part 246,
august 2020
, 110705
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Abstract
Current techniques for determining heart rate in adult zebrafish require experience and are often invasive, technically demanding and not easily transferable to other laboratories for routine testing. Here we present a simple, non-invasive and inexpensive lightcardiogram technique to assess heart rate and heart rate in adult zebrafish. Brightfield microscope in combination with a high resolution camera and ImageJ (an open source software) were used as central acquisition and processing platforms, respectively. The heart was visualized and located ventrally by juxtaposing an isosceles triangle between the operculae as a reference to analyze the pixel intensity fluctuations generated by each cardiac cycle to derive heart rate and rate. Compared to transparent embryos, the cardiograms generated inverse oscillations of the light signal, with contraction and relaxation of the heart (ventricle) corresponding to decrease and increase in pixel intensity, respectively. Heart rates (♂ 122.58 ± 2.15 and ♀ 121.37 ± 2.63 beats/min) and mean dominant frequency (♂ 2.04 ± 0.035 and ♀ 2.05 ± 0.048 Hz) between genders did not were significant (P>.05) different at 28°C. However, theDThe amplitudes between men (0.26 ± 0.03) and women (0.45 ± 0.05) were significantly different (P<0.05) indicates gender-specific diastolic cardiac output. Overall, the technique can be used to measure heart rates, but it can also be easily adapted to record relative cardiac output and compare differences between physiological states (eg, gender). Furthermore, the approach can be automated and applicable to other fish species, giving researchers the flexibility to measure these and other critical heart health parameters with relative ease.
introduction
from zebravis (denmark rerio) has emerged as an excellent vertebrate model for cardiovascular research. Despite having only one atrium and one ventricle (i.e. anatomically distinct), the electrophysiology of the zebrafish heart is remarkably conserved (Liu et al., 2016) with many key functions similar to those of the human heart (Nemtsas et al. ., 2010; Zhang et al., 2018). For example, spontaneous heartbeats are comparable to those of humans (Stainier, 2001).
Optically transparent zebrafish embryos are used to study cardiac development (Bakkers, 2011; Brown et al., 2016), physiology (Hoage et al., 2012; Yalcin et al., 2017) and associated human congenital diseases (Asnani and Peterson, 2014). ; Giardoglou and Beis, 2019). Typically, brightfield video digital motion analysis is used to determine cardiac functions such as heart rate and rate (Hoage et al., 2012; Gieren et al., 2020). As a result, researchers can now record and process thousands of videos simultaneously to analyze fluctuations in pixel intensity generated by each cardiac cycle of zebrafish embryos (Martin et al., 2019; Gieren et al., 2020). However, embryonic zebrafish transparency is gradually lost with age and effective tools for cardiac phenotyping are lacking for later stages of development, particularly in juvenile and adult animals (Zhang et al., 2018). An exception to this is a transgenic zebrafish strain that expresses red fluorescence in vessel walls (Littleton et al., 2013), transparent adult zebrafish (White et al., 2008), and the use of Eulerian video magnification. (Lauridsen et al., 2019). ). However, these are limited in terms of payload, relatively expensive and require specialist knowledge.
In mammalian models, cardiac function is usually assessed by echocardiography (Locatelli et al., 2011; Abduch et al., 2014). However, due to the small size of juvenile and adult zebrafish hearts (~0.25 and 1 mm in diameter, respectively), the resolution of classical low-frequency ultrasound is not satisfactory (Hoage et al., 2012; Wang et al., 2017). Recently, high-frequency echocardiography (HFE) allowed the study of heart rate in adult zebrafish (≥20 mm in length) (Liu et al., 2016; Wang et al., 2017; Zhang et al., 2018; Evangelisti et al., 2017; al., 2020) with acceptable image quality only for larger and older fish (6-9 months) (Wang et al., 2017). Furthermore, the HFE image quality of female zebrafish was impaired compared to males due to female attraction (Wang et al., 2017).
