scholarly journals Neural selective activation and temporal regulation of a mammalian GAP-43 promoter in zebrafish

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1767-1775 ◽  
Author(s):  
E. Reinhard ◽  
E. Nedivi ◽  
J. Wegner ◽  
J.H. Skene ◽  
M. Westerfield

Neurons throughout the vertebrate nervous system selectively activate the gene for a growth cone component, GAP-43, during embryonic development, and then decrease its expression abruptly as they form synapses. Distal interruption of mature axons in the central nervous system (CNS) of fish and amphibians, but not in the mammalian CNS reverses the developmental down-regulation of GAP-43 expression. To explore functional conservation and divergence of cis-acting elements that regulate expression of the GAP-43 gene, we studied activation, in transgenic zebrafish embryos, of mammalian GAP-43 genomic sequences fused to a marker gene. The DNA fragments containing the GAP-43 promoter, including a short fragment of 386 base pairs, were preferentially activated in the embryonic fish nervous system at times when extensive neuronal differentiation and neurite outgrowth take place. After 2 days of development, expression of the mammalian transgenes was specifically downregulated in the fish spinal cord but increased in more rostral regions of the CNS. This expression pattern was well correlated with the regulation of the endogenous fish GAP-43 gene revealed by in situ hybridization. Elements of the mammalian gene located a substantial distance upstream of the minimal promoter directed additional expression of the marker gene in a specific set of non-neural cells in zebrafish embryos. Our results indicate that cis-acting elements of the GAP-43 gene, and signaling pathways controlling these elements during embryonic development, have been functionally conserved in vertebrate evolution.

Open Biology ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 190245
Author(s):  
Eléanor Simon ◽  
Sergio Fernández de la Puebla ◽  
Isabel Guerrero

Specific neuropeptides regulate in arthropods the shedding of the old cuticle (ecdysis) followed by maturation of the new cuticle. In Drosophila melanogaster , the last ecdysis occurs at eclosion from the pupal case, with a post-eclosion behavioural sequence that leads to wing extension, cuticle stretching and tanning. These events are highly stereotyped and are controlled by a subset of crustacean cardioactive peptide (CCAP) neurons through the expression of the neuropeptide Bursicon (Burs). We have studied the role of the transcription factor Odd-paired (Opa) during the post-eclosion period. We report that opa is expressed in the CCAP neurons of the central nervous system during various steps of the ecdysis process and in peripheral CCAP neurons innerving the larval muscles involved in adult ecdysis. We show that its downregulation alters Burs expression in the CCAP neurons. Ectopic expression of Opa, or the vertebrate homologue Zic2 , in the CCAP neurons also affects Burs expression, indicating an evolutionary functional conservation. Finally, our results show that, independently of its role in Burs regulation, Opa prevents death of CCAP neurons during larval development.


2010 ◽  
Vol 79 (3) ◽  
pp. 1363-1373 ◽  
Author(s):  
Jianchun Xiao ◽  
Lorraine Jones-Brando ◽  
C. Conover Talbot ◽  
Robert H. Yolken

ABSTRACTStrain type is one of the key factors suspected to play a role in determining the outcome ofToxoplasmainfection. In this study, we examined the transcriptional profile of human neuroepithelioma cells in response to representative strains ofToxoplasmaby using microarray analysis to characterize the strain-specific host cell response. The study of neural cells is of interest in light of the ability ofToxoplasmato infect the brain and to establish persistent infection within the central nervous system. We found that the extents of the expression changes varied considerably among the three strains. Neuroepithelial cells infected withToxoplasmatype I exhibited the highest level of differential gene expression, whereas type II-infected cells had a substantially smaller number of genes which were differentially expressed. Cells infected with type III exhibited intermediate effects on gene expression. The three strains also differed in the individual genes and gene pathways which were altered following cellular infection. For example, gene ontology (GO) analysis indicated that type I infection largely affects genes related to the central nervous system, while type III infection largely alters genes which affect nucleotide metabolism; type II infection does not alter the expression of a clearly defined set of genes. Moreover, Ingenuity Pathways Analysis (IPA) suggests that the three lineages differ in the ability to manipulate their host; e.g., they employ different strategies to avoid, deflect, or subvert host defense mechanisms. These observed differences may explain some of the variation in the neurobiological effects of different strains ofToxoplasmaon infected individuals.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vydianathan Ravi ◽  
Shipra Bhatia ◽  
Prashant Shingate ◽  
Boon-Hui Tay ◽  
Byrappa Venkatesh ◽  
...  

AbstractThe transcription factor Pax6 is crucial for the development of the central nervous system, eye, olfactory system and pancreas, and is implicated in human disease. While a single Pax6 gene exists in human and chicken, Pax6 occurs as a gene family in other vertebrates, with two members in elephant shark, Xenopus tropicalis and Anolis lizard and three members in teleost fish such as stickleback and medaka. However, the complement of Pax6 genes in jawless vertebrates (cyclostomes), the sister group of jawed vertebrates (gnathostomes), is unknown. Using a combination of BAC sequencing and genome analysis, we discovered three Pax6 genes in lampreys. Unlike the paired-less Pax6 present in some gnathostomes, all three lamprey Pax6 have a highly conserved full-length paired domain. All three Pax6 genes are expressed in the eye and brain, with variable expression in other tissues. Notably, lamprey Pax6α transcripts are found in the pancreas, a vertebrate-specific organ, indicating the involvement of Pax6 in development of the pancreas in the vertebrate ancestor. Multi-species sequence comparisons revealed only a single conserved non-coding element, in the lamprey Pax6β locus, with similarity to the PAX6 neuroretina enhancer. Using a transgenic zebrafish enhancer assay we demonstrate functional conservation of this element over 500 million years of vertebrate evolution.


