Displaying publications 1 - 20 of 28 in total

Abstract:
Sort:
  1. Polystyrene nanoplastics synergistically exacerbate diclofenac toxicity in embryonic development and the health of adult zebrafish
    Kandaswamy K, Guru A, Panda SP, Antonyraj APM, Kari ZA, Giri J, et al.
    Comp Biochem Physiol C Toxicol Pharmacol, 2024 Jul;281:109926.
    PMID: 38641085 DOI: 10.1016/j.cbpc.2024.109926
    In this study, we investigated the possible ecotoxicological effect of co-exposure to polystyrene nanoplastics (PS-NPs) and diclofenac (DCF) in zebrafish (Danio rerio). After six days of exposure, we noticed that the co-exposure to PS-NP (100 μg/L) and DCF (at 50 and 500 μg/L) decreased the hatching rate and increased the mortality rate compared to the control group. Furthermore, we noted that larvae exposed to combined pollutants showed a higher frequency of morphological abnormalities and increased oxidative stress, apoptosis, and lipid peroxidation. In adults, superoxide dismutase and catalase activities were also impaired in the intestine, and the co-exposure groups showed more histopathological alterations. Furthermore, the TNF-α, COX-2, and IL-1β expressions were significantly upregulated in the adult zebrafish co-exposed to pollutants. Based on these findings, the co-exposure to PS-NPs and DCF has shown an adverse effect on the intestinal region, supporting the notion that PS-NPs synergistically exacerbate DCF toxicity in zebrafish.
    Matched MeSH terms: Embryo, Nonmammalian/drug effects
  2. Egg structure and outline of embryonic development of the basal mantodean, Metallyticus splendidus Westwood, 1835 (Insecta, Mantodea, Metallyticidae)
    Fukui M, Fujita M, Tomizuka S, Mashimo Y, Shimizu S, Lee CY, et al.
    Arthropod Struct Dev, 2018 Jan;47(1):64-73.
    PMID: 29109050 DOI: 10.1016/j.asd.2017.11.001
    The egg structure and outline of the embryonic development of Metallyticus splendidus of one of the basal Mantodea representatives, Metallyticidae, were described in the present study. The results obtained were compared with those from the previous studies, to reconstruct and discuss the groundplan of Mantodea and Dictyoptera. In M. splendidus, the egg is spheroidal, it has a convex ventral side at the center in which numerous micropyles are grouped, and it possesses a conspicuous hatching line in its anterior half. These are the groundplan features of mantodean eggs and the "grouped micropyles in the ventral side of the egg" are regarded as an apomorphic groundplan feature of Dictyoptera. A small circular embryo is formed by a simple concentration of blastoderm cells, which then undergoes embryogenesis of the typical short germ band type. Blastokinesis is of the "non-reversion type" and the embryo keeps its original superficial position and original orientation throughout embryonic development. During the middle stages of development, the embryo undergoes rotation around the egg's anteroposterior axis. These features are a part of the groundplan of Mantodea. It is uncertain whether sharing of the "non-reversion type" of blastokinesis by Mantodea and blaberoidean Blattodea can be regarded as homology or homoplasy.
    Matched MeSH terms: Embryo, Nonmammalian/embryology*
  3. Fulltext Toxicity of buprofezin on the survival of embryo and larvae of African catfish, Clarias gariepinus (Bloch)
    Marimuthu K, Muthu N, Xavier R, Arockiaraj J, Rahman MA, Subramaniam S
    PLoS One, 2013;8(10):e75545.
    PMID: 24098390 DOI: 10.1371/journal.pone.0075545
    Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus) as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L) of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatment for all the concentrations. The mortality of embryos was significantly increased with increasing buprofezin concentrations from 5 to 100 mg/L (p< 0.05). However, the mortality was not significantly different (p<0.05) among the following concentrations: 0 (control), 0.05, 0.5 and 5 mg/L. Data obtained from the buprofezin acute toxicity tests were evaluated using probit analysis. The 24 h LC50 value (with 95% confidence limits) of buprofezin for embryos was estimated to be 6.725 (3.167-15.017) mg/L. The hatching of fish embryos was recorded as 68.8, 68.9, 66.9, 66.4, 26.9, 25.1 and 0.12% in response to 7 different concentrations of buprofezin, respectively. The mortality rate of larvae significantly (p<0.05) increased with increasing buprofezin concentrations exposed to 24-48 h. The 24 and 48 h LC50 values (with 95% confidence limits) of buprofezin for the larvae was estimated to be 5.702 (3.198-8.898) and 4.642 (3.264-6.287) mg/L respectively. There were no significant differences (p>0.05) in the LC50 values obtained at 24 and 48 h exposure times. Malformations were observed when the embryos and larvae exposed to more than 5 mg/L. The results emerged from the study suggest that even the low concentration (5 mg/L) of buprofezin in the aquatic environment may have adverse effect on the early embryonic and larval development of African catfish.