A simplified electrocardiogram (ECG) has also been used to study heart rate in zebrafish adults (Milan et al., 2006; Yu et al., 2010; Lin et al., 2018) and larvae (Dhillon et al., 2013 ) with an ECG profile fundamentally similar to humans (Milan et al., 2006; Liu et al., 2016). However, HFE and ECG techniques require expertise (Lin et al., 2018) and are often invasive. For example, ECG requires the implantation of an array of microelectrodes in direct contact with the epicardium (Cao et al., 2014; Liu et al., 2016; Lin et al., 2018), using an in vitro recording of the explanted heart (Yu et al., 2010; Tsai et al., 2011; Zhang et al., 2018) or the placement of specialized electrodes (Marchant and Farrell, 2019), all of which require specialized and often complicated micromanipulation. The ECG can also be affected by various sources of noise, such as: B. Power cord artifacts, electrode contact noise and muscle movements (Liu et al., 2016). ECG and HFE also require a complex and expensive software-hardware combination that is unusual, well-integrated, and easily transferable to other laboratories (Liu et al., 2016; Zhang et al., 2018; Martin et al., 2019).
Until now, brightfield imaging to study heart rate in zebrafish has been limited to optically transparent embryos and larvae. However, based on visual (ventral) observations, we hypothesize that the heart may emit fluctuating pixel intensities on the ventral surface of the fish skin that are synchronized with its beats. Therefore, this study aimed to develop a simple light imaging method to assess heart rate and heart rate in adult zebrafish.
fragments section
Of Dreams
All animal testing has been approved by the University of Tasmania Animal Ethics Committee (A12787). Adult zebrafish were maintained in a continuous flow system with a light:dark photoperiod of 12:12 hours at 28°C (7 fish per 30 liters) and fed twice a day. Feeding was interrupted six hours before the experiments.
Determining the optimal anesthesia
A preliminary test was carried out to determine the optimal duration and concentration of the AQUI-S® anesthetic. Adult (N= 10/treatment; CT = 35.5 ± 1.5 mm; eight months).
A low dose of AQUI-S® maintains a stable heart rate
Adequate sedation to immobilize the zebrafish is required to record cardiovascular data (Liu et al., 2016; Lin et al., 2018). Prior to the LCG assessment, we tested AQUI-S® as an alternative sedative to tricaine (MS-222) due to the latter's negative chronotropic effects (Huang et al., 2010; Liu et al., 2016). There were progressive cuts (P> 0.05) in HR from 1 to 6 min of exposure to 6 ppm AQUI-S® (Table 1). However, at 3 ppm there was no significant reduction in HR or HF compared to
Diploma
We developed a semi-automated, simple and non-invasive approach for CF and FDof adult zebrafish with brightfield images that can be easily adopted by any laboratory. This study offers the opportunity to comparatively examine cardiovascular function across all life stages of zebrafish and can be easily adapted to other fish species and for automation.
financing
This work was supported byAustralian Research Council(THE BOOKLP140100428).
Declaration of competitive interest
The authors declare no conflicts of interest.
recognition
Comments on earlier drafts of the manuscript by Nicholas Perkins (IMAS, University of Tasmania) and two anonymous reviewers significantly improved the manuscript.
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5-HMF influences cardiovascular development in zebrafish larvae through reactive oxygen species and Wnt signaling
2022, Comparative Volume of Biochemistry and Physiology - C: Toxicology and Pharmacology
Quote excerpt:
In this study, observations and statistics after treatment of zebrafish embryos with different concentrations of 5-HMF showed that the heart rate and pericardial edema rate of the treatment groups increased. Heart rate is the most intuitive data to illustrate cardiac muscle development (Mousavi and Patil, 2020) and this study indicated that 5-HMF has apparent toxicity to the zebrafish heart. Furthermore, apoptotic cells in the pericardial region and expression of pro-apoptotic genes (bax and p53) were significantly increased in the 5-HMF-treated group compared to the control group.
5-Hydroxymethylfurfural (5-HMF) is a low molecular weight aldehyde produced by the Maillard reaction. Because 5-HMF is found in a variety of foods and drugs and is easily ingested by humans, it has attracted a great deal of toxicological attention in recent years. Relevant studies have shown that 5-HMF has cytotoxicity, genotoxicity and tumor effects. However, the cardiovascular effects of 5-HMF are unknown. To study the cardiovascular effects of 5-HMF in zebrafish, wild-type and transgenic embryos were treated with 10, 25 and 50 μg/ml of 5-HMF, followed by toxicological evaluation, histological observation, fluorescence observation, cellular apoptosis and quantitative gene analysis. High concentrations of 5-HMF resulted in a significant increase in heart rate and pericardial edema rate, increased distance between the sinus venosus and the bulbus arteriosus, increased cardiac cell apoptosis, cardiac linearization, defects in angiogenesis and cardiovascular development and apoptosis-related gene expression disorders in zebrafish larvae. Abnormal phenotype caused by 5-HMF can be rescued by antioxidantsN-Acetyl-L-Cysteine (NAC) and Wnt pathway activator BML-284. It is concluded that high concentrations of 5-HMF increased levels of reactive oxygen species, inhibited transduction of the Wnt signaling pathway and led to abnormal cardiovascular development in zebrafish larvae. This study provides a framework for understanding the mechanism of 5-HMF's effects on cardiac development.
