Transmission of the EGFP Transgene in Zebrafish Progeny

Although the number of vaping-related deaths in the US is rising, the specific cause remains unidentified. Therefore, determining what long-term effects vegetable glycerin (VG) and propylene glycol (PG), the main non-nicotine components in e-cigarettes, may have is crucial. Discovering that these components are harmful when tested on fruit flies (Drosophila melanogaster), a model organism, may suggest similar effects in humans. In this study, the number of offspring, changes in behavior, and phenotypic mutations in fruit flies were observed for the parent, F1, and F2 generations after the parent generation was exposed to one of four treatments of aerosolized solution. These included a 50% PG/50% VG, a 30% PG/70% VG, a 70% PG/30% VG, or no solution (control) using a nebulizer for 18 seconds each day, for two days. It was found that each experimental group had fewer offspring than the control. A two-sample T-test (α = 0.05) was used to find that the size of the flies in the F1 generation was statistically significantly smaller in ⅔ of the experimental groups when compared to the control. Furthermore, it was observed using a two-proportion Z-test (α = 0.05) that ⅔ of experimental groups in the parent generation, and all F1 experimental groups were statistically significantly more likely to develop at least one phenotypic mutation than the control. Additionally statistically significant changes were seen in activity patterns and reflex immediately after exposure. Overall, it is probable that exposure to aerosolized VG and PG is a major problem. Although the number of vaping-related deaths in the US is rising, the specific cause remains unidentified. Therefore, determining what long-term effects vegetable glycerin (VG) and propylene glycol (PG), the main non-nicotine components in e-cigarettes, may have is crucial. Discovering that these components are harmful when tested on fruit flies (Drosophila melanogaster), a model organism, may suggest similar effects in humans. In this study, the number of offspring, changes in behavior, and phenotypic mutations in fruit flies were observed for the parent, F1, and F2 generations after the parent generation were exposed to one of four treatments of aerosolized solution. These included a 50% PG/50% VG, a 30% PG/70% VG, a 70% PG/30% VG, or no solution (control) using a nebulizer for 18 seconds each day, for two days. It was found that each experimental group had fewer offspring than the control. A two-sample T-test (α = 0.05) was used to find that the size of the flies in the F1 generation was statistically significantly smaller in ⅔ of the experimental groups when compared to the control. Furthermore, it was observed using a two-proportion Z-test (α = 0.05) that ⅔ of experimental groups in the parent generation, and all F1 experimental groups were statistically significantly more likely to develop at least one phenotypic mutation than the control. Additionally statistically significant changes were seen in activity patterns and reflex immediately after exposure. Overall, it is probable that exposure to aerosolized VG and PG is a major problem.

Background: Zebrafish (Danio rerio) are now a prime model organism in biomedical research due to their genetic similarity to humans, optical transparency in early development stages, and ability to be genetically manipulated with ease. With the prohibition of animal dissection after 2014, and the stringent ethical requirements for the use of rodents such as mice and rats, zebrafish offer a convenient alternative model for disease studies. Their small size, rapid embryonic development, and capacity for recapitulating human disease phenotypes make them particularly suited for the study of multifaceted diseases, like cancer, neurodegenerative diseases, and cardiovascular disease as compared to other model organisms. Aims: The following review aims to investigate the growing value of zebrafish as a model organism in disease research and highlight improvements in cell imaging technologies that further enhance their merit. It also highlights their potential to replace traditional mammalian models in future biomedical research because of ethical, logistical, and experimental advantages. Materials and Methods: The findings of previous scientific research studies and research articles that employed zebrafish as a model system in disease-related research have been gathered and summarized. A literature review was conducted to denote the way that zebrafish have been employed together with advanced imaging techniques to explore a variety of human diseases. Results: Evolution of cell imaging technology has made high-resolution visualization of complex cell and molecular functions possible in zebrafish. It has been demonstrated through research that zebrafish model well most forms of human disorders, and one can achieve experiment outcomes within a short time frame as they grow rapidly. In addition, use of zebrafish circumvents some of the ethical challenges posed by traditional rodent models. Conclusion: The combination of zebrafish as a model organism and high-class cell imaging technologies presents an unprecedented platform for therapeutic design, drug discovery, and disease modelling. With their many advantages and fewer ethical constraints, the zebrafish are poised to become a major model system in future biomedical and translational research.