    Matched MeSH terms: Embryo, Nonmammalian/abnormalities; Embryo, Nonmammalian/drug effects*
  4. Effect of mercury and cadmium on early life stages of Java medaka (Oryzias javanicus): a potential tropical test fish
    Ismail A, Yusof S
    Mar Pollut Bull, 2011;63(5-12):347-9.
    PMID: 21377175 DOI: 10.1016/j.marpolbul.2011.02.014
    Several organisms have been used as indicators, bio-monitoring agents or test organisms in ecotoxicological studies. A close relative of the well established Japanese medaka, the Java medaka (Oryzias javanicus), has the potential to be a test organism. The fish is native to the estuaries of the Malaysian Peninsula, Thailand, Indonesia and Singapore. In this study, newly fertilised eggs were exposed to different concentrations of Cd and Hg. Observations were done on the development of the embryos. Exposure to low levels of Cd and Hg (0.01-0.05 ppm) resulted in several developmental disorders that led to death. Exposure to ≥1.0 ppm Cd resulted in immediate developmental arrest. The embryos of Java medaka showed tolerance to a certain extent when exposed to ≥1.0 ppm Hg compared to Cd. Based on the sensitivity of the embryos, Java medaka is a suitable test organism for ecotoxicology in the tropical region.
    Matched MeSH terms: Embryo, Nonmammalian/abnormalities; Embryo, Nonmammalian/drug effects
  5. Fulltext Use of Zebrafish Embryo Assay to Evaluate Toxicity and Safety of Bioreactor-Grown Exopolysaccharides and Endopolysaccharides from European Ganoderma applanatum Mycelium for Future Aquaculture Applications
    Wan-Mohtar WAAQI, Ilham Z, Jamaludin AA, Rowan N
    Int J Mol Sci, 2021 Feb 07;22(4).
    PMID: 33562361 DOI: 10.3390/ijms22041675
    Natural mycelial exopolysaccharide (EPS) and endopolysaccharide (ENS) extracted from bioreactor-cultivated European Ganoderma applanatum mushrooms are of potential high commercial value for both food and adjacent biopharmaceutical industries. In order to evaluate their potential toxicity for aquaculture application, both EPS (0.01-10 mg/mL) and ENS (0.01-10 mg/mL) extracts were tested for Zebrafish Embryo Toxicity (ZFET); early development effects on Zebrafish Embryos (ZE) were also analyzed between 24 and 120 h post-fertilization (HPF). Both EPS and ENS are considered non-toxic with LC50 of 1.41 mg/mL and 0.87 mg/mL respectively. Both EPS and ENS did not delay hatching and teratogenic defect towards ZE with <1.0 mg/mL, respectively. No significant changes in the ZE heart rate were detected following treatment with the two compounds tested (EPS: 0.01-10 mg/mL: 176.44 ± 0.77 beats/min and ENS: 0.01-10 mg/mL: 148.44 ± 17.75 beats/min) compared to normal ZE (120-180 beats/min). These initial findings support future pre-clinical trials in adult fish models with view to safely using EPS and ENS as potential feed supplements for supplements for development of the aquaculture industry.
    Matched MeSH terms: Embryo, Nonmammalian/cytology*; Embryo, Nonmammalian/drug effects
  6. Assessment of anti-inflammatory effect of 5β-hydroxypalisadin B isolated from red seaweed Laurencia snackeyi in zebrafish embryo in vivo model
    Wijesinghe WA, Kim EA, Kang MC, Lee WW, Lee HS, Vairappan CS, et al.
    Environ Toxicol Pharmacol, 2014 Jan;37(1):110-7.
