| cytochrome p450 family 4 in a cockroach: molecular cloning and regulation by regulation by hypertrehalosemic hormone. | hypertrehalosemic hormone (a carbohydrate-mobilizing neuroendocrine decapeptide) and starvation markedly increased levels of a cockroach (blaberus discoidalis) fat body cytochrome p450 message. the gene represented by the cloned p450 cdna has been named cyp4c1 (cytochrome p450 family 4, subfamily c, gene 1), a newly identified member of the ubiquitous cytochrome p450 monooxygenase gene superfamily. blaberus cyp4c1 (511 amino acids, mr = 58,485) has a hydrophobic nh2 terminus and a sequence near ... | 1991 | 2034694 |
| characterisation of neuropeptides of the akh/rpch-family from corpora cardiaca of coleoptera. | extracts of corpora cardiaca from two members of the family tenebrionidae. zophobas rugipes and tenebrio molitor, from one member of the chrysomelidae, leptinotarsa decemlineata, and from three members of the scarabaeidae, pachnoda marginata, p. sinuata and melolontha hippocastani, were assayed for adipokinetic and hypertrehalosaemic activity in acceptor locusts (locusta migratoria) and cockroaches (periplaneta americana), respectively. all corpus cardiacum material tested, except that from the ... | 1989 | 2607020 |
| the hypertrehalosaemic peptides of cockroaches: a phylogenetic study. | hypertrehalosaemic peptides from the corpora cardiaca of 14 different species were compared with respect to phylogenetic relationships within the insect suborder blattaria (cockroaches). gland extracts from members of the family blattidae (periplaneta americana, p. brunnea, p. australasiae, p. fuliginosa, and blatta orientalis) contain two hypertrehalosaemic octapeptides with identical properties to the recently sequenced peptides m i and m ii from the american cockroach, whereas corpora cardiac ... | 1989 | 2806876 |
| cyclophilin: distribution and variant properties in normal and neoplastic tissues. | the cytosolic concentration, mr, and isoforms of cyclophilin (cyp), a specific cytosolic binding protein for cyclosporin a (csa), were determined in normal and neoplastic human tissues as well as tissues from species of diverse phylogeny. cyp was present in all tissues examined; however, concentrations varied significantly among different tissue types. the cyp concentration was highest in lymphoblasts from a patient with t cell acute lymphocytic leukemia (1.15 micrograms/mg protein) and hodgkin' ... | 1986 | 3522735 |
| characterization of the adipokinetic hormone receptor form the fat body of manduca sexta. | a tritium labeled manduca sexta adipokinetic hormone (m-akh) was synthesized (pe-l-t-[p3h]f-t-s-s-w-g-nh2) (specific activity 27 ci/mmol) which was fully active in a bioassay. it was used in a filtration based binding assay to characterize the m-akh receptor from the fat body of m. sexta. membrane fractions were prepared from fat body and optimal binding conditions were determined. a kd of 7.10(-10) m was determined and the receptor concentration estimated to be 0.5 pmol/mg membrane protein. no ... | 1995 | 7480882 |
| transferrin in a cockroach: molecular cloning, characterization, and suppression by juvenile hormone. | in a study of juvenile hormone-regulated gene expression, we isolated an anonymous cdna representing a message that was strongly suppressed by juvenile hormone in the fat body of the cockroach blaberus discoidalis. the protein deduced from the cdna sequence showed compelling resemblance in sequence to the transferrins, a superfamily of internally duplicated, 80-kda iron-binding/transport proteins characterized from several vertebrates and, to date, one insect (the tobacco hornworm, manduca sexta ... | 1993 | 7679500 |
| the detection of akh/hrth-like peptides in ascaridia galli and ascaris suum using an insect hyperglycaemic bioassay. | evidence for the presence of adipokinetic hormone/hypertrehalosaemic hormone (akh/hrth)-like peptides in the parasitic nematodes ascaridia galli and ascaris suum has been obtained using insect bioassays which measure hyperglycaemic responses to peptides belonging to the akh/hrth family of insect hormones. a peptide fraction extracted from heads and tails of ascaridia galli evoked a dose-dependent hyperglycaemic response when injected into the cockroach, periplaneta americana. maximal bioactivity ... | 1994 | 8008462 |
| detection, isolation and characterization of multiple lectins from the haemolymph of the cockroach blaberus discoidalis. | three agglutinins (lectins), designated bdl1, bdl2 and bdl3, were identified in the haemolymph of the cockroach blaberus discoidalis by erythrocyte cross-adsorption and sugar inhibition tests. with the use of (nh4)2so4 fractionation, anion-exchange and affinity chromatography, bdl1 and bdl2 have been purified to homogeneity, and bdl3 has been partially purified to three bands on sds/page. bdl1 has a molecular-mass estimate of 390 kda by gel filtration and approx. 158 kda by sds/page under non-re ... | 1993 | 8363570 |
| cockroach transferrin closely resembles vertebrate transferrins in its metal ion-binding properties: a spectroscopic study. | the optical and electron paramagnetic resonance (epr) spectroscopic properties of a transferrin from the cockroach blaberus discoidalis have been investigated to determine the relation of this protein to vertebrate transferrins. difference spectrophotometry substantiates the involvement of tyrosyl residues in iron binding, and confirms the specific binding of two equivalents of iron per molecule. the far-uv cd spectrum also indicates a secondary structure with marked similarity to those of verte ... | 1996 | 8916413 |
| isolation and identification of a cytochrome p450 sequence in an australian termite, mastotermes darwiniensis. | a partial cytochrome p450 sequence was rt/pcr amplified from total rna isolated from the whole body of worker class termites (mastotermes darwiniensis). the degenerate primers used were designed from conserved regions from 4 different species: rat, human, cockroach and drosophila. the sequence was defined by the presence of the typical p450 heme-binding region and invariant residues found in all p450 proteins. the deduced amino acid sequence is 67% identical to cockroach (blaberus discoidalis) c ... | 1997 | 9425314 |
| innate immunity in insects: the role of multiple, endogenous serum lectins in the recognition of foreign invaders in the cockroach, blaberus discoidalis. | unlike vertebrates, insects do not have an ab-based nonself recognition system, and must rely totally on innate immunity to defend themselves from microbial invaders. the most likely candidates for recognizing foreign material in insects are the lectins, which have already been shown to be important in mammalian innate immunity. the hemolymph of the cockroach, blaberus discoidalis, contains multiple lectins, designated bdl1, bdl2, bdl3, and gsl (beta-1,3-glucan-specific lectin), two of which, na ... | 1999 | 9973417 |
| identification and characterisation of a cytochrome p450 gene and processed pseudogene from an arachnid: the cattle tick, boophilus microplus. | we isolated and sequenced the first known cytochrome p450 gene and pseudogene from an arachnid, the cattle tick, boophilus microplus. both the gene and pseudogene belong to the family cyp4, but a new subfamily, cyp4w, had to be created for these genes because they are substantially different to other cyp4 genes. the gene, cyp4w1, has greatest homology with cyp4c1 from a cockroach, blaberus discoidalis. the predicted molecular weight of the protein encoded by cyp4w1 (63 kda) is greater than that ... | 1999 | 10333575 |
