Limited contribution of photoenzymatic DNA repair in mitigating carry-over effects from larval UVB exposure: Implications for frog recruitment.

Solar ultraviolet-B (UVB) radiation has increased due to stratospheric ozone depletion, climate and ecosystem changes and is a driver of amphibian population declines. Photoenzymatic repair (PER) is a critical mechanism for limiting UVB lethality in amphibian larvae. However, the link between PER and the UVB-induced effects remains understudied through long-term investigations in vivo. Here, we assessed how larval PER determines the lethal and sublethal effects induced by environmentally relevant acute UVB exposure until the juvenile phase in the Neotropical frog Odontophrynus americanus. We conducted laboratory-based controlled experiments in which tadpoles were or were not exposed to UVB and subsequently were exposed to light (for PER activation) or dark treatments. Results showed that the rates of mortality and apoptosis observed in post-UVB dark treatment are effectively limited in post-UVB light treatment, indicating PER (and not dark repair, i.e. nucleotide excision repair) is critical to limit the immediate genotoxic impact of UVB-induced pyrimidine dimers. Nonetheless, even tadpoles that survived UVB exposure using PER showed sublethal complications that extended to the juvenile phase. Tadpole responses included alterations in morphology, chromosomal instability, increased skin susceptibility to fungal proliferation, as well as increased generation of reactive oxygen species. The short-term effects were carried over to later stages of life because metamorphosis time increased and juveniles were smaller. No body abnormalities were visualized in tadpoles, metamorphs, and juveniles, suggesting that O. americanus is UVB-resistant concerning these responses. This study reveals that even frog species equipped with an effective PER are not immune to carry-over effects from early UVB exposure, which are of great ecological relevance as late metamorphosis and smaller juveniles may impact individual performance and adult recruitment to breeding. Future ecological risk assessments and conservation and management efforts for amphibian species should exercise caution when linking PER effectiveness to UVB resistance.

Melanin pigmentation variations in the larval cuticle of almond moth, Ephestia cautella caused by gamma radiation.

To determine the effects of gamma radiation on the melanization process and phenoloxidase activity, Ephestia cautella larvae were exposed to dosages of 200, 400, 600, 800, and 1000 Gy. After irradiation, the number of non melanized larvae and the number exhibiting a slight melanization usually increased. The degree of melanization in treated larvae differed significantly from untreated larvae. The amount of melanin usually decreases as the dosage increases and as time passes after the treatment. The results of the phenoloxidase assay indicate that the enzyme activity responds differently to radiation. For instance, at doses of 200, 400, and 800 Gy, the enzyme activity remained consistent in both control and irradiated larvae. However, at doses of 600 and 1000 Gy, the enzyme activity increased to 14.92 and 13.37 O.D. units, respectively, compared to 8.81 O.D. units in the control. In order to determine if irradiated larvae have been previously exposed to ionizing radiation, a quick and easy test based on phenoloxidase activity or the melanization response is presented for use in quarantine treatment. Histological changes, specifically in the pigment granules of melanin, were studied using a light microscope. Upon inspection of the unirradiated larvae, it was observed that brown melanin pigment granules were deposited in the epicuticle and exocuticle layers of the cuticle. When gamma radiation dosages were administered to larvae, it was observed that the melanin pigment gradually diminished until it vanished at the highest dose (1000 Gy).

Zebrafish Larvae as a Model to Evaluate Potential Radiosensitizers or Protectors.

Zebrafish are extensively used in several kinds of research because they are one of the easily maintained vertebrate models and exhibit several features of a unique and convenient model system. As highly proliferative cells are more susceptible to radiation-induced DNA damage, zebrafish embryos are a front-line in vivo model in radiation research. In addition, this model projects the effect of radiation and different drugs within a short time, along with major biological events and associated responses. Several cancer studies have used zebrafish, and this protocol is based on the use of radiation modifiers in the context of radiotherapy and cancer. This method can be readily used to validate the effects of different drugs on irradiated and control (non-irradiated) embryos, thus identifying drugs as radio sensitizing or protective drugs. Although this methodology is used in most drug screening experiments, the details of the experiment and the toxicity assessment with the background of X-ray radiation exposure are limited or only briefly addressed, making it difficult to perform. This protocol addresses this issue and discusses the procedure and toxicity evaluation with a detailed illustration. The procedure describes a simple approach for using zebrafish embryos for radiation studies and radiation-based drug screening with much reliability and reproducibility.