    PMID: 24317194 DOI: 10.1016/j.etap.2013.11.006
    5β-Hydroxypalisadin B, a halogenated secondary metabolite isolated from red seaweed Laurencia snackeyi was evaluated for its anti-inflammatory activity in lipopolysaccharide (LPS)-induced zebrafish embryo. Preliminary studies suggested the effective concentrations of the compound as 0.25, 0.5, 1 μg/mL for further in vivo experiments. 5β-Hydroxypalisadin B, exhibited profound protective effect in the zebrafish embryo as confirmed by survival rate, heart beat rate, and yolk sac edema size. The compound acts as an effective agent against reactive oxygen species (ROS) formation induced by LPS and tail cut. Moreover, 5β-hydroxypalisadin B effectively inhibited the LPS-induced nitric oxide (NO) production in zebrafish embryo. All the tested protective effects of 5β-hydroxypalisadin B were comparable to the well-known anti-inflammatory agent dexamethasone. According to the results obtained, 5β-hydroxypalisadin B isolated from red seaweed L. snackeyi could be considered as an effective anti-inflammatory agent which might be further developed as a functional ingredient.
    Matched MeSH terms: Embryo, Nonmammalian/drug effects; Embryo, Nonmammalian/metabolism
  7. Fulltext Embryos of the viviparous dermapteran, Arixenia esau develop sequentially in two compartments: terminal ovarian follicles and the uterus
    Tworzydlo W, Kisiel E, Bilinski SM
    PLoS One, 2013;8(5):e64087.
    PMID: 23667700 DOI: 10.1371/journal.pone.0064087
    Three main reproductive strategies have been described among insects: most common oviparity, ovoviviparity and viviparity. In the latter strategy, the embryonic development takes place within the body of the mother which provides gas exchange and nutrients for embryos. Here we present the results of histological and EM analyses of the female reproductive system of the viviparous earwig, Arixenia esau, focusing on all the modifications related to the viviparity. We show that in the studied species the embryonic development consists of two "physiological phases" that take place in two clearly disparate compartments, i.e. the terminal ovarian follicle and the uterus. In both compartments the embryos are associated with synthetically active epithelial cells. We suggest that these cells are involved in the nourishment of the embryo. Our results indicate that viviparity in arixeniids is more complex than previously considered. We propose the new term "pseudoplacento-uterotrophic viviparity" for this unique two-phase reproductive strategy.
    Matched MeSH terms: Embryo, Nonmammalian/embryology; Embryo, Nonmammalian/ultrastructure
  8. Transformation of crystalline starch nanoparticles into highly luminescent carbon nanodots: Toxicity studies and their applications
    Sonthanasamy RSA, Ahmad WYW, Fazry S, Hassan NI, Lazim AM
    Carbohydr Polym, 2016 Feb 10;137:488-496.
    PMID: 26686155 DOI: 10.1016/j.carbpol.2015.11.021
    Being abundant in many tropical part of the world, Dioscorea sp. as food is limited due to its toxicity. However polysaccharides derive from these tubers could be important for other applications. Here we developed a Highly Luminescent Carbon Nanodots (C-dots) via acid hydrolysis of Gadong starch (GS). The hydrolysis rate of GS increased from 49% to 86% within 7 days while the X-ray diffraction showed the native GS particle is a C-crystalline type. The GS particles were either round or oval with diameters ranging from 50-90 nm. Further acid dehydration and surface oxidation reduced the size of GS nanoparticles to 6-25 nm. The C-dots produced a fluorescent emission at wavelength 441 nm. Toxicity tests demonstrate that zebrafish embryo were able to tolerate the C-dots for 48 h after exposure. This study has successfully demonstrated a novel approach of converting GS into excellent fluorescent C-dot.
    Matched MeSH terms: Embryo, Nonmammalian/drug effects
  9. Postnatal growth rates covary weakly with embryonic development rates and do not explain adult mortality probability among songbirds on four continents
    Martin TE, Oteyza JC, Mitchell AE, Potticary AL, Lloyd P
    Am Nat, 2015 Mar;185(3):380-9.
