scholarly journals New data on dinophilid neurogenesis: a variation of a common pattern

2020 ◽  
Author(s):  
Elizaveta Fofanova ◽  
Tatiana Mayorova ◽  
Elena Voronezhskaya
Keyword(s):  
Nervous System ◽  
Developmental Stages ◽  
System Development ◽  
Nervous System Development ◽  
Model Systems ◽  
Common Pattern ◽  
Acetylated Tubulin ◽  
Reported Study ◽  
Pioneer Neurons ◽  
Tubulin Antibodies

Abstract BackgroundThe structure and development of the nervous system in Lophotrochozoa species is of the most important questions for comparative neurobiology. During the last decade the number of comprehensive studies on the development of serotonergic and FMRFamidergic systems has been skyrocketing. However, the detailed research of the earliest events of Polychaeta neurogenesis is still sparce. Polychaeta is a huge taxon within Lophotrochozoa. Its representatives are widely used as model systems in developmental and physiological investigations. Dinophilidae is a unique Polychaeta group. Its representatives combine morphological traits of different lophotrochozoan taxa. Moreover, adult dinophilids demonstrate morphological similarity to a trochophore larva. This similarity may be associated with either archaic origin of this group or neoteny. The main goal of our study is to provide a detailed description of the earliest events in Dinophilus neurogenesis. These data might improve our understanding of Polychaeta development and evolution.ResultsWe have studied the earliest events in nervous system development in two relative species D. gyrociliatus and D. taeniatus using immunochemical labelling of serotonin, FMRF-amide related peptides, and acetylated tubulin. We used external ciliation as marker for staging. Both species go through the same developmental stages: prototroch, ventral ciliary field and ciliary bands. In both species the first neurons differenciate revealed by anti alpha-acetylated tubulin antibodies only and show no reaction with 5-HT or FMRFa antibodies. These neurons located at the anterior and posterior parts of the embryo in both species. In D. taeniatus embryons the anterior cell is transient and disappear just after head neuropil is constructed. On the contrary, in D. gyrociliatus embryos the anterior cell is not transient and remains at the same position during the whole life span of the specimen. Caudal cell is present during the whole embryogenesis in both species. Neurites of these early neurons surround the stomadeum and constitute anlagen of paired ventro-lateral longitudinal bundles. During the development the number of neurites increases and they form compact head neuropil, paired ventro-lateral and lateral longitudinal bundles, unpaired medial longitudinal bundle and transverse commissures in ventral hyposphere. Serotonin- and FMRFamide-immunoreactive neurons differentiate adjacent to ventro-lateral bundles and head neuropil, respectively, after the establishment of main structures of the nervous system at the ventral ciliary field and ciliary bands stages. Processes of serotonin-, FMRFamide- immunopositive neurons constitute the small portion of tubulin immunopositive neuropil at all described stages.ConclusionsWe announce a detailed data on the earliest events in D. gyrociliatus and D. taeniatus neurodevelopment based on anti-acetylated tubulin, serotonin, and FMRFamide-like immuno labeling. The first nerve elements demonstrate no 5-HT-IR and no FMRFa-IR, which differs from the most Polychaetes and even Lophotrochozoans, investigated so far. Moreover, these animals do not have a typical apical organ (or perhaps do not have it at all) and the pioneer neurons of D.gyrociliatus are also peculiar in that they join the definitive nervous system unlike other lophotrochozoans where pioneer nerons are transient. Thus, Dinophilus neurogenesis demonstrates a variation of common scheme. The reported study was funded by RFBR, project number 19-3460040.

scholarly journals Proteolysis and neurogenesis modulated by LNR domain proteins explosion support male differentiation in the crustacean Oithona nana

2019 ◽  
Author(s):  
Kevin Sugier ◽  
Romuald Laso-Jadart ◽  
Soheib Kerbache ◽  
Jos Kafer ◽  
Majda Arif ◽  
...  
Keyword(s):  
Nervous System ◽  
Amino Acid ◽  
Developmental Stages ◽  
System Development ◽  
Nervous System Development ◽  
Numerical Density ◽  
Female Ratio ◽  
Excitatory Neurotransmitter ◽  
Protein Protein Interaction ◽  
Sex Determination System