Increasing radiation doses in Anastrepha obliqua (Diptera: Tephritidae) larvae improve parasitoid mass-rearing attributes.

Doses of 40, 80, 120, and 160 Gy were applied to 5-, 6-, 7-, and 8-day-old Anastrepha obliqua larvae, which were exposed to the Neotropical-native braconids Doryctobracon crawfordi and Utetes anastrephae and the Asian braconid Diachasmimorpha longicaudata. These tests were performed to know the effect of the increase in host radiation on the emergence of the aforementioned parasitoids and the related consequences of oviposition on the host. The study was based on the fact that higher radiation doses may cause a decrease in the host immune activity. There was a direct relationship between the increase in radiation dose and the parasitoid emergence. Both, the weight and the mortality of the host larvae were not affected by radiation. Although the larval weight of the larvae was lower and the mortality was higher in the younger larvae. Both, the number of scars and immature stages per host puparium originated from the younger larvae were lower than those from older larvae. Only U. anastrephae superparasitized more at lower radiation. Superparasitism by D. longicaudata was more frequent at 160 Gy. Qualitative measurements of melanin in the larvae parasitized showed that the levels were lower with increasing radiation. As radiation doses increased, the antagonistic response of the A. obliqua larva was reduced. Host larvae aged 5- and 6-day-old irradiated at 120-160 Gy significantly improve parasitoid emergence. This evidence is relevant for the mass production of the three tested parasitoid species.

Effects of X-ray irradiation on the fitness of the established invasive pest fall armyworm Spodoptera frugiperda.

BACKGROUND: Spodoptera frugiperda has spread to Africa, Asia, and Oceania, posing a serious threat to global agriculture. We estimated the appropriate dose of X-ray sterilization for S. frugiperda using an X-ray irradiation instrument to investigate environmentally acceptable control techniques, laying the framework for future applications of sterile insect technology (SIT) to manage the pest environmentally-friendly. RESULTS: This study is the first to investigate the effects of X-ray irradiation on the growth, development, survival, reproduction, and flight of S. frugiperda. The results showed that irradiation with 50-400 Gy had no significant effect on pupal eclosion, but females were more sensitive than males in terms of reproductive parameters, especially when doses of radiation were > 350 Gy. After irradiation with a sub-sterilizing dose of 250 Gy, the parental sterility rate was > 85%, and the sterility traits could be passed on to their offspring, resulting in a continuous decrease in the population of F1 and F2 generations. CONCLUSION: Our laboratory experiments theoretically confirmed the feasibility of SIT for controlling S. frugiperda in the field using X-ray radiation. This study provides a theoretical basis for future regional pest management strategies. © 2022 Society of Chemical Industry.

Differential gene expression analysis identified determinants of cell fate plasticity during radiation-induced regeneration in Drosophila.

Ionizing radiation (IR) is used to treat half of all cancer patients because of its ability to kill cells. IR, however, can induce stem cell-like properties in non-stem cancer cells, potentiating tumor regrowth and reduced therapeutic success. We identified previously a subpopulation of cells in Drosophila larval wing discs that exhibit IR-induced stem cell-like properties. These cells reside in the future wing hinge, are resistant to IR-induced apoptosis, and are capable of translocating, changing fate, and participating in regenerating the pouch that suffers more IR-induced apoptosis. We used here a combination of lineage tracing, FACS-sorting of cells that change fate, genome-wide RNAseq, and functional testing of 42 genes, to identify two key changes that are required cell-autonomously for IR-induced hinge-to-pouch fate change: (1) repression of hinge determinants Wg (Drosophila Wnt1) and conserved zinc-finger transcription factor Zfh2 and (2) upregulation of three ribosome biogenesis factors. Additional data indicate a role for Myc, a transcriptional activator of ribosome biogenesis genes, in the process. These results provide a molecular understanding of IR-induced cell fate plasticity that may be leveraged to improve radiation therapy.

