The effect of acclimation temperature and the removal of peripheral temperature receptors on body temperature preference in the cockroach, Periplaneta americana

1. 1.|Body temperature preferences were compared between cockroaches acclimated to different ambient temperatures and between 25°C acclimated cockroaches and cockroaches deprived of their peripheral temperature receptors.

2. 2.|Acclimation to 35°C resulted in a significantly higher mean body temperature and low body temperature selected compared with 25°C acclimated cockroaches.

3. 3.|Cockroaches deprived of their peripheral temperature receptors showed a significantly higher mean high body temperature selected when compared to normal 25°C acclimated cockroaches.

4. 4.|It is concluded that cockroach temperature regulation is more precise than expected and that central temperature receptors are the primary sensing elements for cockroach thermoregulation.

Protease-mediated prophenoloxidase activation in the haemolymph of American cockroach Periplaneta americana

Prophenoloxidase has been successfully obtained from the haemolymph of the cockroach Periplaneta americana using cane sugar saline solution. The proenzyme was activated by various exogenously added proteases such as chymotrypsin, trypsin, subtilisin and thermolysin. Thermolysin was found to be the greatest activator, followed by chymotrypsin and subtilisin. Chymotrypsin activation showed a lag period when compared with the other proteases tested, indicating that activation by chymotrypsin followed an indirect path, whereas, subtilisin and thermolysin activated the proenzyme directly.Exogenously added protease inhibitor showed inhibition towards protease-mediated prophenoloxidase activation. Benzamidine inhibited chymotrypsin and trypsin activation, whereas soybean trypsin inhibitor inhibited trypsin. In situ inhibitor isolated from the haemocytes of Periplaneta americana inhibited the prophenoloxidase activation and showed evidence for the presence of a built-in inhibition system for the release of the components of the prophenoloxidase activating system of P. americana. Electrophoretic localization of activated phenoloxidase showed two bands, suggesting the dimeric condition of high mol. wt prophenoloxidase.     

美洲大蠊内生菌几丁质酶基因的克隆、表达及其活性研究 *

Objective: To clone the chitinase gene ChiA from the endophytes of Periplaneta americana soluble expression of the protein and to identify its function.Methods:The chitinase gene ChiA was amplified by PCR from the DNA of Serratia marcescens,which was separated from the gut of Periplaneta americana and obtained by subcloning. The expression plasmid ChiA/pET21b was constructed and analyzed by bioinformatics. The plasmid was transformed into E. coli BL21(DE3) and the postive strains were induced by IPTG at 20℃ for 20h. The bioactivity of the protein was determined by small punch test.Results:The cloned sequence was associated with Serratia marcescens ChiA gene of GenBank and their homology was 99%. The sequence encoded a protein containing of 571 amino acids and expressed stably in prokaryotic system.SDS-PAGE/Western blot show that the soluble target protein was obtained. The small punch test suggested that the target protein had the activity of decomposing chitin and was stronger than that of the Serratia marcescens.Conclusion:The chitinase gene ChiA of the Serratia marcescens from the gut of Periplaneta americana was cloned successfully. The soluble chitinase that shows marked bioactivity was attained by prokaryotic expression system, which has provided theoretical basis for its further application.     

Biochemical changes in tissue composition of Periplaneta americana (Linn.) acclimated to high and low temperatures

1. 1.|Cold acclimation apparently favours an increase of water content in fat body, but not in coxal muscle, of cockroaches.

2. 2.|A remarkable enhancement in the accumulation of total protein in fat body characterizes the cold acclimation of cockroaches, particularly adult males (175% increase in protein/DNA ratio). The increase in protein content of coxal muscle during acclimination to 15°C, observed in nymphs (16%) and males (16%) but not in females, is less pronounced than that of fat body.

3. 3.|A diminution (28–32%) in the free amino acid/DNA ratio due to cold acclimation has been recorded in both coxal muscle and fat body of nymphs and females, but not in males.

4. 4.|No qualitative change occurs in the free amino acid spectrum of haemolymph and tissues of this insect during acclimation to 15 and 35°C.

5. 5.|An augmentation (15–30%) of the RNA/DNA ratio occurs in fat body and coxal muscle of nymphs and males but in fat body alone of females following cold acclimation.

