Gryllus Bimaculatus Research Articles

Sexual Dimorphism in Shape and Distribution of GABA-Like Immuno-Reactive Neurons in Cricket Terminal Abdominal Ganglion

We studied age-related sexual dimorphism of the terminal abdominal ganglion in the cricket, Gryllus bimaculatus using osmium/ethyl-gallate staining and GABA immunohistochemistry. We determinedthat the volume of the terminal abdominal ganglion increases with increasing body size. The growth ratio between longitude and width in the terminal abdominal ganglion is the same in all nymph stages and sexes. However, the longitudinal growth of the male terminal abdominal ganglion ceases in the 8th instar and the adult stage. Therefore, in the adult stage, sexual dimorphism is observed in ganglion morphology. Additionally, sexual dimorphism is also observed in numbers of neuronal somata and GABA-like immunoreactive neurons in the terminal abdominal ganglion. At the beginning of the 8th instar, the number of somata is greater in female crickets than in males. GABA-like immunoreactive neurons, which were classified into eight clusters, increased between the 8th instar and adult in both sexes, but their numbers were sexually dimorphic in the 7th and 8th instars, and in the adult. Females had a greater number of GABA-like immunoreactive neurons than males. These differences occurred mainly in the 8th neuromere cluster, as well as the anterior region of the 9-11th neuromeres.

EGF Signaling and the Origin of Axial Polarity among the Insects

The eggs of insects are unusual in that they often have bilateral symmetry when they are laid, indicating that both anterior-posterior (AP) and dorsal-ventral (DV) symmetries are broken during oogenesis. The molecular basis of this process is well understood in Drosophila melanogaster, in which symmetry breaking events for both axes depend on the asymmetric position of the oocyte nucleus and on germline-soma signaling mediated by the Tgf alpha-like epidermal growth factor (EGF) ligand Gurken. Germline-soma signaling interactions centered around the oocyte nucleus have been proposed in other insect species, but the molecular nature of these interactions has not been elucidated. We have examined the behavior of the oocyte nucleus and the function of EGF signaling components in the ovaries of the wasp Nasonia vitripennis, the beetle Tribolium castaneum, and the cricket Gryllus bimaculatus. We have found that EGF signaling has broadly conserved roles in mediating the encapsulation of oocytes by the somatic follicle cell layer, in establishing polarity of the egg chambers, and in setting up the DV axis of the embryo. These results provide insights into the evolutionary origins of the unique strategy employed by insects to establish embryonic axial polarity during oogenesis.

Circadian oscillations outside the optic lobe in the cricket Gryllus bimaculatus

Although circadian rhythms are found in many peripheral tissues in insects, the control mechanism is still to be elucidated. To investigate the central and peripheral relationships in the circadian organization, circadian rhythms outside the optic lobes were examined in the cricket Gryllus bimaculatus by measuring mRNA levels of period ( per) and timeless ( tim) genes in the brain, terminal abdominal ganglion (TAG), anterior stomach, mid-gut, testis, and Malpighian tubules. Except for Malpighian tubules and testis, the tissues showed a daily rhythmic expression in either both per and tim or tim alone in LD. Under constant darkness, however, the tested tissues exhibited rhythmic expression of per and tim mRNAs, suggesting that they include a circadian oscillator. The amplitude and the levels of the mRNA rhythms varied among those rhythmic tissues. Removal of the optic lobe, the central clock tissue, differentially affected the rhythms: the anterior stomach lost the rhythm of both per and tim; in the mid-gut and TAG, tim expression became arrhythmic but per maintained rhythmic expression; a persistent rhythm with a shifted phase was observed for both per and tim mRNA rhythms in the brain. These data suggest that rhythms outside the optic lobe receive control from the optic lobe to different degrees, and that the oscillatory mechanism may be different from that of Drosophila.