| identification, purification and properties of a beta-1,3-glucan-specific lectin from the serum of the cockroach, blaberus discoidalis which is implicated in immune defence reactions. | a lectin specific for laminarin, a beta-1,3-glucan, agglutinating baker's yeast and enhancing prophenoloxidase activation by laminarin, has been purified from the cockroach, blaberus discoidalis, serum. purification involved gel filtration with bio-gel p300 and affinity chromatography on blue sepharose cl-6b and laminarin-sepharose 4b. the purified lectin has a molecular mass estimate of 520 kda determined by gel filtration, and approximately 80 and 82 kda by sds-page, under non-reducing and red ... | 1999 | 10374258 |
| detection and characterization of a mannan-binding lectin from the mosquito, anopheles stephensi (liston). | two lectins from the serum of the mosquito, anopheles stephensi (liston), with distinct characteristics, were detected by agglutination of various animal erythrocytes. the lectins were developmental stage-specific and/or sex-related. one adult female-specific lectin was identified as mannan-specific, and named mosquito mannan-binding lectin (mbl). mbl cross-reacted immunologically with antibodies against a previously characterized cockroach lectin, blaberus discoidalis lectin (bdl1), and its act ... | 1999 | 10406943 |
| effect of lysozyme on the lectin-mediated phagocytosis of bacillus cereus by haemocytes of the cockroach, blaberus discoidalis. | lysozyme-like activity has been demonstrated in both cell-free haemolymph and, more abundantly, in haemocyte-lysate supernatants of blaberus discoidalis. this activity was non-inducible, but heat-stable, with a maximum activity at ph 6.2. when b. cereus was pre-incubated in a concentration of chicken egg-white lysozyme equivalent to the concentration of lysozyme-like activity in cell-free haemolymph, the phagocytosis of b. cereus opsonized with glcnac-specific lectins, i.e. bdl2, wga and hpa, wa ... | 2000 | 10742514 |
| a juvenile hormone-repressible transferrin-like protein from the bean bug, riptortus clavatus: cdna sequence analysis and protein identification during diapause and vitellogenesis. | we found several juvenile hormone-responsive cdnas in the bean bug, riptortus clavatus, by using mrna differential display (hirai et al., 1998). one of them, a juvenile hormone-repressible cdna, jr-3, was cloned, sequenced, characterized and identified as a transferrin (rctf). rctf cdna encoded 652 amino acids with a calculated molecular weight of 71,453 da. the deduced amino acid sequence showed significant homology with the transferin genes of several insects, manduca sexta (43% identity), bla ... | 2000 | 10790182 |
| efficacy of oral sulfadimethoxine against two gregarine parasites, protomagalhaensia granulosae and gregarina cubensis (apicomplexa: eugregarinida), infecting the death's head cockroach, blaberus discoidalis. | gregarines are common parasites of insects in culture, but no effective chemotherapeutic or prophylactic control protocol has been demonstrated. sulfadimethoxine was administered in 5- and 7-day treatments to death's head cockroaches (blaberus discoidalis) infected with gregarina cubensis and protomagalhaensia granulosae to test the efficacy of this sulfonamide against gregarine infection. sulfadimethoxine significantly reduced the mean intensity of both g. cubensis and p. granulosae. sulfadimet ... | 2002 | 12197132 |
| the cockroaches blaberus craniifer and blaberus discoidalis as vectors of salmonella typhosa. | | 1959 | 13637308 |
| effects of temperature on the development of gregarina cubensis (apicomplexa: eugregarinida) parasitizing blaberus discoidalis (blattaria: blaberidae). | gregarina cubensis is an apicomplexan parasite that infects the intestinal lumen of the death's head cockroach (blaberus discoidalis). this study evaluated the effects of 3 temperatures on the development and viability of g. cubensis. three groups of b. discoidalis were inoculated with g. cubensis oocysts and maintained at 15, 27, and 40 c. the alimentary canal was removed from 3 cockroaches in each group every 24 hr until mature gametocysts were found in the rectum or feces, and prepared for hi ... | 2007 | 17626350 |
| juvenile hormone and methyl farnesoate production in cockroach embryos in relation to dorsal closure and the reproductive modes of different species of cockroaches. | juvenile hormone (jh), produced by the corpora allata (ca), is first detectable after dorsal closure, a conspicuous event in embryogenesis. the present research found that the timing of dorsal closure was consistently at about 45% of the total embryonic development time across most of the oviparous and ovoviviparous cockroach species examined. these included the ovoviviparous cockroaches blaberus discoidalis, byrsotria fumigata, rhyparobia maderae, nauphoeta cinerea, phoetalia pallida, schultesi ... | 2007 | 18000875 |
| in vitro superoxide activity in the haemolymph of the west indian leaf cockroach, blaberus discoidalis. | the respiratory burst is an nadph oxidase-driven reduction of molecular oxygen to superoxide, which can occur in phagocytic cells as part of an antimicrobial defence, and is well documented among the vertebrates. this paper describes a process resembling the respiratory burst, which occurs in the haemolymph and haemocytes of the cockroach, blaberus discoidalis. the in vitro reduction of nitroblue tetrazolium by superoxide to formazan was measured spectrophotometrically in b. discoidalis haemolym ... | 1999 | 12770352 |
| a computational model of the integration of landmarks and motion in the insect central complex. | the insect central complex (cx) is an enigmatic structure whose computational function has evaded inquiry, but has been implicated in a wide range of behaviours. recent experimental evidence from the fruit fly (drosophila melanogaster) and the cockroach (blaberus discoidalis) has demonstrated the existence of neural activity corresponding to the animal's orientation within a virtual arena (a neural 'compass'), and this provides an insight into one component of the cx structure. there are two key ... | 2017 | 28241061 |
| thought-controlled nanoscale robots in a living host. | we report a new type of brain-machine interface enabling a human operator to control nanometer-size robots inside a living animal by brain activity. recorded eeg patterns are recognized online by an algorithm, which in turn controls the state of an electromagnetic field. the field induces the local heating of billions of mechanically-actuating dna origami robots tethered to metal nanoparticles, leading to their reversible activation and subsequent exposure of a bioactive payload. as a proof of p ... | 2016 | 27525806 |
| biomechanical factors in the adaptations of insect tibia cuticle. | insects are among the most diverse groups of animals on earth. their cuticle exoskeletons vary greatly in terms of size and shape, and are subjected to different applied forces during daily activities. we investigated the biomechanics of the tibiae of three different insect species: the desert locust (schistocerca gregaria), american cockroach (periplaneta americana) and death's head cockroach (blaberus discoidalis). in a previous work, we showed that these tibiae vary not only in geometry (leng ... | 2016 | 27486904 |