To address concerns related with incidental release of transgenic zebrafish (Danio rerio) in water bodies, experiments were carried out to document aggressive behaviour (Experiment 1) of transgenic zebrafish towards wildtype zebrafish and flying barb (Esomus danricus). The study also aimed to evaluate their susceptibility to predation (Experiment 2) by snakehead, Channa striatus. In Experiment 1, 15 replicate trials were performed to document aggressive encounters with the following treatments: (1) transgenic zebrafish, monotypic; (2) wildtype zebrafish, monotypic; (3) flying barb, monotypic; (4) transgenic and wildtype zebrafish, polytypic, stocked at 1:1; (5) flying barb and transgenic zebrafish, polytypic, stocked at 1:1; and (6) flying barb and wildtype zebrafish, polytypic, stocked at 1:1. The wildtype zebrafish and flying barb preferred to shoal with fish of similar phenotype in monotypic treatments (2 and 3, respectively), compared to Treatment 6, when more aggression was noticed (P < 0.05). However, when placed with the transgenic zebrafish, both flying barb (Treatment 5) and wildtype zebrafish (Treatment 4) were significantly less aggressive (P < 0.05). Experiment 2 consisted of 15 replicate trials, wherein 10 randomly selected prey were placed into a test aquarium, already containing a snakehead. The treatments were: (1) transgenic and wildtype zebrafish, stocked at 1:1; (2) flying barb and transgenic zebrafish, stocked at 1:1; and (3) flying barb and wildtype zebrafish, stocked at 1:1. Uneaten prey were counted after 12 h. The snakehead consumed 30.6–34.6%, 52–61.4% and 45.4–58.6% of transgenic zebrafish, wildtype zebrafish and flying barb, respectively. The snakehead appeared to avoid the transgenic zebrafish, compared to wildtype zebrafish and flying barb (P < 0.05). The experiments illustrate behavioural mechanisms by which transgenic zebrafish may negatively impact wildtype zebrafish and flying barb under confined conditions in shrinking water bodies, particularly when there is no escape and there is presence of predators like snakehead.

Zebrafish (Danio rerio) is a tropical freshwater fish, lives in South Asia, India, and Pakistan. The use of zebrafish as a model organism in embryology and genetic studies of vertebrates was first mentioned by George Streisinger. Zebrafish has become a popular vertebrate model organism for biomedical research due to its numerous advantages. Zebrafish genome has homologues of 70% human genes, 80% of which are associated with human diseases. Zebrafish embryos are transparent, developes rapidly, and the development stages can be mentored easily by a stereomicroscope. Due to its various advantages, zebrafish has been preferred in neuroscience, cancer, pharmacology and toxicity research for years. Recently, it has begun to be used as a model organism in dental research. This review aims to provide information on the use of zebrafish in many fields of dental research, dental materials and tooth formation.

Introduction: Zebrafish (Danio rerio) has become the best model organism to study the evolutionary biological process and human developmental studies. The liver glycogen plays a vital role in maintaining cellular metabolism, accumulation of glycogen in liver affects the enzymes related to glycogen metabolism. Aim: Impact of intermittent fasting, refeed and overfeeding in glycogen homeostasis on Zebrafish (Danio rerio) and their F1 generation. Materials and Methods: The present in-vivo study demonstrates the effect of intermittent fasting on glycogen storage in zebrafish and their F1 generation. The study was conducted at Department of Biochemistry and Biotechnology, Annamalai University, Chidambaram, Tamil Nadu, India. The duration of study was carried out for one month (December, 2021) for both parental and their F1 generation (April, 2022) groups. The F1 generation fishes involved after its matured (three months). The zebrafish (AB strain) were randomised and split into five experimental groups such as control, overfed, 12 hours, 24 hours, and 48 hours intermittent fasting. The F1 generation from each group was treated as same as parenting groups. The physiological and histological changes were observed in the study group. Significant results were evaluated as p&lt;0.05 values turkey’s method was used. Results: The fasting and overfeeding significantly affects the physiological condition like body weight, length and Body Mass Index (BMI). The parental control and their F1 have a BMI of 0.042±0.04 g/ cm² and 0.041±0.04 g/cm². The maximum fasting treated groups (48 hours) of both parent and their F1 generation shows reduced BMI such as 0.032±0.03 g/cm² and 0.030±0.04 g/cm². The over feed group shows a BMI of 0.053±0.05 g/cm² and 0.052±0.05 g/ cm². The result demonstrates that the food-deprived groups and their F1 generation showed less glycogen storage in histological observation. The reefed and overfed groups and their F1 generation exhibit more glycogen accumulation in the liver. The result confers normal regulation of glycogen synthase and glycogen synthase kinase 3 in normally in control and fasting groups as well as in their F1 generation. Conversely, the overfeeding and refeed groups show modulated glycogen activity in both parent and their F1 generation. Conclusion: Glycogen accumulation leads too many diseases and it also affects the generations. The frequent fasting may help to minimise glycogen accumulation and BMI level reduces the complications of disorders related to glycogen homeostasis.