Age-dependent cyclic locomotor activity in the cricket, Gryllus bimaculatus, and the effect of adipokinetic hormone on locomotion and excitability

Excitability and locomotor activity of male and female last instar larvae and adults of the two-spotted cricket are measured under crowded conditions, allowing the animals to interact with conspecifics during observations. Male and female last instar larvae display age-dependent cyclic patterns of activity with maxima during early to mid scotophase and minima during early photophase. A period of low locomotor activity without time of day-dependent cyclic changes starts 1 day before the final moult and lasts until 1 day after the moult. Then, both excitability and locomotor activity increase and become cyclic again within 2 or 3 days. The cyclic changes gradually dampen in adult females older than 6 days and finally cease. When injected into photophase larvae and adults, adipokinetic hormone (AKH) increases excitability and locomotor activity in a dose-dependent manner, whereas it has no such effect when injected into scotophase animals. Other behaviours (jumping, hind wing trembling) that mostly occur in scotophase crickets are also increased by injecting AKH into photophase crickets. We argue that AKH could be responsible for linking the endogenous clock output with the cyclic changes in locomotor activity. Furthermore, AKH may serve to synchronise metabolism and behaviour to optimise larval development and reproduction.

Plasticity of the phonotactic selectiveness of four species of chirping crickets (Gryllidae): Implications for call recognition

Earlier studies of phonotaxis by female crickets describe this selective behavioural response as being important in the females' choices of conspecific males, leading to reproduction. In the present study, moderate (30+) to very large data sets of phonotactic behaviour by female Acheta domesticus L., Gryllus bimaculatus DeGeer, Gryllus pennsylvanicus Burmeister and Gryllus veletis Alexander demonstrate substantially greater plasticity in the behavioural choices, as made by females of each species, for the syllable periods (SP) of model calling songs (CS) than has been previously described. Phonotactic choices by each species range from the very selective (i.e. responding to only one or two SPs) to very unselective (i.e. responding to all SPs presented). Some females that do not respond to all SPs prefer a range that includes either the longest or shortest SP tested, which fall outside the range of SPs produced by conspecific males. Old female A. domesticus and G. pennsylvanicus are more likely to be unselective for SPs than are young females. Each species includes females that do not respond to a particular SP when responding to CSs with longer and shorter SPs. The results suggest that the plasticity of phonotactic behaviour collectively exhibited by the females of each species does not ensure that choices of a male's CS effectively focus the female's phonotactic responses on CSs that represent the conspecific male. The phonotactic behaviour collectively exhibited by females of each species does not readily fit any of the models for selective processing by central auditory neurones that have been proposed to underlie phonotactic choice.

Food intake, digestive enzyme activity and contraction of the gut is regulated by sulfakinins from the cricket Gryllus bimaculatus

Event Abstract Back to Event Food intake, digestive enzyme activity and contraction of the gut is regulated by sulfakinins from the cricket Gryllus bimaculatus Martina Meyering-Vos1*, Sandra Diersch1, Reinhard Predel2 and Joseph Woodring1 1 University of Bayreuth, Animal Ecology I, Germany 2 University of Jena, Institute of Zoology, Germany In vertebrates, a variety of mechanisms are involved in the regulation of food intake and energy balance, and recent developments in insect research indicate that the endocrine regulation of these processes in invertebrates is at least as complex. Sulfakinins (SK) are neuropeptides structurally displaying sequence homology with the hormonally active portion of the vertebrate gastrin/CCK peptide family. In Gryllus bimaculatus two sulfakinins (I, II) are encoded on the gene and the peptides could be identified in brain extracts from adult females by mass spectrometry analysis. In Gryllus bimaculatus after in vivo degradation of the specific sulfakinin mRNAs by the RNA interference method, the expression is reduced and this leads to a drastic increase in the food-intake indicating the inhibitory bioactivity of the peptides. Synthetic SK I peptide has a stimulatory effect on the release of α-amylase activity in the ventriculus, whereas SK II stimulates the release of this enzyme in the caecum of unfed crickets. Additionally, the sulfakinins stimulate the release of proteases into the caecum. SK I stimulates trypsin release and in a similar manner as gastrin stimulates biosynthesis in vertebrates. SK II increases most specifically the released aminopeptidase activity. Finally, SK I stimulates the myoactivity of the crop, wheras SK II has no effect. Acknowledgements This work was supported by the DFG Me 2034/1-3. Keywords: amylase, food intake regulation, Gastrointestinal System, gut myoactivity, Neuropeptide, Protease, satiety, Sulfakinin Conference: 25th Conference of the European Comparative Endocrinologists, Pécs, Hungary, 31 Aug - 4 Sep, 2010. Presentation Type: Conference Presentation Topic: Comparative endocrinology Citation: Meyering-Vos M, Diersch S, Predel R and Woodring J (2010). Food intake, digestive enzyme activity and contraction of the gut is regulated by sulfakinins from the cricket Gryllus bimaculatus. Front. Endocrinol. Conference Abstract: 25th Conference of the European Comparative Endocrinologists. doi: 10.3389/conf.fendo.2010.01.00081 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 10 Sep 2010; Published Online: 13 Sep 2010. * Correspondence: Dr. Martina Meyering-Vos, University of Bayreuth, Animal Ecology I, Bayreuth, Germany, martina.meyering-vos@uni-bayreuth.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Martina Meyering-Vos Sandra Diersch Reinhard Predel Joseph Woodring Google Martina Meyering-Vos Sandra Diersch Reinhard Predel Joseph Woodring Google Scholar Martina Meyering-Vos Sandra Diersch Reinhard Predel Joseph Woodring PubMed Martina Meyering-Vos Sandra Diersch Reinhard Predel Joseph Woodring Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