| cellular basis of head direction and contextual cues in the insect brain. | animals rely upon integrated sensory information for spatial navigation. a question of wide importance in navigation is how sensory cues get transformed into neural codes that represent the animal's orientation within its proximal environment. here, we investigated the possibility of head-direction coding in the central complex of the cockroach, blaberus discoidalis. we used extracellular recordings in restrained animals that were rotated on a platform relative to a fixed landmark. the passive r ... | 2016 | 27397888 |
| leg regrowth in blaberus discoidalis (discoid cockroach) following limb autotomy versus limb severance and relevance to neurophysiology experiments. | many insects can regenerate limbs, but less is known about the regrowth process with regard to limb injury type. as part of our neurophysiology education experiments involving the removal of a cockroach leg, 1) the ability of blaberus discoidalis cockroaches to regenerate a metathoracic leg was examined following autotomy at the femur/trochanter joint versus severance via a transverse coxa-cut, and 2) the neurophysiology of the detached legs with regard to leg removal type was studied by measuri ... | 2016 | 26824931 |
| buckling failures in insect exoskeletons. | thin walled tubes are often used for load-bearing structures, in nature and in engineering, because they offer good resistance to bending and torsion at relatively low weight. however, when loaded in bending they are prone to failure by buckling. it is difficult to predict the loading conditions which cause buckling, especially for tubes whose cross sections are not simple shapes. insights into buckling prevention might be gained by studying this phenomenon in the exoskeletons of insects and oth ... | 2015 | 26678374 |
| central-complex control of movement in the freely walking cockroach. | to navigate in the world, an animal's brain must produce commands to move, change direction, and negotiate obstacles. in the insect brain, the central complex integrates multiple forms of sensory information and guides locomotion during behaviors such as foraging, climbing over barriers, and navigating to memorized locations. these roles suggest that the central complex influences motor commands, directing the appropriate movement within the current context. such commands are ultimately carried ... | 2015 | 26592340 |
| effects of developmental temperature on gametocysts and oocysts of two species of gregarines blabericola migrator and blabericola cubensis (apicomplexa: eugregarinida: blabericolidae) parasitizing blaberid cockroaches (dictyoptera: blaberidae). | abiotic environmental conditions, especially temperature and humidity, have profound effects on the growth and development of gregarines, but these effects remain largely undocumented. quantifying the effects of environmental conditions on the growth and development of exogenous gregarine ontogenetic stages is an important first step in understanding the transmission, population dynamics, and environmental persistence of gregarine infection. in this study, we examined the effect of 6 environment ... | 2015 | 26248890 |
| terradynamically streamlined shapes in animals and robots enhance traversability through densely cluttered terrain. | many animals, modern aircraft, and underwater vehicles use fusiform, streamlined body shapes that reduce fluid dynamic drag to achieve fast and effective locomotion in air and water. similarly, numerous small terrestrial animals move through cluttered terrain where three-dimensional, multi-component obstacles like grass, shrubs, vines, and leaf litter also resist motion, but it is unknown whether their body shape plays a major role in traversal. few ground vehicles or terrestrial robots have use ... | 2015 | 26098002 |
| locomotion control of hybrid cockroach robots. | natural systems retain significant advantages over engineered systems in many aspects, including size and versatility. in this research, we develop a hybrid robotic system using american (periplaneta americana) and discoid (blaberus discoidalis) cockroaches that uses the natural locomotion and robustness of the insect. a tethered control system was firstly characterized using american cockroaches, wherein implanted electrodes were used to apply an electrical stimulus to the prothoracic ganglia. ... | 2015 | 25740855 |
| encoding wide-field motion and direction in the central complex of the cockroach blaberus discoidalis. | in the arthropod brain, the central complex (cx) receives various forms of sensory signals and is associated with motor functions, but its precise role in behavior is controversial. the optomotor response is a highly conserved turning behavior directed by visual motion. in tethered cockroaches, 20% procaine injected into the cx reversibly blocked this behavior. we then used multichannel extracellular recording to sample unit activity in the cx in response to wide-field visual motion stimuli, mov ... | 2014 | 25278467 |
| universal computing by dna origami robots in a living animal. | biological systems are collections of discrete molecular objects that move around and collide with each other. cells carry out elaborate processes by precisely controlling these collisions, but developing artificial machines that can interface with and control such interactions remains a significant challenge. dna is a natural substrate for computing and has been used to implement a diverse set of mathematical problems, logic circuits and robotics. the molecule also interfaces naturally with liv ... | 2014 | 24705510 |
| a neuromechanical simulation of insect walking and transition to turning of the cockroach blaberus discoidalis. | a neuromechanical simulation of the cockroach blaberus discoidalis was developed to explore changes in locomotion when the animal transitions from walking straight to turning. the simulation was based upon the biological data taken from three sources. neural circuitry was adapted from the extensive literature primarily obtained from the studies of neural connections within thoracic ganglia of stick insect and adapted to cockroach. the 3d joint kinematic data on straight, forward walking for cock ... | 2014 | 24178847 |
| closing the loop in legged neuromechanics: an open-source computer vision controlled treadmill. | the neural circuitry that controls legged locomotion is exquisitely state dependent. the response to a perturbation at one phase of the locomotor cycle is very different from another. as such, tools that enable closed loop experiments in which freely moving animals can be precisely perturbed, either neurally or mechanically, will improve our ability to probe the locomotor control architecture. because locomotion emerges from the coupled interaction of the nervous system, musculoskeletal system, ... | 2013 | 23541994 |
| instantaneous kinematic phase reflects neuromechanical response to lateral perturbations of running cockroaches. | instantaneous kinematic phase calculation allows the development of reduced-order oscillator models useful in generating hypotheses of neuromechanical control. when perturbed, changes in instantaneous kinematic phase and frequency of rhythmic movements can provide details of movement and evidence for neural feedback to a system-level neural oscillator with a time resolution not possible with traditional approaches. we elicited an escape response in cockroaches (blaberus discoidalis) that ran ont ... | 2013 | 23371006 |