Copper uptake in adult rainbow trout irradiated during early life stages and in non-irradiated bystander trout which swam with the irradiated fish.

PURPOSE: This investigation forms part of a wider study into the legacy effects of exposure of rainbow trout eggs 38 h after fertilization, eyed eggs, yolk sac larvae (YSL) or first feeders to a single 0.5 Gy X-ray dose, including the induction of a bystander effect, by the irradiated fish, to non-irradiated fish. Fish may be exposed to multiple environmental stressors, including waterborne metals, during their lifespan and, while there are data on how the legacy of early life stage irradiation and bystander effect induction is affected by waterborne aluminum and cadmium, there are no studies into the effects radiation or the radiation induced bystander effect on metal uptake. Therefore the aim of this investigation was to determine if the legacy of early life stage irradiation included an effect on copper uptake by adult fish and by non-irradiated bystander adult trout which swam with the irradiated fish. METHODS: The four early life stages mentioned above were exposed to a single 0.5 Gy X-ray dose and then maintained, for two years with no further irradiation. At two years old the irradiated fish were allowed to swim, for 2 h with non-irradiated bystander trout (also two years old). After this time copper uptake was determined using 64Cu. RESULTS: Copper uptake was increased in adult trout irradiated as eggs at 48 h after fertilization and as first feeders but eyed egg or YSL irradiation had no effect. Copper uptake was also increased in the bystander trout which swam with trout irradiated as eggs at 48 h after fertilization and as eyed eggs but there was no effect on non-irradiated adult trout which swam with trout irradiated as YSL or first feeders. CONCLUSIONS: When put in context with the proteomic changes observed in these fish we propose the increased copper uptake in adult trout irradiated as eggs at 48 h after fertilization could be part of an anti-tumorigenic response and the increase in copper uptake in adult trout irradiated as first feeders could be part of a potentially protective pro-apoptotic response. Similarly we propose the increase in copper uptake in non-irradiated adult trout, induced by trout irradiated as eggs at 48 h after fertilization or as eyed eggs, was part of the universally anti-tumorigenic nature of the X-ray induced bystander effect in fish. However this was exclusive to embryonic irradiation.

3.5-GHz radiofrequency electromagnetic radiation promotes the development of Drosophila melanogaster.

With the rapidly increasing popularity of 5G mobile technology, the effect of radiofrequency radiation on human health has caused public concern. This study explores the effects of a simulated 3.5 GHz radiofrequency electromagnetic radiation (RF-EMF) environment on the development and microbiome of flies under intensities of 0.1 W/m2, 1 W/m2 and 10 W/m2. We found that the pupation percentages in the first 3 days and eclosion rate in the first 2 days were increased under exposure to RF-EMF, and the mean development time was shortened. In a study on third-instar larvae, the expression levels of the heat shock protein genes hsp22, hsp26 and hsp70 and humoral immune system genes AttC, TotC and TotA were all significantly increased. In the oxidative stress system, DuoX gene expression was decreased, sod2 and cat gene expression levels were increased, and SOD and CAT enzyme activity also showed a significant increase. According to the 16S rDNA results, the diversity and species abundance of the microbial community decreased significantly, and according to the functional prediction analysis, the genera Acetobacter and Lactobacillus were significantly increased. In conclusion, 3.5 GHz RF-EMF may enhance thermal stress, oxidative stress and humoral immunity, cause changes in the microbial community, and regulate the insulin/TOR and ecdysteroid signalling pathways to promote fly development.

60Co-γ Radiation Alters Developmental Stages of Zeugodacus cucurbitae (Diptera: Tephritidae) Through Apoptosis Pathways Gene Expression.