NO-cGMP signaling is involved in age-related memory impairment in the cricket Gryllus bimaculatus

NO-cGMP signaling is involved in age-related memory impairment in the cricket Gryllus bimaculatus

Two matched filters and the evolution of mating signals in four species of cricket

BackgroundMale field crickets produce pure-tone calling songs to attract females. Receivers are expected to have evolved a "matched filter" in the form of a tuned sensitivity for this frequency. In addition, the peripheral directionality of field crickets is sharply tuned as a result of a pressure difference receiver. We studied both forms of tuning in the same individuals of four species of cricket, where Gryllus bimaculatus and G. campestris are largely allopatric, whereas Teleogryllus oceanicus and T. commodus occur also sympatrically.ResultsThe sharpness of the sensitivity filter is highest for T. commodus, which also exhibits low interindividual variability. Individual receivers may also vary strongly in the best frequency for directional hearing. In G. campestris, such best frequencies occur even at frequencies outside the range of carrier frequencies of males. Contrary to the predictions from the "matched filter hypothesis", in three of the four species the frequency optima of the two involved filters are not matched to each other, and the mismatch can amount to 1.2 kHz. The mean carrier frequency of the male population is between the frequency optima of both filters in three species. Only in T. commodus we found a match between both filters and the male carrier frequency.ConclusionOur results show that a mismatch between the sensitivity and directionality tuning is not uncommon in crickets, and an observed match (T. commodus) appears to be the exception rather than the rule. The data suggests that independent variation of both filters is possible. During evolution each sensory task may have been driven by independent constraints, and may have evolved towards its own respective optimum.

Walking in Fourier’s space: algorithms for the computation of periodicities in song patterns by the cricket Gryllus bimaculatus

Is discrimination of the envelope of an acoustic signal based on spectral or temporal computations? To investigate this question for the cricket Gryllus bimaculatus, pattern envelopes were constructed by the addition of several sine waves and modified by systematic phase changes. The phonotactic response of female crickets towards such sinusoidal but also rectangular pulse patterns was quantified on a locomotion compensator. Envelope patterns that exhibited a modulation frequency of 25 Hz as the dominant frequency were attractive and although changes of phase modified the temporal pattern, the values of attractiveness remained unaffected. Removal of the 25-Hz component reduced the phonotactic scores. Patterns in which other frequency components exhibited a larger amplitude than the 25-Hz component were less attractive. However, the combination of an unattractive pulse period with the attractive modulation frequency of 25 Hz in a pattern revealed that such stimuli were unattractive despite the presence of the 25-Hz component. A comparison of the attractiveness of all patterns revealed that female crickets evaluated the duration of pulse period over a wide range of duty cycles. The combined evidence showed that pattern envelopes were processed in the time- and not in the spectral domain.

