scholarly journals Toxicity of 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NKK) in early development: a wide-scope metabolomics assay in zebrafish embryos

2021 ◽  
Author(s):  
Carla Merino ◽  
Marta Casado ◽  
Benjami Pina ◽  
Maria Vinaixa ◽  
Noelia Ramirez
Keyword(s):  
Early Development ◽  
Developmental Stages ◽  
Excision Repair ◽  
Environmental Pollutant ◽  
Zebrafish Embryos ◽  
Wide Scope ◽  
Base Excision ◽  
Mammalian Toxicity ◽  
The Impact ◽  
Early Developmental

The tobacco-specific nitrosamine 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a carcinogenic and ubiquitous environmental pollutant which carcinogenic and cytotoxic activity has been thoroughly investigated in murine models and human tissues. However, its potential deleterious effects on vertebrate early development are yet poorly understood. In this work, we characterized the impact of NNK exposure during early developmental stages of zebrafish embryos, a known alternative model for mammalian toxicity studies. Embryos exposed to different NNK concentrations were monitored for lethality and for the appearance of malformations during the first five days after fertilization. LC/MS-based untargeted metabolomics was subsequently performed for a wide-scope assay of NNK-related metabolic alterations. Our results revealed the presence of not only the parental compound, but also of two NKK known metabolites, 4-Hydroxy-4-(3-pyridyl)-butyric acid (HPBA) and 4-(Methylnitrosamino)-1-(3-pyridyl-N-oxide)-1-butanol (NNAL-N-oxide) in exposed embryos likely resulting from active CYP450-mediated α-hydroxylation and NNK detoxification pathways, respectively. This was paralleled by a disruption in purine and pyrimidine metabolisms and the activation of the base excision repair pathway. Our results confirm NNK as a harmful embryonic agent and demonstrate zebrafish embryos to be a suitable early development model to monitor NNK toxicity.

scholarly journals Zebrafish lipid droplets regulate embryonic ATP homeostasis to power early development

Open Biology ◽  
2017 ◽  
Vol 7 (7) ◽  
pp. 170063 ◽  
Author(s):  
Asmita Dutta ◽  
Deepak Kumar Sinha
Keyword(s):  
Fatty Acids ◽  
Early Development ◽  
Lipid Droplets ◽  
Developmental Stages ◽  
Fatty Acyl ◽  
Zebrafish Embryos ◽  
Early Developmental Stages ◽  
Successful Execution ◽  
Acyl Coenzyme A ◽  
Early Developmental

In zebrafish embryos, the maternally supplied pool of ATP is insufficient to power even the earliest of developmental events (0–3 hpf) such as oocyte-to-embryo transition (OET). The embryos generate an additional pulse (2.5 h long) of ATP (1.25–4 hpf) to achieve the embryonic ATP homeostasis. We demonstrate that the additional pulse of ATP is needed for successful execution of OET. The maternally supplied yolk lipids play a crucial role in maintaining the embryonic ATP homeostasis. In this paper, we identify the source and trafficking routes of free fatty acids (FFAs) that feed the mitochondria for synthesis of ATP. Interestingly, neither the maternally supplied pool of yolk-FFA nor the yolk-FACoA (fatty acyl coenzyme A) is used for ATP homeostasis during 0–5 hpf in zebrafish embryos. With the help of lipidomics, we explore the link between lipid droplet (LD)-mediated lipolysis and ATP homeostasis in zebrafish embryos. Until 5 hpf, the embryonic LDs undergo extensive lipolysis that generates FFAs. We demonstrate that these newly synthesized FFAs from LDs are involved in the maintenance of embryonic ATP homeostasis, rather than the FFAs/FACoA present in the yolk. Thus, the LDs are vital embryonic organelles that maintain the ATP homeostasis during early developmental stages (0–5 hpf) in zebrafish embryos. Our study highlights the important roles carried on by the LDs during the early development of the zebrafish embryos.

scholarly journals Microarray analysis of gene expression during early development: a cautionary overview

Reproduction ◽  
2010 ◽  
Vol 140 (6) ◽  
pp. 787-801 ◽  
Author(s):  
Claude Robert
Keyword(s):  
Gene Expression ◽  
Early Development ◽  
Microarray Analysis ◽  
Developmental Stages ◽  
Sample Handling ◽  
Early Embryos ◽  
High Throughput Method ◽  
Full Benefit ◽  
Key Steps ◽  
Early Developmental