AbstractCopepods are the most numerous animals and play an essential role in the marine trophic web and biogeochemical cycles. The genus Oithona is described as having the highest numerical density, as the most cosmopolite copepod and iteroparous. The Oithona male paradox obliges it to alternate feeding (immobile) and mating (mobile) phases. As the molecular basis of this trade-off is unknown, we investigated this sexual dimorphism at the molecular level by integrating genomic, transcriptomic and protein-protein interaction analyses.While a ZW sex-determination system was predicted in O. nana, a fifteen-year time-series in the Toulon Little Bay showed a biased sex ratio toward females (male / female ratio < 0.15±0.11) highlighting a higher mortality in male. Here, the transcriptomic analysis of the five different developmental stages showed enrichment of Lin12-Notch Repeat (LNR) domains-containing proteins coding genes (LDPGs) in male transcripts. The male also showed enrichment in transcripts involved in proteolysis, nervous system development, synapse assembly and functioning and also amino acid conversion to glutamate. Moreover, several male down-regulated genes were involved in the increase of food uptake and digestion. The formation of LDP complexes was detected by yeast two-hybrid, with interactions involving proteases, extracellular matrix proteins and neurogenesis related proteins.Together, these results suggest that the O. nana male hypermotility is sustained by LDP-modulated proteolysis allowing the releases and conversions of amino acid into the excitatory neurotransmitter glutamate. This process could permit new axons and dendrites formation suggesting a sexual nervous system dimorphism. This could support the hypothesis of a sacrificial behaviour in males at the metabolic level.

scholarly journals Growing Glia: Cultivating Human Stem Cell Models of Gliogenesis in Health and Disease

2021 ◽  
Vol 9 ◽  
Author(s):  
Samantha N. Lanjewar ◽  
Steven A. Sloan
Keyword(s):  
Nervous System ◽  
Stem Cell ◽  
System Development ◽  
Stem Cell Differentiation ◽  
Nervous System Development ◽  
Model Systems ◽  
Human Stem Cell ◽  
Human Stem Cells ◽  
Health And Disease ◽  
Species Specific

Glia are present in all organisms with a central nervous system but considerably differ in their diversity, functions, and numbers. Coordinated efforts across many model systems have contributed to our understanding of glial-glial and neuron-glial interactions during nervous system development and disease, but human glia exhibit prominent species-specific attributes. Limited access to primary samples at critical developmental timepoints constrains our ability to assess glial contributions in human tissues. This challenge has been addressed throughout the past decade via advancements in human stem cell differentiation protocols that now offer the ability to model human astrocytes, oligodendrocytes, and microglia. Here, we review the use of novel 2D cell culture protocols, 3D organoid models, and bioengineered systems derived from human stem cells to study human glial development and the role of glia in neurodevelopmental disorders.

scholarly journals The development of early pioneer neurons in the annelid Malacoceros fuliginosus

2020 ◽  
Author(s):  
Suman Kumar ◽  
Sharat Chandra Tumu ◽  
Conrad Helm ◽  
Harald Hausen
Keyword(s):  
Nervous System ◽  
Synapse Formation ◽  
System Development ◽  
Posterior Pole ◽  
Nervous System Development ◽  
Whole Body ◽  
Neural Patterning ◽  
Neuronal Progenitors ◽  
Pioneer Neurons ◽  
Clonal Origin