Development of a rapid and sensitive battery of bioassays for risk assessment of cyanobacterial microcystin-LR in drinking water of rural water treatment plants, South Africa

Due to the lack of toxin standards and resource limitations for wide scale use of analytical methods for e.g. high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) in cyanobacterial toxin monitoring, it has become necessary to assess and develop additional methods that are rapid, yet realistic and cheap for the detection of cyanobacterial toxins in drinking water of rural conventional water treatment plants in South Africa. A well-known cyanobacterial secondary metabolite (microcystin-LR) which is the dominant cyanotoxin variant in South African surface waters was tested for its adverse effect on the macrophyte plant Spirodela punctata (duckweed) and the insects Periplanetaamericana (American cockroach), Tenebrio molitar (yellow mealworm), Gryllus bimaculatus (common cricket) as well as the crustacean zooplankton (Artemia salina). In this study Gryllus bimaculatus and Artemia salina LD50 body weight values were calculated as 0.45 µg/animal and 0.1 µg/animal, respectively, within the first 48 h after exposure to microcystin-LR. These values obtained indicate that sensitivities of G. bimaculatus and A. salina to low concentrations of microcystin-LR were comparable to the mouse bioassay. No mortalities of P. americana and T. molitar were observed after 48 h of exposure to different concentrations of synthetic microcystin-LR (0.5, 1.0, 5.0 µg/L). Moreover, on sub-organism or cellular level, DNA fragmentation occured in P. americana, T. molitar, A. salina and G. bimaculatus within the first 48 h after exposure to synthetic microcystin-LR. Although the ease of culturing of the American cockroach and yellow mealworm make them ideal organisms to be included in a battery of bioassays, their 48 h LD50non-response on organism level to low concentrations of microcystin exclude these species from a rapid sensitive battery of bioassays. From the data generated in this study the 5 day Spirodela punctata bioassay was the most sensitive bioassay by showing reduction of root growth and fronds weight as well as changes in the chlorophyll a and b ratio content within the first 12 h after exposure to a low concentration (0.1 µg/L) of synthetic microcystin-LR. Key words: Battery of bioassays, microcystin-LR, apoptosis, chlorosis, Spirodela punctata.

19-P009 Regulation of leg size and shape by the Dachsous/Fat signalling pathway during regeneration in Gryllus bimaculatus

19-P009 Regulation of leg size and shape by the Dachsous/Fat signalling pathway during regeneration in Gryllus bimaculatus

Calling and Courtship Behaviors Initiated by Male-Male Contact Via Agonistic Encounters in the CricketGryllus bimaculatus

We investigated the stridulatory courtship initiated by male-male contact after agonistic encounters and the effect of dominance status on subsequent reproductive behavior in the cricket Gryllus bimaculatus. When two male crickets were kept together in a small area, their dominance status was quickly established through fighting or non-fighting interactions. Approximately 10 min after pairing, most dominant males produced calling and/or courtship songs in the presence of subordinate males. This behavior appeared to be triggered by some contact chemicals on the body surface of the males. Stimulation using the forewing of a neutral male induced courtship in dominant males at a higher level compared with neutral males which were not previously paired with males. These observations suggest that the sexual motivation in dominant males increased because of previous agonistic interactions. In contrast, subordinate males remained silent. Stimulation using the male forewing induced stridulation to a lesser degree in subordinate males than in neutral males, suggesting decreased sexual motivation in subordinate males. Furthermore, only 40% of subordinate males exhibited courtship behavior under triadic conditions (dominant male, subordinate male and female) in contrast with 100% in male-female pairs. This result reveals that subordinate males, being less sexually motivated, are continuously suppressed in their courtship by intermittent attacks by the nearby dominant males. In the other triadic condition where the males were allowed to copulate, 65% of the dominant males copulated, while none of the subordinates did. These results suggest that dominant males have a greater chance to copulate and produce offspring.