| assessment of toxicity of nanoparticles using insects as biological models. | nanomaterials have become increasingly important in medicine, manufacturing, and consumer products. the fundamental understanding in effects of nanoparticles (nps) on and their interactions with biomolecules and organismal systems have yet to be achieved. in this chapter, we firstly provide a brief review of the interactions between nanoparticles and biological systems. we will then provide an example by describing a novel method to assess the effects of nps on biological systems, using insects ... | 2012 | 22791454 |
| an implantable biofuel cell for a live insect. | a biofuel cell incorporating a bienzymatic trehalase|glucose oxidase trehalose anode and a bilirubin oxidase dioxygen cathode using os complexes grafted to a polymeric backbone as electron relays was designed and constructed. the specific power densities of the biofuel cell implanted in a female blaberus discoidalis through incisions into its abdomen yielded maximum values of ca. 55 μw/cm(2) at 0.2 v that decreased by only ca. 5% after ca. 2.5 h of operation. | 2012 | 22239249 |
| synoptic revision of blabericola (apicomplexa: eugregarinida: blabericolidae) parasitizing blaberid cockroaches (dictyoptera: blaberidae), with comments on delineating gregarine species boundaries. | complete synoptic redescriptions, including complete morphometric data for all life cycle stages, species recognition characters, and differential comparisons are presented for the 4 gregarine species comprising blabericola . blabericola cubensis ( peregrine, 1970 ), blabericola haasi (geus, 1969), blabericola migrator ( clopton, 1995 ), and blabericola princisi ( peregrine, 1970 ) are redescribed from their type hosts, i.e., the discoid cockroach blaberus discoidalis , the lobster cockroach nau ... | 2012 | 22150235 |
| kinematic and behavioral evidence for a distinction between trotting and ambling gaits in the cockroach blaberus discoidalis. | earlier observations had suggested that cockroaches might show multiple patterns of leg coordination, or gaits, but these were not followed by detailed behavioral or kinematic measurements that would allow a definite conclusion. we measured the walking speeds of cockroaches exploring a large arena and found that the body movements tended to cluster at one of two preferred speeds, either very slow (<10 cm s(-1)) or fairly fast (∼30 cm s(-1)). to highlight the neural control of walking leg movemen ... | 2011 | 21613522 |
| shifts in a single muscle's control potential of body dynamics are determined by mechanical feedback. | muscles are multi-functional structures that interface neural and mechanical systems. muscle work depends on a large multi-dimensional space of stimulus (neural) and strain (mechanical) parameters. in our companion paper, we rewrote activation to individual muscles in intact, behaving cockroaches (blaberus discoidalis l.), revealing a specific muscle's potential to control body dynamics in different behaviours. here, we use those results to provide the biologically relevant parameters for in sit ... | 2011 | 21502130 |
| a single muscle's multifunctional control potential of body dynamics for postural control and running. | a neuromechanical approach to control requires understanding how mechanics alters the potential of neural feedback to control body dynamics. here, we rewrite activation of individual motor units of a behaving animal to mimic the effects of neural feedback without concomitant changes in other muscles. we target a putative control muscle in the cockroach, blaberus discoidalis (l.), and simultaneously capture limb and body dynamics through high-speed videography and a micro-accelerometer backpack. ... | 2011 | 21502129 |
| in vivo observation of gold nanoparticles in the central nervous system of blaberus discoidalis. | nanoparticles (nps) are widely studied for biomedical applications. understanding interactions between nps and biomolecules or cells has yet to be achieved. here we present a novel in vivo method to study interactions between nps and the nervous system of the discoid or false dead-head roach, blaberus discoidalis. the aims of this study were to present a new and effective method to observe nps in vivo that opens the door to new methods of study to observe the interactions between nps and biologi ... | 2011 | 21332995 |
| insects running on elastic surfaces. | in nature, cockroaches run rapidly over complex terrain such as leaf litter. these substrates are rarely rigid, and are frequently very compliant. whether and how compliant surfaces change the dynamics of rapid insect locomotion has not been investigated to date largely due to experimental limitations. we tested the hypothesis that a running insect can maintain average forward speed over an extremely soft elastic surface (10 n m(-1)) equal to 2/3 of its virtual leg stiffness (15 n m(-1)). cockro ... | 2010 | 20472778 |
| a model for insect locomotion in the horizontal plane: feedforward activation of fast muscles, stability, and robustness. | we develop a neuromechanical model for running insects that includes a simplified hexapedal leg geometry with agonist-antagonist muscle pairs actuating each leg joint. restricting to dynamics in the horizontal plane and neglecting leg masses, we reduce the model to three degrees of freedom describing translational and yawing motions of the body. muscles are driven by stylized action potentials characteristic of fast motoneurons, and modeled using an activation function and nonlinear length and s ... | 2009 | 19660474 |
| characterization of obstacle negotiation behaviors in the cockroach, blaberus discoidalis. | within natural environments, animals must be able to respond to a wide range of obstacles in their path. such responses require sensory information to facilitate appropriate and effective motor behaviors. the objective of this study was to characterize sensors involved in the complex control of obstacle negotiation behaviors in the cockroach blaberus discoidalis. previous studies suggest that antennae are involved in obstacle detection and negotiation behaviors. during climbing attempts, cockroa ... | 2009 | 19411540 |
| improving horizontal plane locomotion via leg angle control. | the lateral leg spring model has been shown to accurately represent horizontal plane locomotion characteristics of sprawled posture insects such as the cockroach blaberus discoidalis. while passively stable periodic gaits result from employing a constant leg touch-down angle for this model, utilizing a similar protocol for a point mass model of locomotion in three dimensions produces only unstable periodic gaits. in this work, we return to the horizontal plane model and develop a simple control ... | 2009 | 18951907 |
| neuromechanical response of musculo-skeletal structures in cockroaches during rapid running on rough terrain. | a musculo-skeletal structure can stabilize rapid locomotion using neural and/or mechanical feedback. neural feedback results in an altered feedforward activation pattern, whereas mechanical feedback using visco-elastic structures does not require a change in the neural motor code. we selected musculo-skeletal structures in the cockroach (blaberus discoidalis) because their single motor neuron innervation allows the simplest possible characterization of activation. we ran cockroaches over a track ... | 2008 | 18203999 |
| multi-unit recording of antennal mechano-sensitive units in the central complex of the cockroach, blaberus discoidalis. | the central complex (cc) is a group of midline neuropils in the protocerebrum of all insects (williams, j zool, 176:67-86, 1975; strausfeld, prog brain res, 123:273-284, 1999). its columnar organization coupled with the anatomical tracts to and from this region suggests that the cc may supervise various forms of locomotion. in cockroach, lesions of the cc affect turning and controlled climbing over blocks (ridgel et al., j comp physiol a, 193:385-402, 2007). since these behaviors are largely dir ... | 2008 | 18180927 |