    PMID: 25674692 DOI: 10.1086/679612
    Growth and development rates may result from genetic programming of intrinsic processes that yield correlated rates between life stages. These intrinsic rates are thought to affect adult mortality probability and longevity. However, if proximate extrinsic factors (e.g., temperature, food) influence development rates differently between stages and yield low covariance between stages, then development rates may not explain adult mortality probability. We examined these issues based on study of 90 songbird species on four continents to capture the diverse life-history strategies observed across geographic space. The length of the embryonic period explained little variation (ca. 13%) in nestling periods and growth rates among species. This low covariance suggests that the relative importance of intrinsic and extrinsic influences on growth and development rates differs between stages. Consequently, nestling period durations and nestling growth rates were not related to annual adult mortality probability among diverse songbird species within or among sites. The absence of a clear effect of faster growth on adult mortality when examined in an evolutionary framework across species may indicate that species that evolve faster growth also evolve physiological mechanisms for ameliorating costs on adult mortality. Instead, adult mortality rates of species in the wild may be determined more strongly by extrinsic environmental causes.
    Matched MeSH terms: Embryo, Nonmammalian/physiology
  10. Fulltext Synthesis, Characterization, and Toxicity Assessment of Pluronic F127-Functionalized Graphene Oxide on the Embryonic Development of Zebrafish (Danio rerio)
    Shamsi S, Alagan AA, Sarchio SNE, Md Yasin F
    Int J Nanomedicine, 2020;15:8311-8329.
    PMID: 33149578 DOI: 10.2147/IJN.S271159
    Background: In the current literature, there are ongoing debates on the toxicity of graphene oxide (GO) that demonstrate contradictory findings regarding its toxicity profile. As a potential drug carrier, these findings are very concerning due to the safety concerns in humans, as well as the dramatic rise of GO being excreted into the environment. Therefore, there is an imperative need to mitigate the potential toxicity of GO to allow for a safer application in the future.

    Purpose: The present study aims to address this issue by functionalizing GO with Pluronic F127 (PF) as a means to mitigate toxicity and resolve the biocompatibility of GO. Although results from previous studies generally indicated that Pluronic functionalized GO exhibits relatively low toxicity to living organisms, reports that emphasize on its toxicity, particularly during embryonic developmental stage, are still scarce.

    Methods: In the present study, two different sizes of native GO samples, GO and NanoGO, as well as PF-functionalized GO, GO-PF and NanoGO-PF, were prepared and characterized using DLS, UV-Vis, Raman spectroscopy, FTIR, and FESEM analyses. Toxicological assessment of all GO samples (0-100 µg/mL) on zebrafish embryonic developmental stages (survival, hatching and heart rates, and morphological changes) was recorded daily for up to 96 hours post-fertilization (hpf).

    Results: The toxicity effects of each GO sample were observed to be higher at increasing concentrations and upon prolonged exposure. NanoGO demonstrated lower toxicity effects compared to GO. GO-PF and NanoGO-PF were also found to have lower toxicity effects compared to native GO samples. GO-PF showed the lowest toxicity response on zebrafish embryo.

    Conclusion: These findings highlight that toxicity is dependent on the concentration, size, and exposure period of GO. Functionalization of GO with PF through surface coating could potentially mitigate the toxicity effects of GO in embryonic developmental stages, but further investigation is warranted for broader future applications.

    Matched MeSH terms: Embryo, Nonmammalian/drug effects
  11. Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate
    Martin TE, Ton R, Niklison A
    Ecol Lett, 2013 Jun;16(6):738-45.
    PMID: 23473270 DOI: 10.1111/ele.12103
    Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species.
    Matched MeSH terms: Embryo, Nonmammalian/metabolism
  12. Fertilization, hatching, and embryogenesis of diploid and triploid eggs of Anabas testudineus (Bloch, 1792)
    Hassan A, Okomoda VT, Sanusi FAB
    Zygote, 2018 Oct;26(5):343-349.