19-P011 Involvement of the Hedgehog/Engrailed signaling in regeneration of the posterior structures in the amputated leg of the cricket Gryllus bimaculatus

19-P011 Involvement of the Hedgehog/Engrailed signaling in regeneration of the posterior structures in the amputated leg of the cricket Gryllus bimaculatus

The intensity of pre- and post-copulatory mate guarding in relation to spermatophore transfer in the cricket Gryllus bimaculatus

While post-copulatory mate guarding has been well documented in field crickets (Orthoptera: Gryllidae), the occurrence of pre-copulatory mate guarding in this family has been largely overlooked. We examined the relationship between the intensity of two components of mate guarding (body judders and antennal whips) and the time before and after copulation. We found that when male Gryllus bimaculatus encounter a female but do not have a spermatophore ready to transfer, they engage in pre-copulatory mate guarding that is very similar to post-copulatory mate guarding. The intensity of pre-copulatory mate guarding increased up to the point at which the male was ready to transfer his spermatophore. Following copulation, the intensity of mate guarding initially remained high before declining, after which it began to increase again just before the male resumed courtship stridulation. We interpret this pattern of post-copulatory mate guarding as being consistent with both the ejaculate-protection and spermatophore-renewal hypotheses for the function of mate guarding. We found no significant relationship between mate guarding intensity and male body mass.

There will be blood: autohaemorrhage behaviour as part of the defence repertoire of an insect

AbstractArmoured ground crickets Acanthoplus discoidalis (Bradyporidae) have an arsenal of defence mechanisms in response to attack. Males but not females can stridulate when attacked, while both sexes will bite and regurgitate upon provocation. They will also autohaemorrhage. Here we have quantified these responses, examining how individuals of both sexes respond to repeated simulated predatory attack from the side (grabbing the legs with forceps) or from above (grabbing the animal by the pronotum). We found different responses depending on the method of attack. When attack was directed from the side (at the legs) the crickets can bite their attacker and males stridulate intensely. About 62% of such attacks elicited an autohaemorrhage response, where the crickets squirt 13±22 mg of acrid‐smelling haemolymph 43±63 mm from seams in the connective tissue between the trochanter and coxa of each leg and from under the pronotum. By contrast, animals attacked from above could not turn and bite their attacker, and stridulation was also reduced in males. About 86% of such attacks elicited an autohaemorrhage response with 19±19 mg of haemolymph projecting 10±30 mm from the body. Autohaemorrhaging is an effective form of chemical defence against bearded dragon lizards Pogona vitticeps (Agamidae) and Aca. discoidalis haemolymph applied to Gryllus bimaculatus nymphs (which have no such chemical defence) successfully saved them from predation by striped skinks Trachylepis punctatissima (Scincidae).

Loss‐of‐function analyses of the fragile X‐related and dopamine receptor genes by RNA interference in the cricket Gryllus bimaculatus

In order to explore a possibility that the cricket Gryllus bimaculatus would be a useful model to unveil molecular mechanisms of human diseases, we performed loss-of-function analyses of Gryllus genes homologous to human genes that are responsible for human disorders, fragile X mental retardation 1 (fmr1) and Dopamine receptor (DopR). We cloned cDNAs of their Gryllus homologues, Gb'fmr1, Gb'DopRI, and Gb'DopRII, and analyzed their functions with use of nymphal RNA interference (RNAi). For Gb'fmr1, three major phenotypes were observed: (1) abnormal wing postures, (2) abnormal calling song, and (3) loss of the circadian locomotor rhythm, while for Gb'DopRI, defects of wing posture and morphology were found. These results indicate that the cricket has the potential to become a novel model system to explore human neuronal pathogenic mechanisms and to screen therapeutic drugs by RNAi.