| a hexapedal jointed-leg model for insect locomotion in the horizontal plane. | we develop a simple model for insect locomotion in the horizontal (ground) plane. as in earlier work by seipel et al. (biol cybern 91(0):76-90, 2004) we employ six actuated legs that also contain passive springs, but the legs, with "hip" and 'knee' joints, better represent insect morphology. actuation is provided via preferred angle inputs at each joint, corresponding to zero torques in the hip and knee springs. the inputs are determined from estimates of foot forces in the cockroach blaberus di ... | 2007 | 17926063 |
| descending control of turning behavior in the cockroach, blaberus discoidalis. | legged locomotion has evolved as the most effective form of movement through unpredictable and tortuous environments. upon encountering an obstacle, an animal must evaluate the object with its sense organs then use the information it acquires to direct appropriate transitional behaviors, such as turning. previous studies using genetic and surgical lesions implicate the central body complex (cbc) in control of such transitional behaviors of various insects. in this study, lesions of the cbc and s ... | 2007 | 17123086 |
| flexible multielectrodes can resolve multiple muscles in an insect appendage. | research into the neuromechanical basis of behavior, either in biomechanics, neuroethology, or neuroscience, is frequently limited by methods of data collection. two of the most pressing needs are for methods with which to (1) record from multiple neurons or muscles simultaneously and (2) perform this recording in intact, behaving animals. in this paper we present the fabrication and testing of flexible multielectrode arrays (fmeas) that move us significantly towards these goals. the fmeas were ... | 2007 | 16899299 |
| dynamics of rapid vertical climbing in cockroaches reveals a template. | rapid, vertically climbing cockroaches produced climbing dynamics similar to geckos, despite differences in attachment mechanism, ;foot or toe' morphology and leg number. given the common pattern in such diverse species, we propose the first template for the dynamics of rapid, legged climbing analogous to the spring-loaded, inverted pendulum used to characterize level running in a diversity of pedestrians. we measured single leg wall reaction forces and center of mass dynamics in death-head cock ... | 2006 | 16857883 |
| passive mechanical properties of legs from running insects. | while the dynamics of running arthropods have been modeled as a spring-mass system, no such structures have been discovered that store and return energy during bouncing. the hindleg of the cockroach blaberus discoidalis is a good candidate for a passive, vertical leg spring because its vertically oriented joint axes of rotation limit the possibility of active movements and contributions of muscle properties. we oscillated passive legs while measuring force to determine the leg's dynamic, mechani ... | 2006 | 16574808 |
| comparison of effects of octopamine and insecticidal essential oils on activity in the nerve cord, foregut, and dorsal unpaired median neurons of cockroaches. | essential oil constituents were tested for their neurophysiological effects in periplaneta americana and blaberus discoidalis. eugenol depressed spontaneous and stimulus-evoked impulses recorded extracellularly in the abdominal nerve cord, with an almost complete block of spikes at 2 x 10(-3) m. geraniol and citral had similar depressive effects but increased spontaneous firing at lower doses (threshold 2.5 x 10(-4) m). similar effects occurred in dorsal unpaired median (dum) neurons, recorded i ... | 2006 | 16406398 |
| kinematics and motor activity during tethered walking and turning in the cockroach, blaberus discoidalis. | when insects turn from walking straight, their legs have to follow different motor patterns. in order to examine such pattern change precisely, we stimulated single antenna of an insect, thereby initiating its turning behavior, tethered over a lightly oiled glass plate. the resulting behavior included asymmetrical movements of prothoracic and mesothoracic legs. the mesothoracic leg on the inside of the turn (in the apparent direction of turning) extended the coxa-trochanter and femur-tibia joint ... | 2005 | 16258746 |
| descending control of body attitude in the cockroach blaberus discoidalis and its role in incline climbing. | unlike intact animals, cockroaches with bilateral circumoesophageal connective lesions have difficulty climbing up smooth inclines. typically, they slipped badly or even fell over backward before traveling more than 1.5 body lengths up the incline. the major problem involves increased slippage of the front and sometimes middle legs. periods of front leg slipping are correlated with excess body elevation that pushes the height of the head to 11 mm above the substrate. intact animals control body ... | 2005 | 15309482 |
| effects of aging on behavior and leg kinematics during locomotion in two species of cockroach. | aging is often associated with locomotor deficits. behavior in aged blaberus discoidalis cockroaches was analyzed during horizontal walking, climbing, righting and inclined walking. adult animals showed a decrease in spontaneous locomotion with increasing age. tarsal abnormalities, termed 'tarsus catch', were often present in aged individuals. in 'tarsus catch', the prothoracic leg catches on the mesothoracic leg during the swing phase. this deficit causes alterations of the gait, but animals ar ... | 2003 | 14610030 |
| feeding effects on gene expression of the hypertrehalosemic hormone in the cockroach, blaberus discoidalis. | feeding effects on hypertrehalosemic hormone (hth) transcript levels in corpora cardiaca (cc) of adult females of the cockroach, blaberus discoidalis were measured using dot blot hybridization. hth transcript levels were nearly doubled in cc from females withheld from food and water for ten days compared to cc from fed females. the increase in hth-mrna was a response to starvation, not dehydration, and reversed within 2 days after exposure to food. hth-mrna was elevated in cc from fed insects th ... | 1998 | 12770433 |
| cuticular proteins from the horseshoe crab, limulus polyphemus. | proteins were purified from the carapace cuticle of a juvenile horseshoe crab, limulus polyphemus, and several of them were characterized by amino acid sequence determination. the proteins are small (7-16 kda) and their isoelectric points range from 6.5 to 9.2. they have high contents of tyrosine, ranging from 13.5 to 35.4%. some of the proteins show sequence similarity to cuticular proteins from other arthropod groups, with the most pronounced similarity to proteins from the cuticle of the spid ... | 2003 | 12628379 |
| dynamic stabilization of rapid hexapedal locomotion. | to stabilize locomotion, animals must generate forces appropriate to overcome the effects of perturbations and to maintain a desired speed or direction of movement. we studied the stabilizing mechanism employed by rapidly running insects by using a novel apparatus to perturb running cockroaches (blaberus discoidalis). the apparatus used chemical propellants to accelerate a small projectile, generating reaction force impulses of less than 10 ms duration. the apparatus was mounted onto the thorax ... | 2002 | 12177146 |