Long-term effects of a binary mixture of perfluorooctane sulfonate (PFOS) and bisphenol A (BPA) in zebrafish (Danio rerio)

Zebrafish (Danio rerio) is an ideal model organism for the study of vertebrate development. This is due to the large clutches that each couple produces, with up to 200 embryos every 7 days, and to the fact that the embryos and larvae are small, transparent and undergo rapid external development. Using scientific literature research tools available online and the keywords Zebrafish, biomedical research, human disease, and drug screening, we reviewed original studies and reviews indexed in PubMed. In this review we summarized work conducted with this model for the advancement of our knowledge related to several human diseases. We also focused on the biomedical research being performed in Portugal with the zebrafish model. Powerful live imaging and genetic tools are currently available for zebrafish making it a valuable model in biomedical research. The combination of these properties with the optimization of automated systems for drug screening has transformed the zebrafish into "a top model" in biomedical research, drug discovery and toxicity testing. Furthermore, with the optimization of xenografts technology it will be possible to use zebrafish to aide in the choice of the best therapy for each patient. Zebrafish is an excellent model organism in biomedical research, drug development and in clinical therapy.

The primary pathological hallmark of Parkinson disease (PD) is the profound loss of dopaminergic neurons in the substantia nigra pars compacta. To facilitate the understanding of the underling mechanism of PD, several zebrafish PD models have been generated to recapitulate the characteristics of dopaminergic (DA) neuron loss. In zebrafish studies, tyrosine hydroxylase 1 (th1) has been frequently used as a molecular marker of DA neurons. However, th1 also labels norepinephrine and epinephrine neurons. Recently, a homologue of th1, named tyrosine hydroxylase 2 (th2), was identified based on the sequence homology and subsequently used as a novel marker of DA neurons. In this study, we present evidence that th2 co-localizes with serotonin in the ventral diencephalon and caudal hypothalamus in zebrafish embryos. In addition, knockdown of th2 reduces the level of serotonin in the corresponding th2-positive neurons. This phenotype can be rescued by both zebrafish th2 and mouse tryptophan hydroxylase 1 (Tph1) mRNA as well as by 5-hydroxytryptophan, the product of tryptophan hydroxylase. Moreover, the purified Th2 protein has tryptophan hydroxylase activity comparable with that of the mouse TPH1 protein in vitro. Based on these in vivo and in vitro results, we conclude that th2 is a gene encoding for tryptophan hydroxylase and should be used as a marker gene of serotonergic neurons.

To date, it is unclear whether adverse effects by genotoxic anthropogenic pollutants in the aquatic environment are linked to the decline of fish populations observed in European and North American freshwaters. Therefore, there is a need for investigations into the relationship between genotoxic stress and detrimental effects on development and reproduction in fish. In order to contribute to this field, the present thesis investigates effects of the alkylating genotoxin methyl methanesulfonate (MMS) on genetic integrity, histological status and reproduction in zebrafish (Danio rerio). In addition, in their unexposed offspring (F1), larval development, histological status and reproduction as well as development in the F2 generation were examined at the population level in order to identify potential inheritable effects of genotoxicity. First, methods for the use of primary gonad cells from zebrafish in the alkaline comet assay and histological sections of testis and ovary in the micronucleus test were developed. After in vivo exposure of adult zebrafish to MMS for up to two weeks, in the comet assay, concentrations-dependent genotoxic effects were detected in gonads, liver and gills. Likewise, the micronucleus frequency was elevated by MMS in all of these organs. Thus, the concentration range adequate for MMS exposure in the designated multi-generation experiment was identified. In the next step, zebrafish (F0) were exposed to MMS in vivo from fertilization until the age of one year. Mortality of F0 fish clearly depended on MMS concentrations. In exposed fish, times of first spawning were delayed and fertility was reduced. However, no unequivocal effects on growth were found. In F1 fish derived from MMS-exposed fish, teratogenic effects were increased, larval survival was reduced and sex ratio was shifted towards females. However, compared to the exposed F0 generation, fertility of the non-exposed F1 generation recovered. Development and survival rates recovered in the F2 generation. Significant genotoxic effects were found in the livers, gills and gonads of either sex of the F0 generation. Regarding histopathological aberrations and external lesions, mainly malformations of eyes, gills and liver and a number of neoplasia were observed in both the F0 and F1 generation. According to indirect measurement of MMS concentrations using ion chromatography, real concentrations in the replicate tanks were similar. Taken together, chronic exposure of zebrafish to MMS led to DNA damage in somatic and generative tissues, induced the formation of a multitude of histopathological aberrations and affected survival, reproduction and development in exposed fish and their offspring. Regarding several endpoints, cessation of exposure allowed for recover over the generations. Combining these results with data of previous studies and transferring them to the environmental situation, there is considerable evidence that anthropogenic genotoxicants play a role in the decline of wild fish populations.