Evaluation of the toxicity of bisphenol A and its six alternatives in zebrafish embryos/larvae
2022, Aquatic Toxicology
Quote excerpt:
(Video) Dr. Thao Nguyen: Fishing for Insights from Single-Lead and Multi-Lead ECG of Live Adult ZebrafishBPF significantly reduced spontaneous movements at LC50 concentrations of 5% and 25% (1.25 and 6.25 mg/L) and BPAP significantly reduced spontaneous movements at LC50 concentrations of 25% and 50% (0.25 and 0.5 mg/L). Zebrafish are an excellent vertebrate model for cardiovascular research, as their spontaneous heart rate is similar to that of humans (Mousavi et al., 2020). BPB, BPC, BPE and BPF significantly reduced the heart rate of zebrafish embryos at concentrations of 25% and 50% LC50 (Figure 2b).
Bisphenol A (BPA) analogues are gradually replacing BPA in the plastics industry. However, it remains unclear whether these alternatives are actually safer than BPA itself. Here we examine the toxicity of BPA and six of its alternatives - BPB, BPC, BPE, BPF, BPAF and BPAP - using zebrafish embryos/larvae. According to its semi-lethal concentration (LC50), the acute toxicity of BPA and six alternative bisphenols to zebrafish embryos from highest to lowest was BPAP ≈ BPAF > BPC > BPB > BPA > BPE > BPF. At non-lethal concentrations, the tested bisphenols had various developmental toxic effects in terms of reducing hatching rate, frequency of spontaneous movement and heart rate in the embryo, and inducing yolk sac edema, pericardial edema and spinal deformity in the larvae. . The estrogenic activity of BPE, BPF and BPAF was higher than that of BPA, as demonstrated byvtg1expression tests. Furthermore, BPA and its alternatives increased SOD activity and cell apoptosis in embryos/larvae at non-lethal concentrations. Our results indicate that BPA alternatives may not be safer than BPA in zebrafish and that these BPA alternatives should be used with caution.
Quantitative measurements of heart rate and heart rate variability in zebrafish: a study between 1990 and 2020
2022, Computers in Biology and Medicine
Quote excerpt:
Mousavi et al. (2020) used light cardiogram techniques and ImageJ as their main assessment tools to analyze changes in intensity according to heart rhythm and then generate HR and rate data. His non-invasive and inexpensive technique can measure heart rate in zebrafish and other fish species [42]. Gieren et al (2020) developed a high-throughput automated software package for the quantification of zebrafish embryo RH, allowing batch screening of zebrafish in microtiter plates [43].
Because of its advantages of rapid proliferation and high gene homology to humans, the zebrafish is an essential model organism for the study of cardiovascular disease. Zebrafish embryos/larvae are valuable experimental models used in toxicology studies for drug toxicity analysis including hepatotoxicity, nephrotoxicity, and cardiotoxicity, as well as for drug discovery and preclinical drug safety screening. Heart rate (HR) serves as a functional endpoint in cardiotoxicity studies, while heart rate variability (HRV) serves as an indicator of cardiac arrhythmias. Cardiotoxicity is a major cause of early and late terminations of drug studies, so a better understanding of zebrafish HR and HRV is important. This review has summarized HR and HRV into a specific set of applications and areas, focusing on zebrafish heart rate detection techniques, signal analysis technology, and established commercial software such as LabVIEW, Rvlpulse, and ZebraLab. We also compare HR detection algorithms and electrocardiography (ECG)-based methods for extracting cardiac signals. The connection between HR and HRV was also analyzed systematically; It was found that HR has an inverse correlation with HRV. Drug testing applications are also highlighted in this overview. Furthermore, it was found that HR and HRV are regulated by the automatic nervous system; its connections to ECG measurements are also summarized here.