6. 6.|The glycogen reserve has been shown to increase by up to 30% in fat body and coxal muscle of cold acclimated cockroaches compared to warm acclimated ones.

Characterization of tactile-sensitive interneurons in the abdominal ganglia of the cockroach,Periplaneta americana

Tactile stimulation of an insect's abdomen evokes various behaviors including grooming and vigorous escape responses. We tested a sample of 37 tactile-sensitive abdominal interneurons for various morphological and physiological characteristics, including their ability to excite thoracic interneurons that are known to integrate wind information conducted by giant interneurons in the classical escape response. The results suggest that abdominal tactile-sensitive interneurons are heterogeneous both in anatomical and physiological properties. In general, these cells are very small interganglionic interneurons that respond to tactile stimulation at more than one abdominal segment. However, the larger population contained virtually all types of cells. Some projected anteriorly, others posteriorly, and still others projected in both directions. For most cells, the soma was on the side opposite to their axons, but in 24% of the cells it was on the same side. Patterns of dendritic arbors also varied among cells. However, tactile sensitivity was in general consistent with the morphological bias noted in dendritic branch patterns. We were able to document the existence of tactile abdominal interneurons that connect directly to thoracic interneurons involved in escape (TI_As). However, instances of demonstrated connectivity were rare. One cell that did show connectivity (AI652) was characterized in detail, and its properties were appropriate for conducting tactile signals in a directional escape system. The dendritic arbors were biased to the side that was ipsilateral to the cell's soma and axon. As a result, this cell's abdominal inputs and thoracic outputs are on the same side. This pattern is appropriate for generating the sensory fields recorded previously in TI_As. Its axon was located in the ventral median tract, which should bring it close to the integrating region of the TI_As. © 1998 John Wiley & Sons, Inc. J Neurobiol 34: 227–241, 1998     

Changes in blood proteins in the cockroach Periplaneta americana after chemosterilization with metepa

Polyacrylamide gel disc electrophoretic studies on the blood proteins of the adult female cockroach Periplaneta americana made sterile by chemical and by surgical means revealed certain differences. While in surgically sterilized animals only the less mobile protein fractions corresponding to soluble oocyte proteins increased in concentration in the blood, in chemosterilized females certain of the more mobile fractions in addition to those corresponding to the less mobile soluble oocyte proteins showed an increase. Various fractions which registered an initial increase in the chemosterilized females showed a tendency to decrease with time, whereas after surgical sterilization they continued to remain higher. However, ovarian degeneration appeared to be irreversible after chemosterilization. Chemosterilization in the female is accompanied by derangement of protein metabolism and inability of the follicle epithelium to take up even available oocyte proteins from the haemolymph.

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Zusammenfassung Mit Hilfe der Polyakrylamid-Gelscheibe unternommene elektrophoretische Untersuchungen der Blutproteinkörper erwachsener weiblicher Küchenschaben (Periplaneta americana), die durch chemische und chirurgische Mittel sterilisiert worden waren, ergaben gewisse Abweichungen. Während bei chirurgisch sterilisierten Tieren nur die weniger beweglichen Proteinkörperanteile, die den Oozytenproteinen entsprechen, in ihrer Konzentration im Blut anstiegen, zeigten bei chemosterilisierten Weibchen sowohl die beweglicheren als auch die weniger beweglichen Anteile eine Zunahme. Verschiedene Anteile, die bei den chemosterilisierten Weibchen anfänglich mit einem Anstieg reagierten, neigten im Laufe der Zeit dazu, wieder abzunehmen, während sie nach chirurgischer Sterilisation stets höher blieben. Jedoch schien nach Chemosterilisation die Eierstockentartung unwiderruflich zu sein. Als Begleiterscheinungen der Chemosterilisation ergeben sich also Störungen im Proteinmetabolismus und die Unfähigkeit des Follikelepithels, selbst die in der Haemolymphe vorhandenen Oozytenproteinkörper aufzunehmen.