The rise of the ‘omics’ technologies started nearly a decade ago and, among them, transcriptomics has been used successfully to contrast gene expression in mammalian oocytes and early embryos. The scarcity of biological material that early developmental stages provide is the prime reason why the field of transcriptomics is becoming more and more popular with reproductive biologists. The potential to amplify scarce mRNA samples and generate the necessary amounts of starting material enables the relative measurement of RNA abundance of thousands of candidates simultaneously. So far, microarrays have been the most commonly used high-throughput method in this field. Microarray platforms can be found in a wide variety of formats, from cDNA collections to long or short oligo probe sets. These platforms generate large amounts of data that require the integration of comparative RNA abundance values in the physiological context of early development for their full benefit to be appreciated. Unfortunately, significant discrepancies between datasets suggest that direct comparison between studies is difficult and often not possible. We have investigated the sample-handling steps leading to the generation of microarray data produced from prehatching embryo samples and have identified key steps that significantly impact the downstream results. This review provides a discussion on the best methods for the preparation of samples from early embryos for microarray analysis and focuses on the challenges that impede dataset comparisons from different platforms and the reasons why methodological benchmarking performed using somatic cells may not apply to the atypical nature of prehatching development.

Chromatin diminution is strictly correlated to somatic cell behavior in early development of the nematode Parascaris univalens

1995 ◽  
Vol 108 (6) ◽  
pp. 2393-2404
Author(s):  
M.R. Esteban ◽  
G. Giovinazzo ◽  
C. Goday
Keyword(s):  
Somatic Cell ◽  
Early Development ◽  
Cytochalasin B ◽  
Developmental Stages ◽  
Cell Behavior ◽  
Chromatin Diminution ◽  
Developmental Behavior ◽  
Licl Treatment ◽  
The Relationship ◽  
Early Developmental

We have studied the relationship between the occurrence of chromatin diminution and the developmental behavior of somatic blastomeres in early development of the nematode Parascaris univalens. A cytological and immunocytochemical analysis of chromatin diminution was performed in P. univalens embryos exposed to ‘vegetalizing’ (LiCl) and ‘animalizing’ (NaSCN) substances during early developmental stages. We have also analyzed chromatin diminution in embryos displaying only symmetrical ‘somatic-like’ divisions due to a brief cytochalasin B treatment at the pronuclear stage. The results show that LiCl treatment induces chromatin diminution in P0-P4 pregerminal blastomeres while NaSCN treatment prevents it. Pregerminal cells undergoing chromatin diminution in ‘vegetalized’ embryos behaved like somatic cells with respect to division and cleavage patterns. NaSCN treatment results in undiminuted polynucleated embryos that are not capable of cleavage. In cytochalasin B-pulsed embryos, chromatin diminution occurs in all blastomeres. From our results we conclude that chromatin diminution and somatic cell behavior are not separable and constitute strictly correlated events in Parascaris. Moreover, the results indicate that the segregation of the cytoplasmic factors involved in chromatin diminution in early Parascaris development are microfilament-mediated. Here, we also report the formation of a latter pregerminal cell precursor (P5) not susceptible to LiCl-induced chromatin diminution.

Development of pigment-cup eyes in the polychaetePlatynereis dumeriliiand evolutionary conservation of larval eyes in Bilateria

Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1143-1154 ◽  
Author(s):  
Detlev Arendt ◽  
Kristin Tessmar ◽  
Maria-Ines Medeiros de Campos-Baptista ◽  
Adriaan Dorresteijn ◽  
Joachim Wittbrodt
Keyword(s):  
Visual System ◽  
Early Development ◽  
Developmental Stages ◽  
Photoreceptor Cells ◽  
Evolutionary Conservation ◽  
Early Developmental Stages ◽  
Platynereis Dumerilii ◽  
Differentiation Marker ◽  
Early Developmental

The role of Pax6 in eye development in insects and vertebrates supports the view that their eyes evolved from simple pigment-cup ocelli present in their last common ancestors (Urbilateria). The cerebral eyes in errant polychaetes represent prototype invertebrate pigment-cup ocelli and thus resemble the presumed ancestral eyes. We have analysed expression of conserved eye specification genes in the early development of larval and adult pigment-cup eyes in Platynereis dumerilii (Polychaeta, Annelida, Lophotrochozoa). Both larval and adult eyes form in close vicinity of the optic anlagen on both sides of the developing brain ganglia. While pax6 is expressed in the larval, but not in the developing, adult eyes, expression of six1/2 from trochophora stages onwards specifically outlines the optic anlagen and thus covers both the developing larval and adult eyes. Using Platynereis rhabdomeric opsin as differentiation marker, we show that the first pair of adult eye photoreceptor cells is detected within bilateral clusters that transitorily express ath, the Platynereis atonal orthologue, thus resembling proneural sensory clusters. Our data indicate that – similar to insects, but different from the vertebrates – polychaete six1/2 expression outlines the entire visual system from early developmental stages onwards and ath-positive clusters generate the first photoreceptor cells to appear. We propose that pax6-, six1/2- and ath-positive larval eyes, as found in today’s trochophora, were present already in Urbilateria.

scholarly journals The effects of subchronic exposure to ketoprofen on early developmental stages of common carp