Assessment of developmental toxicity of Drymaria Cordata (Linn.) Willd using zebrafish embryos
2023, current drug safety
Selected Items (6)
Research Article
Mechanisms regulating the abnormal expression of miR-96 and miR-184 in the development of optic vesicles in zebrafish after exposure to β-diketone antibiotics
Chemosphere, Band 214, 2019, S. 228-238
Chronic ototoxicity of β-diketone antibiotics(DKAs) for zebrafish (denmark rerio) was studied in detail by monitoring abnormal expressions of two hearing-related miRNAs. A dose-dependent down-regulation of miR-96 and miR-184 was observed in otoliths during embryonic larval development. Continuous CAD exposure to 120 pkf larvae reduced sensitivity to acoustic stimulation. Otolith development was delayed in treatment groups, showing blurred borders and vacuolation at 72 hpf and utricular enlargement and reduced saccular volume at 96 hpf or posterior larval otoliths. When one miRNA was degraded and another overexpressed, this had little effect on the morphological development of otic vesicles, but a precipitated or overexpressed miRNA significantly affected normal zebrafish development. Injection of miR-96, miR-184 or both mimic miRNAs into the yolk sac resulted in a marked improvement in the ear vesicle phenotype. However, hair cell staining showed that only the injected miR-96 mimics regained hair cell numbers after exposure to CAD, demonstrating that miR-96 played an important role in the development of otic vesicles and auditory formation, while miR-184 was involved only in otic vesicles. Structure during embryonic development. These observations advance our understanding of hearing loss due to acute antibiotic exposure and provide theoretical guidelines for early intervention and gene therapy in drug-induced disease.
Research Article
Differential effects of bisphenol a and its halogenated derivatives on reproduction and development of Oryzias melastigma at environmentally relevant doses
Total Environmental Science, Band 595, 2017, S. 752-758
(Video) Understanding Zebrafish Heart Function - Understand the Development of the Human HearthBisphenol A (BPA) and its halogenated compounds (H-BPAs) are widely detected in environmental media and organisms. However, their toxicological effects, especially with chronic low-dose exposure, have not been fully compared. In this study, the effects of BPA and H-BPA on the reproduction and development ofOryzia melastigmawere systematically evaluated and compared at various stages of development. BPA and its derivatives tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA) caused the acceleration of embryonic heart rate. BPA had no significant effect on the time and rate of embryo hatching. In contrast, both TBBPA and TCBPA resulted in delayed hatching and reduced results. Consequently, expression of the hatching enzyme significantly decreased after exposure and TCBPA was found to be more toxic than TBBPA. The body weight and gonadsomatic index (GSI) of the treated fish were relatively lower than those of the control fish with longer exposure (four months from larval to adult) to BPA rather than H-BPAs. Delay in oocyte development occurred in the ovaries and estrogen levels decreased after exposure to BPA instead of H-BPAs. No significant changes in testes were observed in male fish for any group. Testosterone concentration significantly decreased when exposed to BPA instead of H-BPAs. The effects of these three chemicals on estrogen-related gene expression were different at different stages of development. Our study showed the importance of considering both exposure levels and the structure-activity relationship when assessing the ecotoxicological effects of pollutants.
Research Article
Early safety assessment of human oculotoxic drugs using zebrafish visual motor response
Journal of Pharmacological and Toxicological Methods, Band 69, Ausgabe 1, 2014, S. 1-8
Many prescription drugs can affect the eye by impairing the functioning of the visual pathways or damaging the retina. Zebrafish have the potential to efficiently predict drugs with adverse effects on the eye in preclinical stages of development. In this study, we investigated the potential of using a semi-automated visual behavioral test to predict drug-induced ocular toxicity in wild-type zebrafish larvae.
3dpf larvae were treated with six known oculotoxic drugs and five control drugs in embryo medium containing 0.1% DMSO. After 48 hours, larvae were scored using visuomotor response (VMR), an assay that quantifies locomotor responses to changes in light; the optokinetic response (OKR), a behavioral test that quantifies ocular saccadic responses to rotational stimuli; and the touch response, a locomotor response to tactile stimuli.
9 out of 10 negative control drugs had no effect on zebrafish vision. 5 out of 6 known oculotoxic drugs (digoxin, gentamicin, ibuprofen, minoxidil and quinine) showed adverse effects on zebrafish visual behavior as assessed by OKR or the more automated VMR. No gross morphological changes were observed in the treated larvae. The general locomotor activity of treated larvae tested using the touch response assay showed no differences from controls. Overall, the VMR assay had a sensitivity of 83%, a specificity of 100%, and a positive predictive value of 100%.
This study confirms the suitability of the VMR assay as an efficient and predictive preclinical approach to assess adverse ocular drug effects on visual function in vivo.