Differential gene expression during compensatory sprouting of dendrites in the auditory system of the cricketGryllus bimaculatus

Neurones that lose their presynaptic partners because of injury usually retract or die. However, when the auditory interneurones of the cricket Gryllus bimaculatus are denervated, dendrites respond by growing across the midline and forming novel synapses with the opposite auditory afferents. Suppression subtractive hybridization was used to detect transcriptional changes 3 days after denervation. This is a stage at which we demonstrate robust compensatory dendritic sprouting. Whereas 49 unique candidates were down-regulated, no sufficiently up-regulated candidates were identified at this time point. Several candidates identified in this study are known to influence the translation and degradation of proteins in other systems. The potential role of these factors in the compensatory sprouting of cricket auditory interneurones in response to denervation is discussed.

PERTUMBUHAN TIGA SPESIES JANGKRIK LOKAL YANG DIBudidaya KAN PADA PADAT PENEBARAN DAN JENIS PAKAN BERBEDA

In the development of cricket farming, important information in regard with cultivated method, type of crickets, feedstuff, density level, and it’s productivity is essential. The aim of this study was to evaluate the effects of different density level and rations on growth performace of three species of local crickets, i.e Gryllus bimaculatus De Geer, Gryllus mitratus Burn and Gryllus testaceus Walk. Three levels of box square density (500, 750 and 1000 cricket/box) and two levels of additional feed (mustard green and papaya leaves) were used as treatments. The results showed that the density level of approximately 1000 cricket/box had no significant influence on growth performance of the three species local crickets. Nevertheless, higher density level tended to increase mortality rate especially for G. bimaculatus (rate of mortality = 45.86%). The use of feed combination of formulated ration plus mustard green resulted in better growth performance and higher egg production compared to the combination of formulated ration plus papaya leaves.

Role of allatostatin‐like factors from the brain of Tenebrio molitor females

The effect of brain extract from females of freshly emerged Tenebrio molitor on ovary, oocyte development, total protein content of hemolymph, and ovary was studied in 4-day-old adult mealworm females. Injections of extracts of 2-brain equivalents into intact (unligatured) Tenebrio females did not affect ovarian and oocyte development. Injections of ligated females, however, with 2-brain equivalents on day 1 and 2 after adult emergence strongly inhibited ovarian growth and oocyte development. At day 4, ligated and injected females did not develop their ovaries and pre-vitellogenic oocytes were not found. The changes in ovarian development correlated with an increase in the concentration of soluble proteins in the hemolymph as compared with the saline-injected controls. Additionally, a strong reduction of total protein content in ovarian tissue was observed. Reverse phase HPLC separation of a methanolic brain extract of T. molitor females showed that fraction 5 has a similar retention time to synthetic cockroach allatostatin. Fraction 5 was eluted at 12.88 min, which was closest to the internal standard Dippu-AST I, which eluted at 12.77 min. An ELISA of fraction 5 from the methanolic brain extract using antibodies against allatostatins Grybi-AST A1 and Grybi-AST B1 from cricket Gryllus bimaculatus showed that fraction 5 cross-reacted with Grybi-AST A1 antibodies. The cross-reactivity was similar to the synthetic allatostatin from D. punctata, which was used as a positive control. These observations demonstrate a possible role for allatostatin-like brain factor(s) in regulating the reproductive cycle of Tenebrio molitor.

Mate choice in field crickets: can females acoustically detect male body size?

Females can potentially choose high-quality males by evaluating male secondary sexual traits such as acoustic signals. In field crickets (Orthoptera: Gryllidae), body size is thought to indicate male quality. Song carrier frequency (FQ) has been suggested to indicate male body size because the areas of the wing that control FQ (harp) scale with body size. However, no direct evidence showing that males can advertise their size via FQ exists for grylline crickets. Firstly, we show the lack of evidence indicating a clear relationship between FQ and body size for grylline crickets by conducting a literature review. We then calculate the three-way relationship between body size, harp size and FQ and show no relationship between FQ and body size for Gryllus bimaculatus. Eight other commonly measured song parameters also failed to indicate body size. Individual female preference functions for FQ are calculated and we demonstrate that females cannot select large males on the basis of FQ. Furthermore, we demonstrate that variation in male FQ falls within the range of female preference at the population level. Females probably cannot evaluate male body size based on the temporal and spectral properties of male calling song and alternative avenues of study are suggested.