2013 ◽  
Vol 82 (3) ◽  
pp. 343-347 ◽  
Author(s):  
Eva Prášková ◽  
Stanislava Štěpánová ◽  
Lucie Chromcová ◽  
Lucie Plhalová ◽  
Eva Voslářová ◽  
...  
Keyword(s):  
Common Carp ◽  
Surface Waters ◽  
Developmental Stages ◽  
Experimental Conditions ◽  
Environmental Concentration ◽  
Negative Effect ◽  
Rate Evaluation ◽  
The Impact ◽  
Early Developmental

Ketoprofen residues have been found in surface water where they present a potential risk to nontarget aquatic species. The aim of this study was to assess the impact of ketoprofen in surface waters on fish under experimental conditions. Subchronic toxic effects on 300 embryos and larvae of common carp (Cyprinus carpio) were investigated during a 30 day toxicity test with concentrations of ketoprofen: 0.003, 2.1, 6.3 and 21 mg/l. The exposure to ketoprofen showed no effect on mortality, but we observed significant delay (P < 0.05) in hatching in day 3 in fish exposed to all concentrations of ketoprofen. Significant delays (P < 0.05) in development were revealed at 2.1, 6.3 and 21 mg/l ketoprofen. On the basis of weight and growth rate evaluation and the determination of developmental stages, the lowest observed effect concentration was 0.003 mg/l. According to these results, the reported environmental concentration of ketoprofen in Czech rivers could have a negative effect on the growth and development of carp embryos and larvae. These tests have not yet been performed. Further research and search for a mechanism to reduce the incidence of ketoprofen in the waters by better wastewater treatment is required.

scholarly journals 1H NMR chemical exchange techniques reveal local and global effects of oxidized cytosine derivatives

2021 ◽  
Author(s):  
Romeo Cosimo Arrigo Dubini ◽  
Eva Korytiaková ◽  
Thea Schinkel ◽  
Pia Heinrichs ◽  
Thomas Carell ◽  
...  
Keyword(s):  
Base Pair ◽  
Chemical Exchange ◽  
Excision Repair ◽  
Epigenetic Modification ◽  
Conformational Exchange ◽  
Epigenetic Mark ◽  
Dna Strands ◽  
Domains Of Life ◽  
Base Excision ◽  
The Impact

5-carboxycytosine (5caC) is a rare epigenetic modification found in nucleic acids of all domains of life. Despite its sparse genomic abundance, 5caC is presumed to play essential regulatory roles in transcription, maintenance and base-excision processes in DNA. In this work, we utilize nuclear magnetic resonance (NMR) spectroscopy to address the effects of 5caC incorporation into canonical DNA strands at multiple pH and temperature conditions. Our results demonstrate that 5caC has a pH-dependent global destabilizing and a base-pair mobility enhancing local impact on dsDNA, albeit without any detectable influence on the ground-state B-DNA structure. Measurement of hybridization thermodynamics and kinetics of 5caC-bearing DNA duplexes highlighted how acidic environment (pH 5.8 and 4.7) destabilizes the double-stranded structure by ≈10-20 kJ mol-1 at 37 °C when compared to the same sample at neutral pH. Protonation of 5caC results in a lower activation energy for the dissociation process and a higher barrier for annealing. Studies on conformational exchange on the µs time scale regime revealed a sharply localized base-pair motion involving exclusively the modified site and its immediate surroundings. By direct comparison with canonical and 5-formylcytosine (5fC)-edited strands, we were able to address the impact of the two most oxidized naturally occurring cytosine derivatives in the genome. These insights on 5caC's subtle sensitivity to acidic pH contribute to the long standing questions of its capacity as a substrate in base excision repair processes and its purpose as an independent, stable epigenetic mark.

Potential and limitations of bovine-specific arrays for the analysis of mRNA levels in early development: preliminary analysis using a bovine embryonic array

2005 ◽  
Vol 17 (2) ◽  
pp. 47 ◽  
Author(s):  
Marc-André Sirard ◽  
Isabelle Dufort ◽  
Maud Vallée ◽  
Lyne Massicotte ◽  
Catherine Gravel ◽  
...  
Keyword(s):  
Early Development ◽  
Developmental Stages ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Mrna Level ◽  
Cdna Array ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Mrna Levels ◽  
The Impact