    PMID: 30296962 DOI: 10.1017/S0967199418000187
    SummaryThis study investigated the breeding parameters and embryogenic development of diploid and heat shock-induced triploid eggs of Anabas testudineus (Bloch, 1792). To this effect, broodstocks of A. testudineus were induced to spawn using the Ovaprim® hormone. After fertilization, the eggs were divided into two groups and one portion heat shocked at 41°C (for 3 min), at approximately 4 min after fertilization. Results of fertilization, hatchability, as well as the sequence and timing of embryogenic development were collated from three breeding trials. Fertilization percentages were similar in both treatments (≈90%) while hatchability was higher in the diploid eggs (79.56%) than the triploid induced eggs (50.04%). Both treatments had the same sequence of embryogenetic stages; however, the timing of development was significantly delayed in the triploids (i.e. beyond the 2-cell stages) as compared with the observations in the control group (diploid eggs). Consequently, hatching time was 5 h faster in the diploid eggs [i.e. 18 hours post fertilization (hpf)] compared with the triploid induced eggs (23 hpf). The most critical stage of embryonic development in which mass mortality occurred in the different treatments was the somite stage. The status of triploid hatchlings was affirmed using erythrocyte morphology in 2-month-old fingerlings.
    Matched MeSH terms: Embryo, Nonmammalian/cytology
  13. Development of a zebrafish model for toxicity evaluation of adulterated Apis mellifera honey
    Fakhlaei R, Selamat J, Abdull Razis AF, Sukor R, Ahmad S, Khatib A, et al.
    Chemosphere, 2024 May;356:141736.
    PMID: 38554873 DOI: 10.1016/j.chemosphere.2024.141736
    Since ancient times, honey has been used for medical purposes and the treatment of various disorders. As a high-quality food product, the honey industry is prone to fraud and adulteration. Moreover, limited experimental studies have investigated the impact of adulterated honey consumption using zebrafish as the animal model. The aims of this study were: (1) to calculate the lethal concentration (LC50) of acid-adulterated Apis mellifera honey on embryos, (2) to investigate the effect of pure and acid-adulterated A. mellifera honey on hatching rate (%) and heart rate of zebrafish (embryos and larvae), (3) to elucidate toxicology of selected adulterated honey based on lethal dose (LD50) using adult zebrafish and (4) to screen the metabolites profile of adulterated honey from blood serum of adult zebrafish. The result indicated the LC50 of 31.10 ± 1.63 (mg/ml) for pure A. mellifera honey, while acetic acid demonstrates the lowest LC50 (4.98 ± 0.06 mg/ml) among acid adulterants with the highest mortality rate at 96 hpf. The treatment of zebrafish embryos with adulterated A. mellifera honey significantly (p ≤ 0.05) increased the hatching rate (%) and decreased the heartbeat rate. Acute, prolong-acute, and sub-acute toxicology tests on adult zebrafish were conducted at a concentration of 7% w/w of acid adulterants. Furthermore, the blood serum metabolite profile of adulterated-honey-treated zebrafish was screened by LC-MS/MS analysis and three endogenous metabolites have been revealed: (1) Xanthotoxol or 8-Hydroxypsoralen, (2) 16-Oxoandrostenediol, and (3) 3,5-Dicaffeoyl-4-succinoylquinic acid. These results prove that employed honey adulterants cause mortality that contributes to higher toxicity. Moreover, this study introduces the zebrafish toxicity test as a new promising standard technique for the potential toxicity assessment of acid-adulterated honey in this study and hazardous food adulterants for future studies.
    Matched MeSH terms: Embryo, Nonmammalian/drug effects
  14. Zebrafish phenotypic screen identifies novel Notch antagonists
    Velaithan V, Okuda KS, Ng MF, Samat N, Leong SW, Faudzi SM, et al.
    Invest New Drugs, 2017 04;35(2):166-179.
    PMID: 28058624 DOI: 10.1007/s10637-016-0423-y
    Zebrafish represents a powerful in vivo model for phenotype-based drug discovery to identify clinically relevant small molecules. By utilizing this model, we evaluated natural product derived compounds that could potentially modulate Notch signaling that is important in both zebrafish embryogenesis and pathogenic in human cancers. A total of 234 compounds were screened using zebrafish embryos and 3 were identified to be conferring phenotypic alterations similar to embryos treated with known Notch inhibitors. Subsequent secondary screens using HEK293T cells overexpressing truncated Notch1 (HEK293TΔE) identified 2 compounds, EDD3 and 3H4MB, to be potential Notch antagonists. Both compounds reduced protein expression of NOTCH1, Notch intracellular domain (NICD) and hairy and enhancer of split-1 (HES1) in HEK293TΔE and downregulated Notch target genes. Importantly, EDD3 treatment of human oral cancer cell lines demonstrated reduction of Notch target proteins and genes. EDD3 also inhibited proliferation and induced G0/G1 cell cycle arrest of ORL-150 cells through inducing p27KIP1. Our data demonstrates the utility of the zebrafish phenotypic screen and identifying EDD3 as a promising Notch antagonist for further development as a novel therapeutic agent.