Research Article
Distinguish the mechanism of action of compounds that induce craniofacial malformations in zebrafish embryos to aid in dose-response modeling at combined exposures
Reproductive Toxicology, Vol. 96, 2020, pp. 114-127
Knowledge of the Mechanism of Action (MOA) is necessary to understand the toxicological effects of compounds, especially in the context of risk assessment of mixtures. This information is often sparse and often complicated by the presence of multiple MOAs per connection. Here, MOAs related to developmental craniofacial malformations were extracted from the literature and collected in a MOA network. A selection of gene expression markers was based on these MOAs. Subsequently, these markers were verified by qPCR in zebrafish embryos after exposure to reference compounds. They were: triazoles to inhibit retinoic acid (RA) metabolism, AM580 and CD3254 to selectively activate the RA receptor (RAR) and retinoid X receptor (RXR), respectively, dithiocarbamates to inhibit lysyl oxidase, TCDD to activate the receptor aryl carbohydrate (AhR ), VPA to inhibit histone deacetylase (HDAC) and PFOS to activate peroxisome proliferator activated receptor alpha (PPARα). Marker gene profiles for these reference compounds were then used to match profiles of test compounds with known MOAs. Thus, 2,4-dinitrophenol was consistent with the TCDD and RAR profiles, boric acid with RAR, endosulfan with PFOS, fenpropimorph with dithiocarbamates, PCB126 with AhR, and RA with triazoles and RAR profiles. Prochloraz did not show agreement. Activities of these compounds in ToxCast assays, enin siliconBinding affinity analysis for the respective targets showed limited agreement with the marker gene expression profiles, but still confirmed the complex profiles of reference MOA and test compounds. Finally, this approach can be used to support the modeling of blending effects based on known knowledge about (dis)similarity of MOAs.
Research Article
Sympathetic/beta-adrenergic pathway mediates irisin regulation of cardiac functions in zebrafish
Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology, Volume 259, 2021, Item 111016
Irisin is a 23 kDa myokine encoded in its precursor, the fibronectin type III domain containing 5 (FNDC5). Exercise-induced increase in expression of peroxisome proliferator-activated receptor gamma-coactivator 1-alpha (PGC1-α) promotes FNDC5 mRNA, followed by proteolytic cleavage of FNDC5 to release irisin from skeletal or cardiac muscle into the blood. Irisin is abundantly expressed in skeletal and cardiac muscle and plays an important role in food intake, modulates appetite-regulating peptides, and regulates cardiovascular functions in zebrafish. In this study, to determine possible mechanisms of the acute effects of irisin, we investigated whether adrenergic or muscarinic pathways mediate the cardiovascular effects of irisin. Propranolol alone (100 ng/g bw) modulated cardiac function and when injected in combination with irisin (0.1 ng/g bw) attenuated the effect of irisin on the regulation of cardiovascular function in zebrafish 15 minutes after injection. Atropine (100 ng/g B·W) modulated cardiovascular physiology in the absence of irisin, being ineffective in influencing irisin-induced effects on cardiovascular function in zebrafish. One hour after injection, irisin reduced the expression of PGC-1 alpha, myostatin a and myostatin b mRNA in zebrafish heart and skeletal muscle. Propranolol alone had no effect on the expression of these mRNAs in zebrafish and did not alter irisin-induced changes in expression. 1 hour after injection, irisin siRNA decreased PGC-1 alpha, troponin C, and troponin T2D mRNA expression, while increasing myostatin a and b mRNA expression in zebrafish heart and skeletal muscle. Atropine alone had no effect on mRNA expression and was unable to alter the effects on siRNA mRNA expression. Overall, this study identified a role for sympathetic/beta-adrenergic signaling in regulating the effects of irisin on cardiovascular physiology and cardiac gene expression in zebrafish.