Radiation is considered as a promising insect pest control strategy for minimizing postharvest yield losses. Among various techniques, irradiation is a method of choice as it induces lethal biochemical or molecular changes that cause a downstream cascade of abrupt physiological abnormalities at the cellular level. In this study, we evaluated the effect of 60Co-γ radiation on various developmental stages of Zeugodacus cucurbitae Coquillett and subsequent carry-over effects on the progeny. For this purpose, we treated eggs with 30- and 50-Gy radiation doses of 60Co-γ. We found that radiation significantly affected cellular antioxidants, insect morphology, and gene expression profiles. Our results indicate that in response to various doses of irradiation reactive oxygen species, catalase, peroxidase, and superoxide dismutase activities were increased along with a significant increase in the malondialdehyde (MDA) content. We observed higher mortality rates during the pupal stage of the insects that hatched from irradiated eggs (50 Gy). Furthermore, the life span of the adults was reduced in response to 50 Gy radiation. The negative effects carried over to the next generation were marked by significantly lower fecundity in the F1 generation of the irradiation groups as compared to control. The radiation induced morphological abnormalities at the pupal, as well as the adult, stages. Furthermore, variations in the gene expression following irradiation are discussed. Taken together, our results signify the utility of 60Co-γ radiation for fruit fly postharvest management.

Morphometric analysis - effect of the radiofrequency interface of electromagnetic field on the size of hatched Dermacentor reticulatus larvae.

INTRODUCTION AND OBJECTIVE: Electromagnetic radiation interactions with living systems have been one of determining factors in biological evolution. This study investigates the effect of 900 MHz radiofrequency (RF) electromagnetics field (EMF) exposure of eggs on the development of Dermacentor reticulatus larvae. The basic objective was to determine whether the 900 MHz RF-EMF has the potential to influence the size of the body of the hatched larvae of D. reticulatus ticks. MATERIAL AND METHODS: To this aim, eggs from 3 fully engorged females of D. reticulatus were included in the test procedure. Altogether four groups of eggs were designated which included eggs from each female. We used RF-EMF frequency of 900 MHz. Eggs were exposed to EMF for different time periods (30, 60 and 90 minutes) in dark, electromagnetically shielded anechoic chamber. After the irradiation eggs were allowed to hatch in climatic chamber. Randomly selected 200 larval individuals were measured to get basic morphological records. Four body traits including the total body length (TBL), length of gnathosoma with scutum (GSL), the total body width (TBW), and the width of basis capituli (BCW) were measured. RESULTS: The D. reticulatus larvae hatched from eggs exposed for 60 minutes, had demonstrably larger dimensions of all measured body traits not only as a control unexposed group but also as other experimental groups. CONCLUSIONS: The study shows, particularly, that artificial EMF that is used in smartphone technology impacts seriously D. reticulatus larvae development.

Ultraviolet-B irradiance and cumulative dose combine to determine performance and survival.

Despite decades of research, the role of elevated solar ultraviolet-B radiation (UVBR; 280-315 nm) in shaping amphibian populations remains ambiguous. These difficulties stem partly from a poor understanding of which parameters of UVBR exposure - dose, irradiance, and time interval - determine UVBR exposure health risk, and the potentially erroneous assumption that effects are proportional to the dose of exposure, irrespective of the administered regime (Bunsen-Roscoe Law of Reciprocity; BRL). We tested if the BRL holds with respect to UVBR-induced physiological effects in amphibians by acutely exposing tadpoles of the Australian green tree frog (Litoria caerulea) to a combination of different UVBR irradiances and doses in a fully factorial experiment. The BRL was invalid across all metrics assessed, with UVBR irradiance influencing the effects of a given dose on growth, coloration and burst swimming performance of larvae. We demonstrated some of the first empirical evidence for beneficial physiological effects of UVBR exposure in a larval amphibian, with improvements in growth, burst swimming performance and survival at the highest UVBR doses, contrary to hypotheses. Our findings demonstrate the species-specific nature of amphibian responses to UVBR, and the importance of UVBR irradiance in influencing the long-term physiological effects of a given dose of radiation. This work enhances our understanding of which parameters of complex UVBR exposures determine amphibian health risk.

Sinusoidal analysis reveals a non-linear and dopamine-dependent relationship between ambient illumination and motor activity in larval zebrafish.