Abstract Background Nervous system development is an interplay of many processes: the formation of individual neurons, which depends on whole-body and local patterning processes, and the coordinated growth of neurites and synapse formation. While knowledge of neural patterning in several animal groups is increasing, data on pioneer neurons that create the early axonal scaffold are scarce. Here we studied the first steps of nervous system development in the annelid Malacoceros fuliginosus . Results Here, we performed a dense expression profiling of a broad set of neural genes. We found that SoxB expression begins at 4 hours postfertilization, and shortly later, the neuronal progenitors can be identified at the anterior and the posterior pole by the transient and dynamic expression of proneural genes. At 9 hpf, the first neuronal cells start differentiating, and we provide a detailed description of axonal outgrowth of the pioneer neurons that create the primary neuronal scaffold. Tracing back the clonal origin of the ventral nerve cord pioneer neuron revealed that it is a descendant of the blastomere 2d (2d 221 ), which after 7 cleavages starts expressing Neurogenin , Achaete-Scute and NeuroD . Conclusions We propose that an anterior and posterior origin of the nervous system is ancestral in annelids. The specification of the relevant neurons starts very early and we suggest that closer examination of the first pioneer neurons will be valuable in better understanding of nervous system development in spirally cleaving animals, to determine the potential role of cell-intrinsic properties in neuronal specification and to resolve the evolution of nervous systems.

scholarly journals Dinophiliformia early neurogenesis suggests the evolution of conservative neural structures across the Annelida phylogenetic tree

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12386
Author(s):  
Elizaveta Fofanova ◽  
Tatiana D. Mayorova ◽  
Elena E. Voronezhskaya
Keyword(s):  
Nervous System ◽  
Developmental Stages ◽  
Life Cycles ◽  
Sensory Cells ◽  
Neuronal Marker ◽  
Acetylated Tubulin ◽  
Pioneer Neurons ◽  
Early Neurogenesis ◽  
Long Fibers ◽  
Peripheral Cells

Despite the increasing data concerning the structure of the adult nervous system in various Lophotrochozoa groups, the early events during the neurogenesis of rare and unique groups need clarification. Annelida are a diverse clade of Lophotrochozoa, and their representatives demonstrate a variety of body plans, lifestyles, and life cycles. Comparative data about the early development are available for Errantia, Sedentaria, Sipuncula, and Palaeoannelida; however, our knowledge of Dinophiliformia is currently scarce. Representatives of Dinophiliformia are small interstitial worms combining unique morphological features of different Lophotrochozoan taxa and expressing paedomorphic traits. We describe in detail the early neurogenesis of two related species: Dimorphilus gyrociliatus and Dinophilus vorticoides, from the appearance of first nerve cells until the formation of an adult body plan. In both species, the first cells were detected at the anterior and posterior regions at the early trochophore stage and demonstrated positive reactions with pan-neuronal marker anti-acetylated tubulin only. Long fibers of early cells grow towards each other and form longitudinal bundles along which differentiating neurons later appear and send their processes. We propose that these early cells serve as pioneer neurons, forming a layout of the adult nervous system. The early anterior cell of D. vorticoides is transient and present during the short embryonic period, while early anterior and posterior cells in D. gyrociliatus are maintained throughout the whole lifespan of the species. During development, the growing processes of early cells form compact brain neuropile, paired ventral and lateral longitudinal bundles; unpaired medial longitudinal bundle; and commissures in the ventral hyposphere. Specific 5-HT- and FMRFa-immunopositive neurons differentiate adjacent to the ventral bundles and brain neuropile in the middle trochophore and late trochophore stages, i.e. after the main structures of the nervous system have already been established. Processes of 5-HT- and FMRFa-positive cells constitute a small proportion of the tubulin-immunopositive brain neuropile, ventral cords, and commissures in all developmental stages. No 5-HT- and FMRFa-positive cells similar to apical sensory cells of other Lophotrochozoa were detected. We conclude that: (i) like in Errantia and Sedentaria, Dinophiliformia neurogenesis starts from the peripheral cells, whose processes prefigure the forming adult nervous system, (ii) Dinophiliformia early cells are negative to 5-HT and FMRFa antibodies like Sedentaria pioneer cells.

scholarly journals Dinophiliformia early neurogenesis suggests the evolution of conservative neural structures across the Annelida phylogenetic tree

2021 ◽  
Author(s):  
Elizaveta Fofanova ◽  
Tatiana Mayorova ◽  
Elena Voronezhskaya
Keyword(s):  
Nervous System ◽  
Developmental Stages ◽  
Life Cycles ◽  
Sensory Cells ◽  
Neuronal Marker ◽  
Acetylated Tubulin ◽  
Pioneer Neurons ◽  
Early Neurogenesis ◽  
Long Fibers ◽  
Peripheral Cells