     

Potential of Periplaneta fuliginosa densovirus as a biocontrol agent for smoky-brown cockroach, P. fuliginosa

A densovirus, named Periplaneta fuliginosa densovirus (PfDNV), affects smoky-brown cockroach (P. fuliginosa), which is a major peridomestic cockroach in China, southeastern United States, Japan, and Southeast Asia. We reported here that PfDNV could be mass-produced using virus rescue technology. Pathology and ultrastructural studies revealed the presence of enlarged and dense nuclei in hindgut cells of infected smoky-brown cockroach nymphs and adults. Laboratory bioassays of the PfDNV against P. fuliginosa showed that it has the potential to be used as a biocontrol agent. High mortality was recorded in adult smoky-brown cockroaches treated with PfDNV baits at the dosage of 6 × 10⁴ virions per gram against P. fuliginosa in both no-choice tests and two-choice tests (LT₅₀’s were 13.37 and 13.50 days, respectively). PfDNV was also effective in large population chamber tests. LT₅₀ was 17.57 days and mortality achieved was 95.6% in 28 observation days.     

Inositol trisphosphate mediates the action of hypertrehalosemic hormone on fat body of the American cockroach, Periplaneta americana

The rate of synthesis of inositol trisphosphate (InsP₃) in trophocytes derived from disaggregated cockroach (Periplaneta americana) fat body increases following treatment of the cells with hypertrehalosemic hormone I or II (HTH-I, -II) in vitro. Trophocytes preloaded with [³H]inositol display a significant increase in InsP₃ synthesis as early as 15 s after addition of the hormone. When the trophocytes are pre-incubated with LiCl and subsequently incubated with HTH the [³H] content of the InsP₃ fraction is greater than that found with HTH alone. This is taken as evidence that inositol monophosphate phosphatase is part of the mechanism for clearing InsP₃ from the cytosol. In contrast to HTH, octopamine, which is also capable of exerting a hypertrehalosemic effect in the cockroach, does not increase the synthesis of InsP₃. 1-Octadecyl-2-methyl-rac-glycero-3-phosphocholine (ET-18-OCH₃), a potent and selective inhibitor of phosphatidylinositol phospholipase C, blocks the activation of phosphorylase by HTH-I as well as the hypertrehalosemic effect induced by the hormone.     

Food and the spatial distribution of adult female pinworms parasitic in the hindgut of Periplaneta americana L.

Food and the spatial distribution of adult female pinworms parasitic in the hindgut of Periplaneta americana L. International Journal for Parasitology 4: 759–771. The spatial distribution of the two pinworms Hammerschmidtiella diesingi and Leidynema appendiculata in the adult cockroach Periplaneta americana was determined by examination of hind guts fixed by immersion in liquid air. The position of the mouths of the worms reveals that L. appendiculata favours a more anterior position and is more restricted in its distribution than H. diesingi. The position of each species in the colon is unaffected by the presence of the other species or by crowding. Moreover, the two species are segregated in terms of their radial distribution, with the mouth of H, diesingi being restricted to a position near the intima of the colon while that of L. appendiculata favours the lumen. The two nematodes differ in the structure of the stoma and pharynx which reflect a difference in their diet. The food of L. appendiculata consists of relatively large particles while that of H. diesingi is finely patticulate. The ability of these two species to coexist in the same host is explained by their longitudinal and radial distribution and by the different sources of their food.     

Behavioural changes are related to moult regulation in the cockroach, Periplaneta americana

Abstract. Larval holometabolous insects show changes in behaviour (e.g. start of wandering and spinning) in specific periods of the moulting cycle in relation to definite ratios of juvenile hormone and moulting hormone (ecdysone). In hemimetabolous insects no such changes in behaviour are known. It should be investigated whether the cockroach Periplaneta americana shows changes in locomotor activity and in food and water consumption in relation to periods of ecdysone production during the last larval stage. Within a mean duration of the last larval stage of 30 days there were two periods of reduced locomotor activity: on day 9 and between days 13 and 17. From days 12–13 food consumption decreased by c . 40% up to the day 18. Water consumption decreased between days 9 and 18 by about 55%. Peaks of ecdysone production appeared after these changes of behaviour in each case. Therefore in larval Periplaneta ecdysone seems not to trigger these behavioural changes.     