Larval zebrafish show stereotyped motor responses to changes in ambient illumination. The responses can be evaluated in 96-well plates, and are used widely to assess neurological function in zebrafish models. However, the square-wave (on/off) light stimuli commonly employed in these studies do not allow analysis of the relationship between motor activity and illumination intensity or its rate of change. To address this limitation, we measured larval zebrafish motor function while ambient illumination was modulated sinusoidally. Motor activity varied robustly and reproducibly in antiphase with illumination. The relationship between mean swimming speed (dependent variable) and illuminance (independent variable) was described most closely by a power function, and was influenced dynamically by the proportional rate of change of illuminance. Several predictions from this model were verified experimentally by testing responses to sinusoidal illumination waveforms that were amplitude-, phase-, or offset-modulated, or transformed by a power function. At concentrations ≤5 µM, the dopamine D2 receptor inverse agonist haloperidol selectively abrogated the motor response to decreasing Illuminance without altering baseline activity in bright light, suggesting that dopamine is essential for illuminance-dependent motor function. These data contribute to understanding the environmental determinants of motor activity in zebrafish larvae, suggest experimental opportunities to elucidate underlying neural mechanisms, and potentially provide an assay of dopaminergic function for chemical and genetic screening applications.

The Impact of Graphite Oxide Nanocomposites on the Antibacterial Activity of Serum.

Nanoparticles can interact with the complement system and modulate the inflammatory response. The effect of these interactions on the complement activity strongly depends on physicochemical properties of nanoparticles. The interactions of silver nanoparticles with serum proteins (particularly with the complement system components) have the potential to significantly affect the antibacterial activity of serum, with serious implications for human health. The aim of the study was to assess the influence of graphite oxide (GO) nanocomposites (GO, GO-PcZr(Lys)2-Ag, GO-Ag, GO-PcZr(Lys)2) on the antibacterial activity of normal human serum (NHS), serum activity against bacteria isolated from alveoli treated with nanocomposites, and nanocomposite sensitivity of bacteria exposed to serum in vitro (using normal human serum). Additionally, the in vivo cytotoxic effect of the GO compounds was determined with application of a Galleria mellonella larvae model. GO-PcZr(Lys)2, without IR irradiation enhance the antimicrobial efficacy of the human serum. IR irradiation enhances bactericidal activity of serum in the case of the GO-PcZr(Lys)2-Ag sample. Bacteria exposed to nanocomposites become more sensitive to the action of serum. Bacteria exposed to serum become more sensitive to the GO-Ag sample. None of the tested GO nanocomposites displayed a cytotoxicity towards larvae.

Spherical arena reveals optokinetic response tuning to stimulus location, size, and frequency across entire visual field of larval zebrafish.

Many animals have large visual fields, and sensory circuits may sample those regions of visual space most relevant to behaviours such as gaze stabilisation and hunting. Despite this, relatively small displays are often used in vision neuroscience. To sample stimulus locations across most of the visual field, we built a spherical stimulus arena with 14,848 independently controllable LEDs. We measured the optokinetic response gain of immobilised zebrafish larvae to stimuli of different steradian size and visual field locations. We find that the two eyes are less yoked than previously thought and that spatial frequency tuning is similar across visual field positions. However, zebrafish react most strongly to lateral, nearly equatorial stimuli, consistent with previously reported spatial densities of red, green, and blue photoreceptors. Upside-down experiments suggest further extra-retinal processing. Our results demonstrate that motion vision circuits in zebrafish are anisotropic, and preferentially monitor areas with putative behavioural relevance.

Investigating the Joint Effects of Pesticides and Ultraviolet B Radiation in Xenopus laevis and Other Amphibians.

Exposure to multiple stressors often results in higher toxicity than one stressor alone. Examining joint effects of multiple stressors could provide more realistic exposure scenarios and a better understanding of the combined effects. In amphibian toxicology, simultaneous exposure to some pesticides and ultraviolet B (UVB) radiation has been suggested to be detrimental and more harmful in amphibian early-life stages than either stressor alone. Therefore, it is important to investigate the joint effects of these two stressors and provide data that could lead to more informed risk assessment. Here we describe how to set up a co-exposure to pesticides and ultraviolet B radiation to examine their joint toxicity in amphibian embryos and larvae, focusing on Xenopus laevis with notes on other amphibian species. With modifications, the methods may be applied to other types of chemicals or other aquatic organisms of interest.