2013 ◽  
Vol 47 (7) ◽  
pp. 3316-3325 ◽  
Author(s):  
Nga Yu Ho ◽  
Lixin Yang ◽  
Jessica Legradi ◽  
Olivier Armant ◽  
Masanari Takamiya ◽  
...  

2001 ◽  
Vol 81 (2) ◽  
pp. 871-927 ◽  
Author(s):  
Nicole Baumann ◽  
Danielle Pham-Dinh

Oligodendrocytes, the myelin-forming cells of the central nervous system (CNS), and astrocytes constitute macroglia. This review deals with the recent progress related to the origin and differentiation of the oligodendrocytes, their relationships to other neural cells, and functional neuroglial interactions under physiological conditions and in demyelinating diseases. One of the problems in studies of the CNS is to find components, i.e., markers, for the identification of the different cells, in intact tissues or cultures. In recent years, specific biochemical, immunological, and molecular markers have been identified. Many components specific to differentiating oligodendrocytes and to myelin are now available to aid their study. Transgenic mice and spontaneous mutants have led to a better understanding of the targets of specific dys- or demyelinating diseases. The best examples are the studies concerning the effects of the mutations affecting the most abundant protein in the central nervous myelin, the proteolipid protein, which lead to dysmyelinating diseases in animals and human (jimpy mutation and Pelizaeus-Merzbacher disease or spastic paraplegia, respectively). Oligodendrocytes, as astrocytes, are able to respond to changes in the cellular and extracellular environment, possibly in relation to a glial network. There is also a remarkable plasticity of the oligodendrocyte lineage, even in the adult with a certain potentiality for myelin repair after experimental demyelination or human diseases.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jerusha Naidoo ◽  
Deborah Young

Substantial progress has been made in the development of novel gene therapy strategies for central nervous system (CNS) disorders in recent years. However, unregulated transgene expression is a significant issue limiting human applications due to the potential side effects from excessive levels of transgenic protein that indiscriminately affect both diseased and nondiseased cells. Gene regulation systems are a tool by which tight tissue-specific and temporal regulation of transgene expression may be achieved. This review covers the features of ideal regulatory systems and summarises the mechanics of current exogenous and endogenous gene regulation systems and their utility in the CNS.


2018 ◽  
Vol 98 (1) ◽  
pp. 239-389 ◽  
Author(s):  
Alexei Verkhratsky ◽  
Maiken Nedergaard

Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.


2016 ◽  
Vol 74 (8) ◽  
pp. 671-678 ◽  
Author(s):  
Roberto E. Sica ◽  
Roberto Caccuri ◽  
Cecilia Quarracino ◽  
Francisco Capani

ABSTRACT Experimental evidence suggests that astrocytes play a crucial role in the physiology of the central nervous system (CNS) by modulating synaptic activity and plasticity. Based on what is currently known we postulate that astrocytes are fundamental, along with neurons, for the information processing that takes place within the CNS. On the other hand, experimental findings and human observations signal that some of the primary degenerative diseases of the CNS, like frontotemporal dementia, Parkinson’s disease, Alzheimer’s dementia, Huntington’s dementia, primary cerebellar ataxias and amyotrophic lateral sclerosis, all of which affect the human species exclusively, may be due to astroglial dysfunction. This hypothesis is supported by observations that demonstrated that the killing of neurons by non-neural cells plays a major role in the pathogenesis of those diseases, at both their onset and their progression. Furthermore, recent findings suggest that astrocytes might be involved in the pathogenesis of some psychiatric disorders as well.


2019 ◽  
Author(s):  
Haijun Zhang ◽  
Yu Gao ◽  
Zhangji Dong ◽  
Wenjin Hao ◽  
Dong Liu ◽  
...  

Abstract Background: Rab proteins are GTPases responsible for intracellular vesicular trafficking regulation. Rab11 proteins, members of the Rab GTPase family, are known to regulate vesicular recycling during embryonic development. In zebrafish, there are 3 rab11 paralogues, known as rab11a, rab11ba and rab11bb, sharing high identity with each other. However, the expression analysis of rab11 is so far lacking. Results: Here, by phylogeny analysis, we found the three rab11 genes are highly conserved especially for their GTPase domains. We examined the expression patterns of rab11a, rab11ba and rab11bb using RT-PCR and in situ hybridization. We found that all the three genes were highly enriched in the central nervous system, but in different areas of the brain. Apart from brain, rab11a was also expressed in caudal vein, pronephric duct, proctodeum, pharyngeal arches and digestive duct, rab11ba was detected to express in muscle, and rab11bb was expressed in kidney, fin and spinal cord. Different from rab11a and rab11ba, which both have maternal expressions in embryos, rab11bb only expresses during 24hpf to 96hpf. Conclusions: Our results suggest that rab11 genes play important but distinct roles in the development of the nervous system in zebrafish. The findings could provide new evidences for better understanding the functions of rab11 in the development of zebrafish embryos.


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