Purification and functional characterization of lectin with phenoloxidase activity from the hemolymph of cockroach,Periplaneta americana

Lectins also identified as hemagglutinins are multivalent proteins and on account of their fine sugar‐binding specificity play an important role in immune system of invertebrates. The present study was carried out on the hemolymph lectin of cockroach, Periplaneta americana with appropriate screening and purification to understand its molecular as well as functional nature. The lectin from the hemolymph was purified using ion‐exchange chromatography. The approximate molecular weight of purified lectin was 340 kDa as determined by FPLC analysis. Rabbit erythrocytes were highly agglutinated with purified lectin from the hemolymph of P. americana. The hemagglutination activity (HA) of lectin was specifically inhibited by fucose. Glycoproteins also inhibited the HA activity of lectin. The amino acid sequences of the purified lectin revealed homology with amino acid sequences of allergen proteins from P. americana. Purified lectin showed the highest phenoloxidase activity against dopamine. The activators such as exogenous proteases and LPS from Escherichia coli and Salmonella minnesota significantly enhanced the PO activity of the purified lectin. Besides, the presence of copper and hemocyanin conserved domain in the purified lectin provided a new facet that insects belonging to the ancient clade such as cockroaches retained some traces of evolutionary resemblance in possessing lectin of ancient origin.     

The influence of penetration, distribution, sorption and decomposition on the poisoning of the cockroach Periplaneta americana treated topically with diazoxon

Microchemical techniques were used to assess the rate of penetration of diazoxon into the American cockroach Periplaneta americana L. by measuring loss from the surface of the cuticle after topical application. By similar methods the proportions of the amount entering which were decomposed, absorbed by the tissues, or circulating in the haemolymph were also estimated. About three-quarters of an LD₉₀ of diazoxon (2.6 g) applied to the metathoracic sternum of adult male cockroaches had penetrated the cuticle 2 hr after treatment. The maximum concentration within the cockroach, reached about 1 hour after treatment, was 2.4 M, but two-fifths of this is sorbed on solids, leaving 1.4 M in the total body fluids. The maximum concentration in the haemolymph occurred 1 1/2 hr. after treatment and ranged from 0.9 to 3.4 M, with a median value of 1.8 M. The close relationship between concentration in haemolymph and in total body fluids suggests that they are in approximate equilibrium.An independent estimate of the concentration of diazoxon in the haemolymph of cockroaches treated with an LD₉₀ of the insecticide, made by means of an electrophysiological technique, agreed well with the values obtained from the chemical assay. The maximum concentrations (0.6–1.0 M) was found 1–2 hr. after treatment, when irreversible damage to the nervous system first occurred.The close agreement between the chemical and biological estimates suggests that diazoxon invades the nerve cord from the haemolymph, and that it acts directly, rather than as a metabolite or by the release of a neuroactive material.