    Matched MeSH terms: Embryo, Nonmammalian/abnormalities; Embryo, Nonmammalian/drug effects
  15. CTP synthase knockdown during early development distorts the nascent vertebral column and causes fluid retention in multiple tissues in zebrafish
    Dzaki N, Wahab W, Azlan A, Azzam G
    Biochem Biophys Res Commun, 2018 10 20;505(1):106-112.
    PMID: 30241946 DOI: 10.1016/j.bbrc.2018.09.074
    CTP Synthase (CTPS) is a metabolic enzyme that is recognized as a catalyst for nucleotide, phospholipid and sialoglycoprotein production. Though the structural characteristics and regulatory mechanisms of CTPS are well-understood, little is known regarding the extent of its involvement during the early developmental stages of vertebrates. Zebrafish carries two CTPS genes, annotated as ctps1a and ctps1b. Phylogenetic analyses show that both genes had diverged from homologues in the ancestral Actinopterygii, Oreochromis niloticus. Conservation of common CTPS-catalytic regions further establishes that both proteins are likely to be functionally similar to hsaCTPS. Here, we show that ctps1a is more critical throughout the initial period of embryonic development than ctps1b. The effects of concurrent partial knockdown are dependent on ctps1a vs ctps1b dosage ratios. When these are equally attenuated, abnormal phenotypes acquired prior to the pharyngula period disappear in hatchlings (48hpf); however, if either gene is more attenuated than the other, these only become more pronounced in advanced stages. Generally, disruption to normal ctps1a or ctps1b expression levels by morpholinos culminates in the distortion of the early spinal column as well as multiple-tissue oedema. Other effects include slower growth rates, increased mortality rates and impaired structural formation of the young fish's extremities. Embryos grown in DON, a glutamine-analogue drug and CTPS antagonist, also exhibit similar characteristics, thus strengthening the validity of the morpholino-induced phenotypes observed. Together, our results demonstrate the importance of CTPS for the development of zebrafish embryos, as well as a disparity in activity and overall importance amongst isozymes.
    Matched MeSH terms: Embryo, Nonmammalian/embryology; Embryo, Nonmammalian/metabolism
  16. Fulltext RAC1 Missense Mutations in Developmental Disorders with Diverse Phenotypes
    Reijnders MRF, Ansor NM, Kousi M, Yue WW, Tan PL, Clarkson K, et al.
    Am J Hum Genet, 2017 Sep 07;101(3):466-477.
    PMID: 28886345 DOI: 10.1016/j.ajhg.2017.08.007
    RAC1 is a widely studied Rho GTPase, a class of molecules that modulate numerous cellular functions essential for normal development. RAC1 is highly conserved across species and is under strict mutational constraint. We report seven individuals with distinct de novo missense RAC1 mutations and varying degrees of developmental delay, brain malformations, and additional phenotypes. Four individuals, each harboring one of c.53G>A (p.Cys18Tyr), c.116A>G (p.Asn39Ser), c.218C>T (p.Pro73Leu), and c.470G>A (p.Cys157Tyr) variants, were microcephalic, with head circumferences between -2.5 to -5 SD. In contrast, two individuals with c.151G>A (p.Val51Met) and c.151G>C (p.Val51Leu) alleles were macrocephalic with head circumferences of +4.16 and +4.5 SD. One individual harboring a c.190T>G (p.Tyr64Asp) allele had head circumference in the normal range. Collectively, we observed an extraordinary spread of ∼10 SD of head circumferences orchestrated by distinct mutations in the same gene. In silico modeling, mouse fibroblasts spreading assays, and in vivo overexpression assays using zebrafish as a surrogate model demonstrated that the p.Cys18Tyr and p.Asn39Ser RAC1 variants function as dominant-negative alleles and result in microcephaly, reduced neuronal proliferation, and cerebellar abnormalities in vivo. Conversely, the p.Tyr64Asp substitution is constitutively active. The remaining mutations are probably weakly dominant negative or their effects are context dependent. These findings highlight the importance of RAC1 in neuronal development. Along with TRIO and HACE1, a sub-category of rare developmental disorders is emerging with RAC1 as the central player. We show that ultra-rare disorders caused by private, non-recurrent missense mutations that result in varying phenotypes are challenging to dissect, but can be delineated through focused international collaboration.