Assessment of combining biosynthesized silver nanoparticles using Bacillus thuringiensis and gamma irradiation for controlling Pectinophora gossypiella (saunders) (lepidoptera: Gelechiidae).

PURPOSE: Combining gamma irradiation and nanotechnology has become one of the most promising new approaches for area-wide (AW) pest management in recent years. The laboratory trials were conducted to determine the combining effects of BT-AgNPs and gamma irradiation for controlling P. gossypiella. Radio-sensitivity of male pupae at different doses of gamma radiation and the effectiveness of biosynthesized silver nanoparticles using Bacillus thuringiensis on larval instar were assayed. Additionally, the ultrastructure changes on the alimentary canal of 4th instar larvae were studied to evaluate the impact of the combined approach at a cellular level. MATERIALS AND METHODS: Laboratory- rearing technique was used for rearing Pectinophora gossypiella. The irradiation process was achieved at Co60 - Gamma Chamber (4000 A). Alanine dosimeters were used for measuring the average absorbed dose and dose mapping. Preparation of Silver nanoparticles (AgNPs) using Bacillus thuringiensis (Bt) and their characterization has been investigated. The treated 4th instar larvae by gamma irradiation or ∕and BT-AgNPs were dissected under the stereo microscope. The alimentary canal was obtained anatomically and Transmission Electron Microscope) was used in examining the stained sections. RESULTS: Based on the nonhatching eggs produced by irradiated males' pupae, the values of effective doses were calculated. The effective doses ranged from 16 to 291 Gy for the ED25 - ED75. The sterility index reached 74.1% when irradiated with males by 291 Gy crossed with nonirradiated females and the adult emergence decreased to be 35.3%. The insecticidal potential of Bt-AgNPs on the 2nd and 4th larval instars was dose-dependent and its LC50 toxicity value was 0. 3 and 0. 4 mg/ml, respectively. The lethal concentration LC50 of the 2nd instar larvae increased the larval and pupal mortality to 55% and 44.4%, respectively, and reduced the adult emergence to be 55.6%. The combining effects of Bt-AgNPs with 291 Gy induced 100% pupae mortality and there was no adult emergence in F1 generation. Such effects also severed the ultrastructure deformity of the midgut of the 4th instar larvae after the two-day post-treatment. CONCLUSIONS: The combining effects are recommended as an effective IPM program to control P. gossypiella by releasing sterile males (derived from pupae irradiated with 291 Gy) crossing with the normal females in the field, and reducing the fertility of the population to 31.2%. Subsequently, the resulted larvae treated with LC50 of Bt-AgNPs prevented the adult emergence and stopped the life cycle of P. gossypiella.

Gravitational Experimental Platform for Animal Models, a New Platform at ESA's Terrestrial Facilities to Study the Effects of Micro- and Hypergravity on Aquatic and Rodent Animal Models.

Using rotors to expose animals to different levels of hypergravity is an efficient means of understanding how altered gravity affects physiological functions, interactions between physiological systems and animal development. Furthermore, rotors can be used to prepare space experiments, e.g., conducting hypergravity experiments to demonstrate the feasibility of a study before its implementation and to complement inflight experiments by comparing the effects of micro- and hypergravity. In this paper, we present a new platform called the Gravitational Experimental Platform for Animal Models (GEPAM), which has been part of European Space Agency (ESA)'s portfolio of ground-based facilities since 2020, to study the effects of altered gravity on aquatic animal models (amphibian embryos/tadpoles) and mice. This platform comprises rotors for hypergravity exposure (three aquatic rotors and one rodent rotor) and models to simulate microgravity (cages for mouse hindlimb unloading and a random positioning machine (RPM)). Four species of amphibians can be used at present. All murine strains can be used and are maintained in a specific pathogen-free area. This platform is surrounded by numerous facilities for sample preparation and analysis using state-of-the-art techniques. Finally, we illustrate how GEPAM can contribute to the understanding of molecular and cellular mechanisms and the identification of countermeasures.

Sea urchin larvae utilize light for regulating the pyloric opening.

