poorly organized. The lipid and myelin protein compositions of lungfish tissues more closely resembled those of teleost than those of higher vertebrates (frog, mouse). Of particular note, for example, lungfish glycolipids lacked hydroxy fatty acids. Native myelin periodicities from unfixed nerves were in the range of those for higher vertebrates rather than for teleost fish. Lungfish PNS myelin had wider inter-membrane spaces compared with other vertebrates, and lungfish CNS myelin had spaces that were closer in value to those in mammalian than to amphibian or teleost myelins. The membrane lipid bilayer was narrower in lungfish PNS myelin compared to other vertebrates, whereas in the CNS myelin the bilayer was in the typical range. Lungfish PNS myelin showed typical compaction and swelling responses to incubation in acidic or alkaline hypotonic saline. The CNS myelin, by contrast, did not compact in acidic saline but did swell in the alkaline solution. This lability was more similar to that for the higher vertebrates than for teleost.
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17
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Chung KF, Widdicombe J. Peripheral mechanisms II: the pharmacology of peripherally active antitussive drugs. Handb Exp Pharmacol 2009; 187:155-86. [PMID: 18825340 PMCID: PMC7122788 DOI: 10.1007/978-3-540-79842-2_8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cough is an indispensable defensive reflex. Although generally beneficial, it is also a common symptom of diseases such as asthma, chronic obstructive pulmonary disease, upper respiratory tract infections, idiopathic pulmonary fibrosis and lung cancer. Cough remains a major unmet medical need and although the centrally acting opioids have remained the antitussive of choice for decades, they have many unwanted side effects. However, new research into the behaviour of airway sensory nerves has provided greater insight into the mechanisms of cough and new avenues for the discovery of novel non-opioid antitussive drugs. In this review, the pathophysiological mechanisms of cough and the development of novel antitussive drugs are reviewed.
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Affiliation(s)
- Kian Fan Chung
- National Heart & Lung Institute, Imperial College, Dovehouse Street, London, SW3 6LY UK
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18
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Bojnik E, Magyar A, Tóth G, Bajusz S, Borsodi A, Benyhe S. Binding studies of novel, non-mammalian enkephalins, structures predicted from frog and lungfish brain cDNA sequences. Neuroscience 2008; 158:867-74. [PMID: 18977279 DOI: 10.1016/j.neuroscience.2008.09.056] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 08/30/2008] [Accepted: 10/27/2008] [Indexed: 01/30/2023]
Abstract
Leu- and Met-enkephalin were the first endogenous opioid peptides identified in different mammalian species including the human. Comparative biochemical and bioinformatic evidence indicates that enkephalins are not limited to mammals. Various prodynorphin (PDYN) sequences in lower vertebrates revealed the presence of other enkephalin fingerprints in these precursor polypeptides. Among the novel enkephalins Ile-enkephalin (Tyr-Gly-Gly-Phe-Ile) was primarily observed in the African clawed frog (Xenopus laevis) PDYNs, while the structure of Phe-enkephalin (Tyr-Gly-Gly-Phe-Phe) was predicted by analyzing brain cDNA sequences encoding a PDYN of the African lungfish (Protopterus annectens). Ile-enkephalin can also be found in the PDYNs of four other fish species including the eel, bichir, zebrafish and tilapia, but no further occurrence for the Phe-enkephalin motif is available as yet. Based on sequencing data, the biological relevance of Phe- and Ile-enkephalin is suggested, because both of them can arise by regular posttranslational enzymatic processing of the respective neuropeptide precursors. In various receptor binding assays performed on rat brain membrane preparations both of the new peptides turned out to be moderate affinity opioids with a weak preference for the delta-opioid receptor (DOP) sites. Phe-enkephalin of the lungfish displayed rather unexpectedly low affinities toward the mu-opioid receptor (MOP) and DOP, while exhibiting moderate affinity toward the kappa-opioid receptor (KOP). In receptor-mediated G-protein activation assays measured by the stimulation of [(35)S]GTPgammaS binding, Met-enkephalin produced the highest stimulation followed by Leu-enkephalin, Ile-enkephalin and Phe-enkephalin, whereas the least efficacious among these endogenous peptides was still more effective than the prototype opiate agonist morphine in these functional tests.
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Affiliation(s)
- E Bojnik
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvari krt 62, 6726 Szeged, Hungary.
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19
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Abstract
This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, United States.
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