Research Article
Developmental toxicity of dibutyl phthalate and citrate ester plasticizers in Xenopus laevis embryos
Chemosphere, Banda 204, 2018, S. 523-534
Citrate esters have been considered as alternatives to phthalate plasticizers. Because they are considered of low toxicity to mammals, their aquatic toxicological information is still little known. We evaluated the developmental toxicity of citrate esters, including tributyl O-acetyl citrate (ATBC), triethyl 2-acetyl citrate (ATEC) and trihexyl O-acetyl citrate (ATHC) together with dibutyl phthalate (DBP) based on the assay of Toad embryonic teratogenesis.Xenopus(FETAX). ATBC has the shortest 96-hour LC50in 96u EG50Values. In RT-qPCR, the proportion ofbaxEmbcl-2mRNA was significantly increased by DBP but not by ATBC, ATEC and ATHC. DNA fragmentation was evident in DBP-treated tadpoles, but not in those treated with ATBC and ATEC, while ATHC caused necrotic DNA degradation. Lipid hydroperoxide levels in tadpoles were significantly increased by DBP and ATHC, but not by ATBC and ATEC, suggesting the induction of oxidative stress by DBP and ATHC in embryos. In tadpoles with head defects, basihyalism, ceratohyal bone and Meckel's cartilage were often overlooked along with gill bone reduction.Col2a1The mRNA in the head of tadpoles was significantly reduced by low concentrations of DBP, ATHC and high concentrations of ATEC. Embryos at stage 25VosN3mRNA, a key regulator of neural crest cell-head chondrocyte differentiation, was significantly reduced by DBP and ATHC, but not by ATBC and ATEC. In conclusion, ATEC was recommended as an alternative to phthalate plasticizers with the lowest developmental toxicity in amphibian embryos.
(Video) HFUS Echocardiography for Cardiac Function Assessment | Protocol Preview
Crown Copyright © 2020 Published by Elsevier Inc. All rights reserved.
FAQs
What is the normal heart rate of a zebra fish? ›
In zebrafish, the normal embryonic heart rate is much closer to that of humans, at 120–180 beats per minute32.
What is the cardiac output of zebrafish? ›Key findings: Cardiac output (CO) in PHZ-treated zebrafish was significantly higher than that in control zebrafish (151 ± 67 vs. 84 ± 37 μl/min, P = 0.004), whereas ejection fraction (EF) was lower (36.3 ± 10.9 vs.
Do zebrafish have a heart? ›The zebrafish adult heart has one atrium and one ventricle; it is smaller and simpler than the mammalian heart but the histological and structural composition is very similar to that of other vertebrates.
How many times does a zebrafish heart beat per minute? ›Similarly, after onset of heartbeat in zebrafish, heart rate increased and plateaued at around 210 bpm (28 °C, 72 hpf; Fig. 4b). Zebrafish heart rate did not exhibit a day-night dependent fluctuation during the period of analysis (22–62 hpf). Heart rates of medaka and zebrafish during embryonic development.
How many times does a zebra heart beat per minute? ›Evaluation of ECGs from 19 zebras revealed sinus rhythm with a predominantly negative QRS complex and a mean +/- SD heart rate of 67 +/- 10 beats/min.
Why do cardiologists study zebrafish? ›The zebrafish as a model organism
Unlike humans, zebrafish can regenerate new cardiac tissue after an injury such as a heart attack, which makes them a great model to study the cellular and molecular mechanisms involved in cardiac regeneration.
The Zebrafish adult heart is not the same as the human heart as it has a simpler structure, but it is similar enough to replicate cardiovascular function. It only has a single atrium and ventricle (which contains two kinds of cardiac muscle), but these work in an equivalent way to those of a human heart.
Why might cardiologists find it useful to study zebrafish? ›Zebrafish embryos are transparent, making it easy to spot abnormalities. Particularly helpful for cardiology research: mutant embryos lacking active circulation are capable of surviving up to 5 days post fertilization. And zebrafish hearts are simpler than mammals': theirs have just two chambers, while ours have four.
What is unique about zebrafish? ›Because of its fully sequenced genome, easy genetic manipulation, high fecundity, external fertilization and rapid development, and nearly transparent embryo, zebrafish are a unique model animal for biomedical research, including studies of biological processes and human diseases.
What is special about zebrafish? ›One important advantage of zebrafish is that the adults are small and prefer to be housed in large groups, or “shoals”. As a result, they require much less space and are cheaper to maintain than mice. The NIH Zebrafish Core houses hundreds of thousands of zebrafish in a state-of-the-art facility.
What is the structure of the zebrafish heart? ›
Zebrafish have a prototypic heart with only one ventricle and one atrium.
How do you calculate animal heart rate? ›Your pet should be calm and quiet. Place your hand over this area of the chest and feel for a heartbeat. You can also use a stethoscope if you have one. Count the number of heartbeats for 15 seconds and multiply that number by 4.
What species has the fastest heartbeat? ›The heart of the Etruscan shrew, one of the world's smallest mammals, beats incredibly fast — up to 1,500 times per minute, or 25 times per second. The human heart, in comparison, is sluggish, beating only 60 to 100 times a minute. Then there's the heart of the blue whale, the largest animal ever to have lived.