    Matched MeSH terms: Embryo, Nonmammalian/metabolism; Embryo, Nonmammalian/pathology
  17. Suitability of heat- and freeze-killed oothecae of the American cockroach (Dictyoptera: Blattidae) as hosts for an oothecal parasitoid, Aprostocetus hagenowii (Hymenoptera: Eulophidae)
    Tee HS, Saad AR, Lee CY
    J Econ Entomol, 2010 Oct;103(5):1770-4.
    PMID: 21061978
    The objective of this study was to evaluate the suitability of heat- and freeze-killed oothecae of Periplaneta americana (L.) (Dictyoptera: Blattidae) as hosts for parasitoid Aprostocetus hagenowii (Ratzeburg) (Hymenoptera: Eulophidae). The oothecae were subjected to -20, 45, 48, 50, and 55 degrees C at different exposure times (15, 30, 45, and 60 min). The effects of heat- and freeze-killed oothecae on several biological parameters (e.g., parasitism and emergence rates, developmental times, progeny number, and sex ratio) ofA. hagenowii were determined. Embryonic development of 2-d-old oothecae was terminated by either freezing at -20 degrees C or heating at > or = 48 degrees C for > or =30 min. A. hagenowii parasitized live oothecae as well as both heat- and freeze-killed oothecae. Percentage parasitism, emergence rates, and developmental times ofA. hagenowii in both heat- and freeze-killed oothecae were not significantly different from those of the live oothecae. Both heating and freezing did not influence progeny number (male and female) and sex ratio of A. hagenowii emerged from killed oothecae.
    Matched MeSH terms: Embryo, Nonmammalian
  18. Intracellular ROS scavenging and antioxidant regulation of WL15 from cysteine and glycine-rich protein 2 demonstrated in zebrafish in vivo model
    Guru A, Lite C, Freddy AJ, Issac PK, Pasupuleti M, Saraswathi NT, et al.
    Dev Comp Immunol, 2021 Jan;114:103863.
    PMID: 32918928 DOI: 10.1016/j.dci.2020.103863
    Antioxidant peptides are naturally present in food, especially in fishes, and are considered to contain rich source of various bioactive compounds that are structurally heterogeneous. This study aims to identify and characterize the antioxidant property of the WL15 peptide, derived from Cysteine and glycine-rich protein 2 (CSRP2) identified from the transcriptome of a freshwater food fish, Channa striatus. C. striatus is already studied to contain high levels of amino acids and fatty acids, besides traditionally known for its pharmacological benefits in the Southeast Asian region. In our study, in vitro analysis of WL15 peptide exhibited strong free radical scavenging activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide anion radical and hydrogen peroxide (H2O2) scavenging assay. Further, to evaluate the cytotoxicity and dose-response, the Human dermal fibroblast (HDF) cells were used. Results showed that the treatment of HDF cells with varying concentrations (10, 20, 30, 40 and 50 μM) of WL15 peptide was not cytotoxic. However, the treatment concentrations showed enhanced antioxidant properties by significantly inhibiting the levels of free radicals. For in vivo assessment, we have used zebrafish larvae for evaluating the developmental toxicity and for determining the antioxidant property of the WL15 peptide. Zebrafish embryos were treated with the WL15 peptide from 4 h of post-fertilization (hpf) to 96 hpf covering the embryo-larval developmental period. At the end of the exposure period, the larvae were exposed to H2O2 (1 mM) for inducing generic oxidative stress. The exposure of WL15 peptide during the embryo-larval period showed no developmental toxicity even in higher concentrations of the peptide. Besides, the WL15 peptide considerably decreased the intracellular reactive oxygen species (ROS) levels induced by H2O2 exposure. WL15 peptide also inhibited the H2O2-induced caspase 3-dependent apoptotic response in zebrafish larvae was observed using the whole-mount immunofluorescence staining. Overall results from our study showed that the pre-treatment of WL15 (50 μM) in the H2O2-exposed zebrafish larvae, attenuated the expression of activated caspase 3 expressions, reduced Malondialdehyde (MDA) levels, and enhanced antioxidant enzymes, including superoxide dismutase (SOD) and catalase (CAT). The gene expression of antioxidant enzymes such as glutathione S-transferase (GST), glutathione peroxide (GPx) and γ-glutamyl cysteine synthetase (GCS) was found to be upregulated. In conclusion, it can be conceived that pre-treatment with WL15 could mitigate H2O2-induced oxidative injury by elevating the activity and expression of antioxidant enzymes, thereby decreasing MDA levels and cellular apoptosis by enhancing the antioxidant response, demonstrated by the in vitro and in vivo experiments.