Despite the increasing data concerning the structure of the adult nervous system in various Lophotrochozoa groups, the early events during the neurogenesis of rare and unique groups need clarification. Annelida are a diverse clade of Lophotrochozoa, and their representatives demonstrate a variety of body plans, lifestyles, and life cycles. Comparative data about the early development are available for Errantia, Sedentaria, Sipuncula and Palaeoannelida; however, our knowledge of Dinophiliformia is currently scarce. Representatives of Dinophiliformia are small interstitial worms combining unique morphological features of different Lophotrochozoan taxa and expressing paedomorphic traits. We describe in detail the early neurogenesis of two related species: Dimorphilus gyrociliatus and Dinophilus vorticoides, from the appearance of first nerve cells until the formation of an adult body plan. In both species, the first cells were detected at the anterior and posterior regions at the early trochophore stage and demonstrated positive reactions with pan-neuronal marker anti-acetylated tubulin only. Long fibers of early cells grow towards each other and form longitudinal bundles along which differentiating neurons later appear and send their processes. We propose that these early cells serve as pioneer neurons, forming a layout of the adult nervous system. The early anterior cell of D. vorticoides is transient and present during the short embryonic period, while early anterior and posterior cells in D. gyrociliatus are maintained throughout the whole lifespan of the species. During development, the growing processes of early cells form compact brain neuropile, paired ventral and lateral longitudinal bundles; unpaired medial longitudinal bundle; and commissures in the ventral hyposphere. Specific 5-HT- and FMRFa-immunopositive neurons differentiate adjacent to the ventral bundles and brain neuropile in the middle trochophore and late trochophore stages, i.e. after the main structures of the nervous system have already been established. Processes of 5-HT- and FMRFa-positive cells constitute a small proportion of the tubulin-immunopositive brain neuropile, ventral cords, and commissures in all developmental stages. No 5-HT- and FMRFa-positive cells similar to apical sensory cells of other Lophotrochozoa were detected. We conclude that: (i) like in Errantia and Sedentaria, Dinophiliformia neurogenesis starts from the peripheral cells, whose processes prefigure the forming adult nervous system, (ii) Dinophiliformia early cells are negative to 5-HT and FMRFa antibodies like Sedentaria pioneer cells.

scholarly journals The development of early pioneer neurons in the annelid Malacoceros fuliginosus

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Suman Kumar ◽  
Sharat Chandra Tumu ◽  
Conrad Helm ◽  
Harald Hausen
Keyword(s):  
Nervous System ◽  
Synapse Formation ◽  
System Development ◽  
Posterior Pole ◽  
Nervous System Development ◽  
Whole Body ◽  
Neural Patterning ◽  
Neuronal Progenitors ◽  
Pioneer Neurons ◽  
Clonal Origin

Abstract Background Nervous system development is an interplay of many processes: the formation of individual neurons, which depends on whole-body and local patterning processes, and the coordinated growth of neurites and synapse formation. While knowledge of neural patterning in several animal groups is increasing, data on pioneer neurons that create the early axonal scaffold are scarce. Here we studied the first steps of nervous system development in the annelid Malacoceros fuliginosus. Results We performed a dense expression profiling of a broad set of neural genes. We found that SoxB expression begins at 4 h postfertilization, and shortly later, the neuronal progenitors can be identified at the anterior and the posterior pole by the transient and dynamic expression of proneural genes. At 9 hpf, the first neuronal cells start differentiating, and we provide a detailed description of axonal outgrowth of the pioneer neurons that create the primary neuronal scaffold. Tracing back the clonal origin of the ventral nerve cord pioneer neuron revealed that it is a descendant of the blastomere 2d (2d221), which after 7 cleavages starts expressing Neurogenin, Acheate-Scute and NeuroD. Conclusions We propose that an anterior and posterior origin of the nervous system is ancestral in annelids. We suggest that closer examination of the first pioneer neurons will be valuable in better understanding of nervous system development in spirally cleaving animals, to determine the potential role of cell-intrinsic properties in neuronal specification and to resolve the evolution of nervous systems.