What bird has the fastest heartbeat? ›How fast does a hummingbird's heart beat? Their hearts can beat as fast as 1,260 beats per minute, which is the rate measured in a Blue- throated Hummingbird, or as slow as 50-180 beats per minute on a cold night when they experience torpor, a hibernation-like state.
How fast does a zebra run per hour? ›Zebras are equids, members of the horse family. They have excellent hearing and eyesight and can run at speeds of up to 35 miles per hour (56 kilometers per hour).
Which animal heart beats 1000 times per minute? ›An adult human resting heart rate is normally 60 to 100 beats per minute, while shrews clock in at “over 1,000 beats per minute—that's over 16 times a second,” Mark Oyama, cardiology professor at the University of Pennsylvania School of Veterinary Medicine, says via email.
What animal has the lowest heart rate per minute? ›The largest mammal, the blue whale, has a heart the size of a sofa, and their heart beats have been recorded as low as two per minute. That's the slowest heartbeat of any warm blooded mammal.
What is the zebrafish in the study of early cardiac development? ›The zebrafish has emerged as a powerful model system to unravel the basic genetic, molecular, and cellular mechanisms of cardiac development and function. We summarize and discuss recent discoveries on early cardiac specification and the identification of the second heart field in zebrafish.
What do scientists use zebrafish to study? ›Since the 1970s, zebrafish have been used to study a variety of human diseases, including cancer, cardiovascular disease, and diabetes.
What is the main advantage of using the zebrafish embryos for this type of study? ›The zebrafish model has significantly improved our ability to study vertebrate developmental biology. The strengths of this model system lie in its external, visually accessible development, ease of experimental manipulation, and common genetic underpinnings with other vertebrates including humans.
Do zebrafish have a four chambered heart? ›
Unlike mammals, which have four chambers, the zebrafish heart consists of only two: a single ventricle (left) and a single atrium (right). Despite the difference in the number of chambers, the heart is the first organ to form in both mammals and zebrafish.
Why is the fish heart different from the human heart? ›Unlike humans, they have a single circulatory pattern. Fish have a simple circulatory system, which consists of a two-chambered heart, blood, and blood vessels. Unlike humans, they have a single circulatory pattern.
How does the zebrafish heart regenerate? ›Regeneration of the zebrafish heart
By 7dpa, the wound is sealed by fibrin and is replaced by cardiac muscle by 30 dpa. (b) Proliferation, based on BrdU incorporation, is activated in cardiomyocytes by 7 dpa. The ventricular wall is restored by proliferation at the leading edge of the regenerating tissue.
Because of its fully sequenced genome, easy genetic manipulation, high fecundity, external fertilization and rapid development, and nearly transparent embryo, zebrafish are a unique model animal for biomedical research, including studies of biological processes and human diseases.
How zebrafish research has helped in understanding thyroid diseases? ›Zebrafish and mammals possess the same molecular mechanism of thyroid organogenesis and development. Thus, thyroid hormone signaling, embryonic development, thyroid-related disorders, and novel genes involved in early thyroid development can all be studied using zebrafish as a model.
Why are zebrafish good models to use to study human disease? ›As zebrafish eggs are fertilised and develop outside the mother's body it is an ideal model organism for studying early development. Zebrafish have a similar genetic structure to humans. They share 70 per cent of genes with us. 84 per cent of genes known to be associated with human disease have a zebrafish counterpart.
What is one advantage of using the zebrafish as a research animal? ›Similarity to humans
This tiny tropical fish contains 70% of the human genome code, meaning its organs and cells are very similar to those of humans. Moreover, zebrafish have orthologs in 82% of human disease-associated genes, making them especially translatable for genetic research.
Disadvantages: They require water systems to maintain them. They are not mammals and are not as closely related to humans as a mouse is. Reverse genetics has not been worked out for zebrafish as it has in the mouse.
What are some interesting facts about zebra Danios? ›The scientific name of zebrafish is Danio rerio and it belongs to the minnow family, Cyprinidae. The fish got its common name from the presence of five uniform and pigmented horizontal stripes on the side of its body, which resemble the stripes of a zebra.
What color do zebrafish prefer? ›Results showed that zebrafish preferred green over blue and domesticated fish chose green more than blue when there was a reward attached. Zebrafish also preferred red over green. Fish from one wild population learned with both colors and reversed learning only from green to red and not vice-versa.
What do zebrafish need? ›
To maintain zebrafish in a healthy condition, it is important to provide them with a clean environment in a properly functioning aquarium system. An important part of this is changing system filters regularly so that all the tanks receive proper water flow and clean water.