| control of climbing behavior in the cockroach, blaberus discoidalis. ii. motor activities associated with joint movement. | deathhead cockroaches employ characteristic postural strategies for surmounting barriers. these include rotation of middle legs to re-direct leg extension and drive the animal upward. however, during climbing the excursions of the joints that play major roles in leg extension are not significantly altered from those seen during running movements. to determine if the motor activity associated with these actions is also unchanged, we examined the electromyogram activity produced by the slow trocha ... | 2002 | 11935230 |
| control of obstacle climbing in the cockroach, blaberus discoidalis. i. kinematics. | an advantage of legged locomotion is the ability to climb over obstacles. we studied deathhead cockroaches as they climbed over plastic blocks in order to characterize the leg movements associated with climbing. movements were recorded as animals surmounted 5.5-mm or 11-mm obstacles. the smaller obstacles were scaled with little change in running movements. the higher obstacles required altered gaits, leg positions and body posture. the most frequent sequence used was to first tilt the front of ... | 2002 | 11935229 |
| an allometric analysis of oxygen consumption rate and cardiovascular function in the cockroach, blaberus discoidalis. | the interrelationship of metabolic rate and cardiovascular function has been well documented in vertebrates through allometric analyses. however, similar studies are lacking in insects. unlike vertebrates, the cardiovascular system of insects does not play a significant role in oxygen transport. a comparison of the interrelationship in insects and vertebrates might provide insight into the nature of the connection between metabolic rate and the cardiovascular system. oxygen consumption, heart ra ... | 2001 | 11423306 |
| juvenile hormone inhibition of gene expression for cytochrome p4504c1 in adult females of the cockroach, blaberus discoidalis. | the regulation and pattern of gene expression for cytochrome p4504c1 was measured in the fat body of adult females of the cockroach, blaberus discoidalis. the level of cyp4c1-mrna was high at adult emergence but disappeared after 4 days of adult life. in starved females, cyp4c1-mrna levels declined by day 4 but increased steadily thereafter; by 25 days, the levels were nearly twice those observed at eclosion. both the rapid early disappearance of the transcript and the starvation-related increas ... | 1999 | 10451920 |
| many-legged maneuverability: dynamics of turning in hexapods | remarkable similarities in the vertical plane of forward motion exist among diverse legged runners. the effect of differences in posture may be reflected instead in maneuverability occurring in the horizontal plane. the maneuver we selected was turning during rapid running by the cockroach blaberus discoidalis, a sprawled-postured arthropod. executing a turn successfully involves at least two requirements. the animal's mean heading (the direction of the mean velocity vector of the center of mass ... | 1999 | 10333507 |
| hypertrehalosaemic neuropeptides decrease levels of the glycolytic signal fructose 2,6-bisphosphate in cockroach fat body | in cockroach fat body, trehalogenesis and glycolysis compete for glucose phosphates as common substrates. during trehalogenesis, glycolysis is inhibited, although the mechanism responsible for this is not known. incubation of the isolated fat body from the argentine cockroach blaptica dubia with an extract of the corpora cardiaca containing as little as 0.005 gland equivalents ml-1 of incubation medium increased the release of trehalose (anthrone-positive material) from the tissue by more than 1 ... | 1998 | 9600875 |
| energy absorption during running by leg muscles in a cockroach | biologists have traditionally focused on a muscle's ability to generate power. by determining muscle length, strain and activation pattern in the cockroach blaberus discoidalis, we discovered leg extensor muscles that operate as active dampers that only absorb energy during running. data from running animals were compared with measurements of force and power production of isolated muscles studied over a range of stimulus conditions and muscle length changes.we studied the trochanter-femoral exte ... | 1998 | 9487104 |
| the effect of biogenic amines and their analogs on carbohydrate metabolism in the fat body of the cockroach blaberus discoidalis. | several biogenic amines and their analogs were examined for stimulatory effects on glycogen phosphorylase activity and trehalose biosynthesis in fat body of the cockroach, blaberus discoidalis. octopamine and synephrine were the most potent activators of fat body phosphorylase; 10 mum octopamine being nearly as effective as the hypertrehalosemic hormone (hth). epinephrine, norepinephrine, and tyramine produced intermediate effects, whereas dopamine, 5-hydroxytryptamine, and melatonin had no effe ... | 1998 | 9514848 |
| leg kinematics and muscle activity during treadmill running in the cockroach, blaberus discoidalis: ii. fast running. | we have combined kinematic and electromyogram (emg) analysis of running blaberus discoidalis to examine how middle and hind leg kinematics vary with running speed and how the fast depressor coxa (df) and fast extensor tibia (feti) motor neurons affect kinematic parameters. in the range 2.5-10 hz, b. discoidalis increases step frequency by altering the joint velocity and by reducing the time required for the transition from flexion to extension. for both df and feti the timing of recruitment coin ... | 1998 | 9447711 |
| leg kinematics and muscle activity during treadmill running in the cockroach, blaberus discoidalis: i. slow running. | we have combined high-speed video motion analysis of leg movements with electromyogram (emg) recordings from leg muscles in cockroaches running on a treadmill. the mesothoracic (t2) and metathoracic (t3) legs have different kinematics. while in each leg the coxa-femur (cf) joint moves in unison with the femurtibia (ft) joint, the relative joint excursions differ between t2 and t3 legs. in t3 legs, the two joints move through approximately the same excursion. in t2 legs, the ft joint moves throug ... | 1998 | 9447710 |
| three-dimensional kinematics and limb kinetic energy of running cockroaches. | we tested the hypothesis that fast-running hexapeds must generate high levels of kinetic energy to cycle their limbs rapidly compared with bipeds and quadrupeds. we used high-speed video analysis to determine the three-dimensional movements of the limbs and bodies of cockroaches (blaberus discoidalis) running on a motorized treadmill at 21 cm s-1 using an alternating tripod gait. we combined these kinematic data with morphological data to calculate the mechanical energy produced to move the limb ... | 1997 | 9232006 |
| hypertrehalosemic hormone in a cockroach: molecular cloning and expression. | hypertrehalosemic hormone (hth) is a neuropeptide in the adipokinetic hormone/red pigment-concentrating hormone (akh/rpch) family that stimulates the synthesis of trehalose, the main blood sugar of many insects. the preprohth of the cockroach blaberus discoidalis was cloned from the corpora cardiaca (cc), the endocrine source for hth, and the deduced sequence and organization of preprohth were compared with other akh/rpch precursors. preprohth mrna was determined to be approximately 0.5 kb in le ... | 1997 | 9220026 |