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Zusammenfassung Um die Eindringgeschwindigkeit von Diazoxon in die Amerikanische Küchenschabe Periplaneta americana festzustellen, wurden mikrochemische Verfahren benutzt, indem nach örtlicher Aufbringung das Verschwinden von der Oberfläche der Kutikula gemessen wurde. Mit ähnlichen Methoden wurden auch die Anteile der eingedrungenen Menge abgeschätzt, die abgebaut oder von den Geweben absorbiert wurden oder in der Haemolymphe zirkulieren. Das Eindringen von Diazoxon, das auf dem Sternum des Metathorax erwachsener Küchenschaben-Männchen aufgetragen wurde, ist der vergangenen Zeit proportional, und über 3/4 einer LD₉₀ (2,6 g) ist nach 2 Stunden eingedrungen. Die Menge im Insekt wächst eine Stunde nach der Applikation auf etwa 1/5 der angewendeten Dosis und nimmt nach 2 Stunden auf etwa 1/12 ab. Etwa 2/5 der eingedrungenen Menge wird an ungelöste Stoffe gebunden, und in Anbetracht dessen wurde für die maximal erreichte Konzentration in der gesamten Körperflüssigkeit 1,4 M berechnet, was etwa 1/8 der angewandten Dosis entspricht. Die Zeit-Konzentrations-Kurve des Diazoxons in der Haemolymphe einzelner Küchenschaben, die mit einer LD₉₀ behandelt worden waren, hatte einen ähnlichen Verlauf wie die für das gesamte Diazoxon; die Konzentration erreichte ein Maximum 1 1/2 Stunden nach der Behandlung, wobei es von 0,9 bis 3,4 M mit einem Median wert von 1,8 M schwankte. Die enge Beziehung zwischen der Konzentration in der Haemolymphe und in der gesamten Körperflüssigkeit machte es wahrscheinlich, daß sie annähernd im Gleichgewicht miteinander stehen.Bei der Bespülung von Küchenschaben-Ganglien in vitro mit einer Reihe von Diazoxon-Konzentrationen in Kochsalzlösung unter Beobachtung der Vergiftungssymptome in den Metathorax-Ganglien mit elektrophysiologischen Methoden wurde eine Kurve aufgestellt über die Beziehungen der Diazoxon-Konzentration zu der Zeit, die erforderlich ist, um irreversible Schäden der Nervenfunktion hervorzurufen. Unter Anwendung der gleichen Methoden bei der Beobachtung des Verhaltens der Ganglien in Küchenschaben, die zu bekannter Zeit vorher mit LD₉₀s von Diazoxon örtlich behandelt worden waren, konnte von der Kurve die Diazoxon-Konzentration in der Haemolymphe abgeschätzt werden, wann die Ganglien irreversibel geschädigt wurden. Irreversible Schädigung trat erst 1–2 Stunden nach der Anwendung mit einer LD₉₀ auf, und die Konzentration, die zur Erzeugung des gleichen Vergiftungsstadiums in freigelegten Ganglien in vitro in der gleichen Zeit erforderlich war (0,6–1,0 M), ähnelt eher der mittleren Konzentration (1,8 M), die durch chemische Prüfung in der Haemolymphe ähnlich behandelter Schaben gefunden wurde. Daraus folgt, daß Diazoxon von der Haemolymphe aus in die Ganglien eindringt, und daß es eher direkt wirkt statt als Umwandlungsprodukt oder durch die Entbindung eines neuroaktiven Stoffes.

     

Distribution of serotonergic and dopaminergic nerve fibers in the salivary gland complex of the cockroach Periplaneta americana

Background  

The cockroach salivary gland consists of secretory acini with peripheral ion-transporting cells and central protein-producing cells, an extensive duct system, and a pair of reservoirs. Salivation is controled by serotonergic and dopaminergic innervation. Serotonin stimulates the secretion of a protein-rich saliva, dopamine causes the production of a saliva without proteins. These findings suggest a model in which serotonin acts on the central cells and possibly other cell types, and dopamine acts selectively on the ion-transporting cells. To examine this model, we have analyzed the spatial relationship of dopaminergic and serotonergic nerve fibers to the various cell types.     

Action of two corpus cardiacal peptides on muscles of the hindgut of Periplaneta americana L. (Orthoptera: Blattidae)

1. (1) Two small, basic peptides (Ic and II) which stimulate muscles of the hindgut, but not the heart, have been separated from extracts of the corpora cardiaca by ion exchange chromatography and gel filtration.

2. (2) Results obtained with the 5-HT antagonist mianserin hydrochloride suggest that both peptides stimulate contractions of the hindgut by direct action without mediation by an indoleamine such as 5-HT.

3. (3) Extracellular calcium ions are required for rapid contractions of the hindgut stimulated by peptides Ic and II. However, the tonus response to these peptides does not appear to depend on the same inward transmembrane transport of extracellular Ca²⁺ as rapid contractions.

4. (4) Theophylline (5 mM) potentiated the action of both peptides on hindgut muscle, however, stimulation of hindgut muscle by cardiacal extract did not cause a significant increase in the level of cyclic AMP as compared with controls.

5. (5) These results more clearly define the number, character and possible action of cardiacal peptides stimulating hindgut muscle in P. americana.