Chronic toxicity of diethyl phthalate—A three generation lactational and gestational exposure study on male Wistar rats

OATP2B1 belongs to a highly conserved organic anion transporting polypeptide (OATP) family of transporters, involved in the cellular uptake of both endogenous and exogenous compounds. The reported substrates of human OATP2B1 include steroid conjugates, bile salts, and thyroid hormones, as well as pharmaceuticals. Human OATP2B1 has orthologous genes in other vertebrate species, including zebrafish (Danio rerio), a widely used model organism in biomedical and environmental research. Our previous studies showed that zebrafish Oatp2b1 was phylogenetically closest to mammalian OATP2B1/Oatp2b1 and that it shares a similar tissue expression pattern. In this study, we aimed at discovering whether zebrafish Oatp2b1 could be a functional ortholog of human and rodent OATP2B1. To test this hypothesis, our primary goal was to obtain the first in vitro and in silico insights related to the structure and potential substrate preferences of zebrafish Oatp2b1. We generated cells transiently and stably transfected with zebrafish Oatp2b1 cloned from zebrafish liver, constructed an Oatp2b1 homology model, developed transport activity assays with model fluorescent substrate Lucifer yellow, and finally utilized this assay to analyze the interaction of zebrafish Oatp2b1 with both physiological and xenobiotic substances. Apart from structure similarities, our data revealed the strongest interaction of zebrafish Oatp2b1 with bile acids, steroid sulfates, thyroid hormones, and bilirubin, as well as xenobiotics bromosulfophthalein and sulfasalazine, which indicates its functional orthology with human OATP2B1.

Biomedical research requires suitable model organisms to be able to understand the pathogenesis of disease at the cellular and molecular level and the suitability of systems for the development and testing of new therapies. The choice of model organisms for biomedical research depends very much on the research objectives. Basically, the selection of model organisms is based on several aspects, namely: biological, technical and historical aspects. The general criteria for selecting model organisms are: small size, fast reproduction time, low and easy maintenance, easy experimental techniques, complete basic information. The development of research using animal models further leads to the level of genetic functional conservation in the basic processes of cell biology between mammals and invertebrates such as fruit flies (Drosophila melanogaster) and nematode worms (Caenorhabditis elegans). However, there are significant limitations between mammals and invertebrates, among others due to differences in organ systems and their development, so now widely used zebra fish (Danio rerio) as model organisms that bridge between invertebrates and vertebrates. In addition to these reasons there are several other scientific reasons that make zebra fish a superior organism model for biomedical research, namely: having a high homology with humans (75%), transparent embryos, high levels of fecundity, fast embryogenesis, relatively fast life span , procurement and maintenance is relatively inexpensive, complete basic information and genetic information (whole genome sequencing), has a cardiovascular system, nerves, immune system and digestive system similar to mammals, sensitive to environmental changes so that many bio-indicators are used for toxicity testing and testing and development drug.

Tilapia chromosomal growth hormone gene expression accelerates growth in transgenic zebrafish (Danio rerio)

The zebra fish (Danio rerio) is widely recognized as a prominent model organism in research. In contrast, Indonesia, with its abundant aquatic resources, frequently encounters the guppy (Poecilia reticulata) in its freshwater ecosystems. Notably, guppies exhibit reproductive rates akin to those of zebra fish. This study endeavors to compare the histomorphometric characteristics of the liver and intestinal organs between zebra fish and guppies. The research involved 9 zebra fish and 9 guppies obtained from local breeders in Malang, East Java. Following euthanasia, histological samples were prepared through a series of procedures including fixation, trimming, dehydration, clearing, paraffin embedding, sectioning, Hematoxylin-Eosin staining, and mounting. Histomorphometric observations focused on the diameter and area of hepatocytes, as well as the height and width of intestinal villi. The data were analyzed quantitatively using an Independent Sample T-Test at a 95% confidence level, facilitated by SPSS (Statistical Package for the Social Sciences). The findings revealed statistically significant differences in the histomorphometry of hepatocyte diameter and area, as well as the height and width of intestinal villi between zebra fish and guppies, with a significance value (2-tailed) of &lt;0.05. These differences are attributed to various factors, including habitat, dietary selection and frequency, and physiological adaptations to the environmental conditions of the two species. The findings also contributed to novel insight utilizing these fish to be animal models that guppy fish is more suitable for aquaculture research model and zebra fish likely to more appropriate in human model.

Quantitative GFP fluorescence as an indicator of arsenite developmental toxicity in mosaic heat shock protein 70 transgenic zebrafish