| physiological effectors of hyperglycemic neurohormone biosynthesis in an insect. | biosynthesis of hypertrehalosemic hormone (hth) by isolated corpora cardiaca (cc) from blaberus discoidalis cockroaches was measured for the 3-week period following adult ecdysis using an in vitro bioassay based on the incorporation of [3h]tryptophan. synthetic rates for both males and females were highest following the molt and declined with age. rates of hth secretion and levels of stored hth followed a similar pattern. we found no neural or endocrine brain effects or photophase influence on h ... | 1996 | 8912816 |
| calcium-dependent action of hypertrehalosemic hormone on activation of glycogen phosphorylase in cockroach fat body. | signaling mechanisms for blaberus discoidalis hypertrehalosemic hormone (bld-hrth)-dependent glycogen phosphorylase activation were investigated in vitro using fat body of the tropical cockroach, b. discoidalis. brief treatment of fat bodies with bld-hrth in the absence of extracellular ca2+ showed a significant activation of phosphorylase. although extracellular ca2+ was required for a full activation of phosphorylase by bld-hrth, stimulation in the absence of extracellular ca2+ suggested that ... | 1996 | 8647320 |
| free amino acids in the hemolymph of the cockroach, blaberus discoidalis. | the concentrations of free amino acids in the hemolymph of adult males of the cockroach blaberus discoidalis were determined by automated amino acid analysis. eighteen of the twenty standard amino acids as well as two nonstandard amino acids (hydroxyproline and ornithine) were found. aspartic acid and cysteine were not present. proline levels were up to 100-fold higher than those of any other amino acid. total amino acid concentration was comparable to those reported for most other cockroaches. ... | 1996 | 8624903 |
| calcium-dependent signal transduction by the hypertrehalosemic hormone in the cockroach fat body. | the hypertrehalosemic hormones (hrth) are insect peptides that stimulate the fat body to synthesize trehalose. the present research investigated the relative importance of extra- and intracellular ca2+ for hrth signal transduction in the fat body of the cockroach, blaberus discoidalis. although trehalose synthesis could be stimulated significantly by b. discoidalis hrth (bld-hrth) in the absence of ca2+, the presence of ca2+ was necessary to attain a maximum hormonal response. entry of extracell ... | 1995 | 8536949 |
| a study of novel lectins and their involvement in the activation of the prophenoloxidase system in blaberus discoidalis. | endogenous and exogenous lectins have been found to activate the prophenoloxidase (propo) system of the cockroach, blaberus discoidalis, to the same extent as laminarin, a previously known microbial activator of propo. the lectins can also further enhance this laminarin activation of the propo system. non-lectin proteins did not display any activation properties. the time course of propo activation was studied after reconstitution of the reaction system using purified lectins, a trypsin-like enz ... | 1995 | 7646450 |
| in vitro hormonal regulation of glycogen phosphorylase activity in fat body of the tropical cockroach, blaberus discoidalis. | blaberus hypertrehalosemic hormone (bld-hth)-dependent glycogen phosphorylase activation was investigated using in vitro fat bodies from the cockroach, blaberus discoidalis. resting levels of active phosphorylase were decreased by the presence of trehalose and glucose. phosphorylase activation was dose-responsive to bld-hth and increased ca. 3-fold over a range of 0.02 to 2 nm bld-hth. maximum phosphorylase activation required only 5-min exposure to bld-hth; reversion to the inactive state began ... | 1995 | 7628682 |
| maximum single leg force production: cockroaches righting on photoelastic gelatin | integrating studies of mechanics, neural control and isolated muscle function are possible using arthropod legs. to evaluate leg performance, we measured the ground reaction forces generated by individual legs of the six-legged cockroach blaberus discoidalis (3.1 g), during an emergency behavior, righting or over-turning. we used a photoelastic method to measure the forces generated by individual legs simultaneously. a gelatin track placed between crossed polarizing filters was illuminated from ... | 1995 | 9320366 |
| static forces and moments generated in the insect leg: comparison of a three-dimensional musculo-skeletal computer model with experimental measurements | as a first step towards the integration of information on neural control, biomechanics and isolated muscle function, we constructed a three-dimensional musculo-skeletal model of the hind leg of the death-head cockroach blaberus discoidalis. we tested the model by measuring the maximum force generated in vivo by the hind leg of the cockroach, the coxa­femur joint angle and the position of this leg during a behavior, wedging, that was likely to require maximum torque or moment production. the ... | 1995 | 9319155 |
| in vitro bioassay for hypertrehalosemic hormone-dependent trehalose biosynthesis by fat body from adult blaberus discoidalis cockroaches. | an in vitro bioassay suitable for routine use to investigate hypertrehalosemic hormone (hth)-dependent trehalose biosynthesis was developed for the cockroach fat body. blaberus discoidalis fat bodies were isolated and divided so that eight matched pieces from a single tissue could be compared for multiple control and experimental treatments. optimum incubation conditions and the properties of hth-dependent trehalose synthesis were determined. dose-response studies determined an ec50 of 0.044 nm. ... | 1995 | 7711300 |
| intracellular transduction of trehalose synthesis by hypertrehalosemic hormone in the fat body of the tropical cockroach, blaberus discoidalis. | fat body of adult male blaberus discoidalis cockroaches exposed to b. discoidalis hypertrehalosemic hormone (hth) in vitro showed a decline in tissue glycogen as carbohydrate increased in the medium. in vivo hth injections increased hemolymph carbohydrate and fat body glycogen phosphorylase activity > 2-fold compared to controls. in vivo trehalose synthesis was unaffected by agents that enhance intracellular levels of cyclic nucleotides including: dibutyrl camp, dibutyryl cgmp, forskolin (adenyl ... | 1994 | 8205143 |
| hypertrehalosemic hormone effects on transcriptional activity in the fat body of the cockroach, blaberus discoidalis. | gene expression was examined in the fat body of adult male blaberus discoidalis cockroaches in response to the hypertrehalosemic hormone (hth). hth regulates a natural peak of heme synthesis in the fat body at day 4 of adult life. inhibition of transcriptional activity by alpha-amanitin suppressed both the natural increase in heme biosynthesis at day 4, and the increase that was induced in decapitated animals by hth administration. in contrast, the regimen of alpha-amanitin treatments that suppr ... | 1994 | 8025557 |
| metabolism of insect hypertrehalosemic hormone in blaberus discoidalis cockroaches. | | 1993 | 8224399 |
| purification of the pro-phenol oxidase enzyme from haemocytes of the cockroach blaberus discoidalis. | pro-phenol oxidase was purified from the haemocytes of the cockroach blaberus discoidalis by blue sepharose chromatography, hydrophobic-interaction chromatography on a phenyl-superose column and, finally, gel filtration on a superose 6 column. results suggest that the molecule exists as a polymer of identical 76 kda monomeric units. the enzyme is a glycoprotein with pi of 5.2 and can be converted by trypsin into phenol oxidase. | 1993 | 8424776 |