scholarly journals The neuron pioneering the ventral nerve cord does not follow the common pathway of neurogenesis in the polychaete Malacoceros fuliginosus

2020 ◽  
Author(s):  
Suman Kumar ◽  
Sharat Chandra Tumu ◽  
Conrad Helm ◽  
Harald Hausen
Keyword(s):  
Nervous System ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
System Development ◽  
Nervous System Development ◽  
Whole Body ◽  
Hierarchical Level ◽  
Major Influence ◽  
Extrinsic Factors ◽  
Pioneer Neurons

Abstract Background: Nervous system development is an interplay of many processes: the formation of individual neurons which depends on whole-body and local patterning processes and the coordinated growth of neurites and synapse formation. While knowledge of neural patterning in several animal groups is increasing, data on pioneer neurons that create the early axonal scaffold are scarce. Here we studied the early steps of nervous system development in the annelid Malacoceros fuliginosus.Results: We find that the first pioneer neurons are already in place in the anterior and posterior pole when broad neurogenesis is just starting. They do not express serotonin or FMRFamide which are commonly used markers in studies on nervous system architecture. A single posterior neuron prefigures the main course of the ventral nerve cord and this mode is probably ancestral for majority of annelids. Notably, none of the studied sox and proneural genes, which are commonly involved in the generation of neurons, is expressed by this important neuron. The only transcription factor we found expressed is Brn3, which likely acts on a low hierarchical level.Conclusions: We propose that the annelid ventral nerve cord pioneer neuron follows a highly divergent course of neurogenesis. The lack of Sox and proneural transcription factors, which are usually under control of patterning cell-extrinsic factors suggest a major influence of inherited cell-intrinsic properties on the development of this cell. Though cell-autonomous specification is generally an important pathway in the early development of spirally cleaving animals, its relevance for nervous system development is poorly understood. Our data suggest that closer investigation of the specification of pioneer neurons in animals featuring spiral cleavage will be highly informative to obtain a better understanding of how nervous systems form and evolve.

Antenatal Glucocorticoids Supplementation and Central Nervous System Development

2013 ◽  
Vol 14 (2) ◽  
pp. 160-166
Author(s):  
Diego Gazzolo ◽  
Laura D. Serpero ◽  
Alessandro Frigiola ◽  
Raul Abella ◽  
Alessandro Giamberti ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
System Development ◽  
Nervous System Development ◽  
Central Nervous System Development

scholarly journals Incorporation of 5-Bromo-2′-deoxyuridine into DNA and Proliferative Behavior of Cerebellar Neuroblasts: All That Glitters Is Not Gold

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1453
Author(s):  
Joaquín Martí-Clúa
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
System Development ◽  
Nervous System Development ◽  
Current Data ◽  
Cellular Mechanisms ◽  
Dividing Cells ◽  
The Central Nervous System ◽  
Repeated Doses ◽  
Pyrimidine Analog

The synthetic halogenated pyrimidine analog, 5-bromo-2′-deoxyuridine (BrdU), is a marker of DNA synthesis. This exogenous nucleoside has generated important insights into the cellular mechanisms of the central nervous system development in a variety of animals including insects, birds, and mammals. Despite this, the detrimental effects of the incorporation of BrdU into DNA on proliferation and viability of different types of cells has been frequently neglected. This review will summarize and present the effects of a pulse of BrdU, at doses ranging from 25 to 300 µg/g, or repeated injections. The latter, following the method of the progressively delayed labeling comprehensive procedure. The prenatal and perinatal development of the cerebellum are studied. These current data have implications for the interpretation of the results obtained by this marker as an index of the generation, migration, and settled pattern of neurons in the developing central nervous system. Caution should be exercised when interpreting the results obtained using BrdU. This is particularly important when high or repeated doses of this agent are injected. I hope that this review sheds light on the effects of this toxic maker. It may be used as a reference for toxicologists and neurobiologists given the broad use of 5-bromo-2′-deoxyuridine to label dividing cells.

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