What anesthetic is most commonly used for zebrafish? ›MS-222 (tricaine methanesulfonate) is the anaesthetic that has been the most largely used by the scientific community [18].
What is the structure and function of the developing zebrafish heart? ›The zebrafish heart consists of four chambers (sinus venosus, atrium, ventricle, and bulbus arteriosus) connected in series. It pumps desaturated venous blood to the ventral aorta leading to the gill arches where oxygenation occurs, and from where it is distributed to the rest of the body.
What are the cells of zebrafish heart? ›The zebrafish heart contains the same types of cells compared to the mammalian heart, including cardiomyocytes, epicardial cells, endocardial cells, and vascular endothelial cells.
What are the features of fish heart? ›The systemic heart of fishes consists of four chambers in series, the sinus venosus, atrium, ventricle, and conus or bulbus. Valves between the chambers and contraction of all chambers except the bulbus maintain a unidirectional blood flow through the heart.
What is the respiratory rate of zebrafish? ›A typical resting ventilatory rate for adult zebrafish is approximately 160 breaths min−1; whereas hypoxia ( P O 2 of 35–40 mmHg) may elevate ventilation frequency to above 300 breaths min−1 (Jonz and Nurse, 2005, Vulesevic et al., 2006).
How many hearts does a zebrafish have? ›Zebrafish have a prototypic heart with only one ventricle and one atrium.
What is the size of zebra fish heart? ›Due to the small size of the adult zebrafish heart (about 1 mm in diameter), the resolution of classic ultrasound-based technology is not satisfactory for reliable measurements of shortening fraction.
What is the normal heart rate of a shark? ›In small, relatively inactive sharks such as the Spiny Dogfish, Lesser and Greater Spotted (Scyliorhinus stellaris) Catsharks. and the Leopard Shark (Triakis semifasciata), heart rate measures about 19 to 48 beats per minute. No one has yet managed to measure the heart rate of a White Shark.
How do you take a fish's respiratory rate? ›The mouth working in unison with the gills, moves water from the mouth over the gills to remove oxygen from the water. The respiration rate of a goldfish can be measured by counting the number of times each minute the gills and their coverings move.
What is the heart rate of zebrafish with caffeine? ›
Exposure to high concentrations of caffeine significantly decreases the heart rate32 and increases stress-sensitive cortisol levels31. Hence, given that caffeine affects the behavior and physiological state of zebrafish, it may also affect ventilation.
What is the normal rate for respiratory rate? ›Respiration rates may increase with fever, illness, and other medical conditions. When checking respiration, it is important to also note whether a person has any difficulty breathing. Normal respiration rates for an adult person at rest range from 12 to 16 breaths per minute.
Why might cardiologist find it useful to study zebrafish? ›Zebrafish embryos are transparent, making it easy to spot abnormalities. Particularly helpful for cardiology research: mutant embryos lacking active circulation are capable of surviving up to 5 days post fertilization. And zebrafish hearts are simpler than mammals': theirs have just two chambers, while ours have four.
How is a zebrafish heart similar to a human heart? ›The Zebrafish adult heart is not the same as the human heart as it has a simpler structure, but it is similar enough to replicate cardiovascular function. It only has a single atrium and ventricle (which contains two kinds of cardiac muscle), but these work in an equivalent way to those of a human heart.
Why might cardiologists heart doctors find it useful to study zebrafish? ›In humans, the heart cannot repair itself. But zebrafish can repair their hearts - heart muscle cells near the damaged area lose their muscle properties and revert back to stem cells, which can repair the heart tissue.
What is unique about the fish heart? ›Fish do not have a very powerful heart. It's a simple, four-chambered pump with two valves that circulates blood slowly throughout the body, which in turn slows the movement of oxygen and food in the body.
Which bird has the fastest heart rate? ›An active hummingbird's heart pumps at 1,200 beats per minute; a flying pigeon's heart beats at 600. But a human athlete during exercise builds up a heart rate to around only 150 beats, a mere fraction of the hummingbird's heart rate. Exercise as hard as you like.
Which animal has the fastest heartbeat rate? ›The heart of the Etruscan shrew, one of the world's smallest mammals, beats incredibly fast — up to 1,500 times per minute, or 25 times per second. The human heart, in comparison, is sluggish, beating only 60 to 100 times a minute. Then there's the heart of the blue whale, the largest animal ever to have lived.