| vasopressin-immunoreactive neurons and neurohemal systems in cockroaches and mantids. | vasopressin-like neuropeptides of insects are of special interest because of their possible function as hormones and neuromodulators. therefore, this study was undertaken by using whole-mount immunofluorescent staining by two antisera that recognize different types of vasopressin-like immunoreactive groups of neurons in the cockroaches periplaneta americana, leucophaea maderae, nauphoeta cinerea, diploptera punctata, and blaberus discoidalis and in the mantids litaneuria minor and tenodera aridi ... | 1992 | 1613132 |
| leg design in hexapedal runners. | many-legged animals, such as crabs and cockroaches, utilize whole-body mechanics similar to that observed for running bipeds and trotting quadrupedal mammals. despite the diversity in morphology, two legs in a quadrupedal mammal, three legs in an insect and four legs in a crab can function in the same way as one leg of a biped during ground contact. to explain how diverse leg designs can result in common whole-body dynamics, we used a miniature force platform to measure the ground reaction force ... | 1991 | 1919412 |
| a novel plasma factor that potentiates prophenoloxidase activation in the immune response of blaberus discoidalis. | | 1990 | 2115467 |
| structure of the hypertrehalosemic neuropeptide of the german cockroach, blattella germanica. | the structure of the hypertrehalosemic neuropeptide of the german cockroach, blattella germanica, was found to be identical to that of the cockroach species, blaberus discoidalis and nauphoeta cinerea (glp-val-asn-phe-ser-pro-gly-trp-gly-thr-nh2). since blattella germanica is not closely related to blaberus discoidalis and nauphoeta cinerea, this supports the hypothesis that in this peptide family evolution of peptide structure may be related to evolution of peptide function. | 1990 | 2080017 |
| structure-activity relationships on hyperglycemia by representatives of the adipokinetic/hyperglycemic hormone family in blaberus discoidalis cockroaches. | several members of the adipokinetic/hyperglycemic neurohormone family from several different invertebrate species have been prepared by solid-phase peptide synthesis and assayed by a modified in vivo hyperglycemic bioassay in blaberus discoidalis cockroaches. the hypertrehalosemic hormone (hrth) is the endogenous hypertrehalosemic factor for b. discoidalis and was the most potent peptide in the assay. the more divergent the sequence of a family member from blaberus hrth, the less potent was the ... | 1990 | 2391403 |
| mechanics of six-legged runners. | six-legged pedestrians, cockroaches, use a running gait during locomotion. the gait was defined by measuring ground reaction forces and mechanical energy fluctuations of the center of mass in blaberus discoidalis (serville) as they travelled over a miniature force platform. these six-legged animals produce horizontal and vertical ground-reaction patterns of force similar to those found in two-, four- and eight-legged runners. lateral forces were less than half the vertical force fluctuations. at ... | 1990 | 2307925 |
| neuroendocrine and juvenile hormone effects on fat body protein synthesis during the reproductive cycle in female blaberus discoidalis cockroaches. | ovarian protein content and fat body protein synthesis were measured during the first gonotrophic cycle in virgin female blaberus discoidalis cockroaches. protein synthesis was measured for in vitro fat bodies from animals treated with combinations of a juvenile hormone analog (jha = methoprene) and corpora cardiaca (cc) extracts. ovarian protein content began to increase on day 5 of adult life and reached its maximum at days 20-22. synthesis of proteins secreted by the in vitro fat body increas ... | 1988 | 3240848 |
| insect hypertrehalosemic hormone: isolation and primary structure from blaberus discoidalis cockroaches. | a new neurohormone was isolated and structurally characterized that increased hemolymph carbohydrate (trehalose) levels in the cockroach, blaberus discoidalis. the hormone was isolated in high yield by a rapid hplc procedure. the sequence, pglu-val-asn-phe-ser-pro-gly-trp-gly-thr-nh2, was suggested from gas-phase edman degradation of a peptide fragment of the natural peptide after deblocking with pyroglutamate aminopeptidase. the structure was confirmed by synthesis of the suggested sequence. th ... | 1986 | 3778476 |
| properties of an in vitro bioassay for hypertrehalosemic hormone of blaberus discoidalis cockroaches. | the ability of the fat body to respond to the hypertrehalosemic action of corpora cardiaca-allata (cc + ca) extracts was measured in vitro with tissue from adult, male blaberus discoidalis cockroaches. only trehalose increased in the hemolymph when gland extracts were injected in vivo; likewise, only trehalose levels responded when fat bodies were exposed to gland extracts in vitro. although fat bodies from 0-day-old animals gave the least response to gland extracts, all animals 5 or more days o ... | 1985 | 3979806 |
| volatile fatty acids of frass of certain omnivorous insects. | the frass of the following omnivorous insects reared on natural and artificial diets was analyzed for volatile fatty acids:blattella germanica, acheta domesticus, blaberus discoidalis. acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids were identified in all frass samples. the possible significance of volatile fatty acids in frass is discussed. | 1985 | 24311098 |
| endocrine regulations of ovarian maturation in the cockroach blaberus discoidalis. | the first gonotrophic cycle of oocyte maturation was defined for virgin blaberus discoidalis cockroaches. a high correlation was found between growth of the basal oocytes and increased ovarian protein content. allatectomy blocked ovarian protein formation, whereas jh-iii administration compensated for the loss of the corpora allata. experiments involving neuro-endocrine surgery and hormone replacement therapy indicated that jh, alone, could stimulate ovarian protein formation; however, the addit ... | 1985 | 2858283 |
| a comparative study of the size-heterogeneous high mannose oligosaccharides of some insect vitellins. | comparative studies of the carbohydrate component from vitellins of the cockroaches blattella germanica, blaberus discoidalis, periplaneta americana and simploce capitata and the locust locusta migratoria have been conducted. chemical, enzymatic and chromatographic analyses show that each vitellin contains variably processed high mannose type oligosaccharides. while all have a common size range they occur as two distinct classes based on the proportion of individual saccharides present. oligosac ... | 1984 | 6509925 |
| isolation of neurosecretory granules containing cytochromogenic hormone activity from the corpora cardiaca of blaberus discoidalis cockroaches. | neurosecretory granules (nsg) were isolated by differential centrifugation from a homogenate of the corpora cardiaca-corpora allata complex of newly emerged, adult, female blaberus discoidalis cockroaches. by centrifuging at 11,000 g, the procedure yielded a final pellet that was enriched in small, membrane-bound vesicles (103 nm mean diameter). this pellet contained 61% of the cytochromogenic activity present in the original homogenate at an 11-fold increase in concentration. a pellet formed at ... | 1983 | 6628975 |
| in vitro metabolism of 14c-dieldrin and some of its metabolites in isolated nerve cords of blaberus discoidalis. | | 1980 | 7357113 |