BACKGROUND: Light is essential for various biological activities. In particular, visual information through eyes or eyespots is very important for most of animals, and thus, the functions and developmental mechanisms of visual systems have been well studied to date. In addition, light-dependent non-visual systems expressing photoreceptor Opsins have been used to study the effects of light on diverse animal behaviors. However, it remains unclear how light-dependent systems were acquired and diversified during deuterostome evolution due to an almost complete lack of knowledge on the light-response signaling pathway in Ambulacraria, one of the major groups of deuterostomes and a sister group of chordates. RESULTS: Here, we show that sea urchin larvae utilize light for digestive tract activity. We found that photoirradiation of larvae induces pyloric opening even without addition of food stimuli. Micro-surgical and knockdown experiments revealed that this stimulating light is received and mediated by Go(/RGR)-Opsin (Opsin3.2 in sea urchin genomes) cells around the anterior neuroectoderm. Furthermore, we found that the anterior neuroectodermal serotoninergic neurons near Go-Opsin-expressing cells are essential for mediating light stimuli-induced nitric oxide (NO) release at the pylorus. Our results demonstrate that the light>Go-Opsin>serotonin>NO pathway functions in pyloric opening during larval stages. CONCLUSIONS: The results shown here will lead us to understand how light-dependent systems of pyloric opening functioning via neurotransmitters were acquired and established during animal evolution. Based on the similarity of nervous system patterns and the gut proportions among Ambulacraria, we suggest the light>pyloric opening pathway may be conserved in the clade, although the light signaling pathway has so far not been reported in other members of the group. In light of brain-gut interactions previously found in vertebrates, we speculate that one primitive function of anterior neuroectodermal neurons (brain neurons) may have been to regulate the function of the digestive tract in the common ancestor of deuterostomes. Given that food consumption and nutrient absorption are essential for animals, the acquirement and development of brain-based sophisticated gut regulatory system might have been important for deuterostome evolution.

Assessment of the potential of non-thermal atmospheric pressure plasma discharge and microwave energy against Tribolium castaneum and Trogoderma granarium.

This study was carried out to investigate the efficacy of the non-thermal atmospheric pressure plasma produced with dielectric barrier discharge (APPD) using air as a processing gas and microwave energy to control Tribolium castaneum and Trogoderma granarium adults and larvae in wheat grains. Insects' mortality was found to be power and time-dependent. The results indicated that non-thermal APPD and the microwave have enough insecticidal effect on the target pests. From the bioassay, LT50's and LT90's levels were estimated, T. granarium larvae appeared more tolerant to non-thermal APPD and the microwave energy than adults 7 days post-exposure. The germination percentage of wheat grains increased as the time of exposure to the non-thermal APPD increased. On the contrary, the germination percentage of wheat grains decreased as the time of exposure to the microwave increased. In addition, changes in antioxidant enzyme activities, catalase (CAT), glutathione S-transferase (GST) and peroxidase, in adults and larvae were examined after 24 h post-treatment to non-thermal APPD at 15.9 W power level, which caused 50% mortality. The activity of CAT, GST and lipid peroxide in the treated larvae showed a significant increase post-exposure to the non-thermal APPD at 15.9 W power level. On the other hand, no significant change in GSH-Px activity was observed. Reductions in the level of glutathione (GSH) and protein content occurred in treated larvae in comparison with the control.

Application of heavy-ion-beam irradiation to breeding large rotifer.

In larviculture facilities, rotifers are generally used as an initial food source, while a proper size of live feeds to connect rotifer and Artemia associated with fish larval growth is needed. The improper management of feed size and density induces mass mortality and abnormal development of fish larvae. To improve the survival and growth of target larvae, this study applied carbon and argon heavy-ion-beam irradiation in mutation breeding to select rotifer mutants with larger lorica sizes. The optimal irradiation conditions of heavy-ion beam were determined with lethality, reproductivity, mutant frequency, and morphometric characteristics. Among 56 large mutants, TYC78, TYC176, and TYA41 also showed active population growth. In conclusion, (1) heavy-ion-beam irradiation was defined as an efficient tool for mutagenesis of rotifers and (2) the aforementioned 3 lines that have larger lorica length and active population growth may be used as a countermeasure of live feed size gap during fish larviculcure.