New insights into the early development of large mammals are becoming available through the measurement of differential mRNA levels in oocytes and preimplantation embryos. These advances in knowledge are rapidly picking up in pace, mainly owing to the advantages brought by new molecular biology approaches being developed. The possibility of amplifying the starting material and therefore making measurements in single embryo units is now feasible. With these tools, the evaluation of variations in gene expression patterns during the preimplantation period or the impact of culture on mRNA levels is now possible. However, it is important to keep in mind that these methods still have limitations associated with sample preparation or the use of the appropriate controls. Even proper methods of analysis are very important to achieve the full benefit of the application of these tools. The present paper describes some of the potential, as well as limitations, of mRNA level analysis in early embryos, especially for microarray analysis. We have generated a bovine cDNA array (>2000 clones) that contains expressed sequence tags (ESTs) collected from various preimplantation development stages. Using this chip, we have initiated the characterisation of global mRNA level patterns of several key developmental stages from the immature oocyte to the blastocyst stage. As expected, the hybridisation results indicate very different expression profiles involving hundreds of genes when comparing oocyte and blastocyst samples to a reference mRNA sample made from a pool of ESTs from pooled somatic tissues. Although this array is still in its preliminary stage and the EST bank has not been processed to contain only unigenes, it is already a very useful tool for discovering candidate genes that may play important roles during early embryonic life.

scholarly journals Early development of Hypogymnia physodes (L.) Nyl. in response to emissions from a copper smelter

2001 ◽  
Vol 33 (6) ◽  
pp. 527-538 ◽  
Author(s):  
Irina N. Mikhailova ◽  
Christoph Scheidegger
Keyword(s):  
Early Development ◽  
Developmental Stages ◽  
Developmental Rate ◽  
Copper Smelter ◽  
Copper Smelting ◽  
Hypogymnia Physodes ◽  
Toxic Impact ◽  
Early Developmental ◽  
Desert Zone ◽  
Copper Smelting Plant

AbstractThe early development of Hypogymnia physodes from soredia to the formation of stratified lobes has been studied experimentally in the vicinity of a copper-smelting plant in theMiddle Urals. SEM investigations combined with life table analyses of early developmental stages revealed decreases in soredial survival and developmental rate in polluted localities. Non-stricatified pre-thallus stages without an epicortex were tolerant to toxic impact and were able to survive even in the zone with the highest pollution (lichen desert zone). The sensitivity of developmental stagesancreased after stratified lobes had developed.

scholarly journals A Mathematical Model for DNA Damage and Repair

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Philip S. Crooke ◽  
Fritz F. Parl
Keyword(s):  
Mathematical Model ◽  
Dna Damage ◽  
Dna Adducts ◽  
Excision Repair ◽  
Estrogen Metabolism ◽  
Enzymatic Reactions ◽  
Dna Damage And Repair ◽  
Base Excision ◽  
The Impact ◽  
Variant Enzyme

In cells, DNA repair has to keep up with DNA damage to maintain the integrity of the genome and prevent mutagenesis and carcinogenesis. While the importance of both DNA damage and repair is clear, the impact of imbalances between both processes has not been studied. In this paper, we created a combined mathematical model for the formation of DNA adducts from oxidative estrogen metabolism followed by base excision repair (BER) of these adducts. The model encompasses a set of differential equations representing the sequence of enzymatic reactions in both damage and repair pathways. By combining both pathways, we can simulate the overall process by starting from a given time-dependent concentration of 17β-estradiol (E2) and2′-deoxyguanosine, determine the extent of adduct formation and the correction by BER required to preserve the integrity of DNA. The model allows us to examine the effect of phenotypic and genotypic factors such as different concentrations of estrogen and variant enzyme haplotypes on the formation and repair of DNA adducts.

scholarly journals Oxidative stress-mediated epigenetic regulation by G-quadruplexes

NAR Cancer ◽  
2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Aaron M Fleming ◽  
Cynthia J Burrows
Keyword(s):  
Oxidative Stress ◽  
Base Excision Repair ◽  
Excision Repair ◽  
Gene Promoter ◽  
Nuclease Activity ◽  
G Quadruplex ◽  
Biophysical Studies ◽  
Base Excision ◽  
The Impact

Abstract Many cancer-associated genes are regulated by guanine (G)-rich sequences that are capable of refolding from the canonical duplex structure to an intrastrand G-quadruplex. These same sequences are sensitive to oxidative damage that is repaired by the base excision repair glycosylases OGG1 and NEIL1–3. We describe studies indicating that oxidation of a guanosine base in a gene promoter G-quadruplex can lead to up- and downregulation of gene expression that is location dependent and involves the base excision repair pathway in which the first intermediate, an apurinic (AP) site, plays a key role mediated by AP endonuclease 1 (APE1/REF1). The nuclease activity of APE1 is paused at a G-quadruplex, while the REF1 capacity of this protein engages activating transcription factors such as HIF-1α, AP-1 and p53. The mechanism has been probed by in vitro biophysical studies, whole-genome approaches and reporter plasmids in cellulo. Replacement of promoter elements by a G-quadruplex sequence usually led to upregulation, but depending on the strand and precise location, examples of downregulation were also found. The impact of oxidative stress-mediated lesions in the G-rich sequence enhanced the effect, whether it was positive or negative.

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