    Matched MeSH terms: Embryo, Nonmammalian
  19. Accumulation of trace metals in the embryos and hatchlings of Chelonia mydas from Peninsular Malaysia incubated at different temperatures
    Ikonomopoulou MP, Olszowy H, Francis R, Ibrahim K, Whittier J
    Sci Total Environ, 2013 Apr 15;450-451:301-6.
    PMID: 23500829 DOI: 10.1016/j.scitotenv.2013.02.031
    A variety of trace metals were measured in the egg contents of three clutches of Chelonia mydas collected from Kuala Terengganu state in Peninsular Malaysia. We quantified Mn, Cu, Zn, Se (essential trace metals) and As (anthropogenic pollutant) at several developmental stages obtained by incubating eggs at two different temperatures (27 °C and 31 °C). The incubation temperatures were chosen because they produce predominantly male or predominantly female hatchlings, respectively. The eggs were removed from the sand and washed before being placed in incubators, to ensure that the only possible source of the detected metals was maternal transfer. Other metals: Mo, Co, Ni, Cd, Sn, Sb, Hg, Tl and Pb (all non-essential metals) were detected at concentrations below the lower limit of quantitation (LLOQ). Trace metal concentrations, particularly [Zn], increased during development, other metals (Cu, As, Se and Cr) accumulated to a lesser degree than zinc but no significant differences were observed between the incubation temperatures at any stage of incubation. To date, only a few studies on trace metals in turtle embryos and hatchlings have been reported; this study will provide basic knowledge on the accumulation of trace metals during development at two different incubation temperatures.
    Matched MeSH terms: Embryo, Nonmammalian/metabolism*
  20. Fulltext Regulation of embryonic hematopoiesis by a cytokine-inducible SH2 domain homolog in zebrafish
    Lewis RS, Noor SM, Fraser FW, Sertori R, Liongue C, Ward AC
    J Immunol, 2014 Jun 15;192(12):5739-48.
    PMID: 24835394 DOI: 10.4049/jimmunol.1301376
    Cytokine-inducible SH2 domain-containing protein (CISH), a member of the suppressor of cytokine signaling family of negative feedback regulators, is induced by cytokines that activate STAT5 and can inhibit STAT5 signaling in vitro. However, demonstration of a definitive in vivo role for CISH during development has remained elusive. This study employed expression analysis and morpholino-mediated knockdown in zebrafish in concert with bioinformatics and biochemical approaches to investigate CISH function. Two zebrafish CISH paralogs were identified, cish.a and cish.b, with high overall conservation (43-46% identity) with their mammalian counterparts. The cish.a gene was maternally derived, with transcripts present throughout embryogenesis, and increasing at 4-5 d after fertilization, whereas cish.b expression commenced at 8 h after fertilization. Expression of cish.a was regulated by the JAK2/STAT5 pathway via conserved tetrameric STAT5 binding sites (TTCN3GAA) in its promoter. Injection of morpholinos targeting cish.a, but not cish.b or control morpholinos, resulted in enhanced embryonic erythropoiesis, myelopoiesis, and lymphopoiesis, including a 2- 3-fold increase in erythrocytic markers. This occurred concomitantly with increased activation of STAT5. This study indicates that CISH functions as a conserved in vivo target and regulator of STAT5 in the control of embryonic hematopoiesis.
    Matched MeSH terms: Embryo, Nonmammalian/immunology*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links