     

灭多威对美洲大蠊腹六神经节突触传递的阻断作用

用电生理学方法研究了灭多威对美洲大蠊Periplanetaamerwana腹六神经节(A6节)突触传递的影响。用灭多威溶液浸泡A6节,电刺激尾须神经粗支,用甘露醇间隙法记录兴奋性突触后电位(EPSP)和突触后动作电位。给予弱刺激只记录到EPSP时,灭多威作用初期EPSP幅度增加、时程延长,能诱发突触后动作电位,随后EPSP逐渐减小至消失,冲洗可恢复,突触前反应保持不变。增加电刺激强度记录到突触后动作电位时,灭多威可阻断A6节的突触传递,阻断时间是浓度依赖性的,阻断是可逆的,但冲洗30 min仍保留一定的后作用。对美洲大蠊雄性成虫腹腔注射灭多威测定致死中量(LD₅₀)为(3.56±0.01) μg/g体重。根据灭多威的作用机理对其阻断A6节突触传递的特点以及对虫体的毒杀机制进行了讨论。     

美洲大蠊粪便粗提物的聚集活性

用不同溶剂不同方法提取美洲大蠊Periplaneta americana(L.)粪便,测定美洲大蠊各虫态的诱集活性。结果表明,采用直接浸泡提取方法,丙酮、乙醇、正己烷和二氯甲烷4种粗提物对美洲大蠊各虫态都具有明显的诱集作用,其中乙醇和丙酮粗提物的引诱效果最好,正己烷次之,二氯甲烷最弱。4种溶剂粗提物对美洲大蠊雄成虫和高龄若虫聚集活性最强,对低龄若虫聚集活性最弱。用乙醇溶剂对粪便粗提,3种提取方法均对美洲大蠊有很强的诱集效果,其中索氏抽提诱集效果最弱,直接浸泡和超声波提取效果好,且差异不显著,但直接浸泡提取效果更好。     

Response of thoracic interneurons to tactile stimulation in the cockroach,Periplaneta americana

Receåfindings indicate that cockroaches escape in response to tactile stimulation as well as they do in response to the classic wind puff stimulus. The thoracic interneurons that receive inputs from ventral giant interneurons also respond to tactile stimulation and therefore, represent a potential site of convergence between wind and tactile stimulation as well as other sensory modalities. In this article, we characterize the tactile response of these interneurons, which are referred to as type-A thoracic interneurons (TI_As). In response to tactile stimulation of the body cuticle, TI_As typically respond with a short latency biphasic depolarization which often passes threshold for action potentials. The biphasic response is not typical of responses to wind stimulation nor of tactile stimulation of the antennae. It is also not seen in tactile responses of thoracic interneurons that are not part of the TI_A group. The responses of individual TI_As to stimulation of various body locations were mapped. The left-right directional properties of TI_As are consistent with their responses to wind puffs from various different directions. Cells that respond equally well to wind from the left and right side also respond equally well to tactile stimuli on the left and right side of the animal's body. In contrast, cells that are biased to wind on one side are also biased to tactile stimulation on the same side. In general, tactile responses directed at body cuticle are phasic rather than tonic, occurring both when the tactile stimulator is depressed and released. The response reflects stimulus strength and follows repeated stimulation quite well. However, the first phase of the biphasic response is more robust during high-frequency stimulation than the second phase. TI_As also respond to antennal stimulation. However, here the response characteristics are complicated by the fact that movement of either antenna evokes descending activity in both left and right thoracic connectives. The data suggest that the TI_As make up a multimodal site of sensory convergence that is capable of generating an oriental escape turn in response to any one of several sensory cues. 1994 John Wiley & Sons, Inc.     

Presynaptic inhibition in the cercal-afferent giant-interneurone synapses of the cockroach, Periplaneta americana L.

The occurrence of presynaptic control of synaptic transmission in the cercal-afferent giant-interneurone system of the cockroach was investigated. Reduction in amplitude (up to 50%, lasting about 200–250 ms) of the compound evoked EPSP followed repetitive (300 to 500 Hz) supra-threshold stimulation of cercal nerves XI. A similar but weaker depressive effect was detected on the unitary EPSP resulting from stimulation of an ipsilateral cercal mechanoreceptor.This inhibition is attributed to multisynaptic inhibitory pathways impinging upon presynaptic excitatory neurones. The involvement of chloride ions is suggested by the observation that both picrotoxin and chloride-deficient salines abolished the inhibitory phenomenon. Presynaptic mannitolgap recording from cercal nerve XI revealed a chloride-dependent hyperpolarization in response to repetitive conditioning stimulation. The time course of this response was similar to that of presynaptic inhibition. Bath-application of GABA (20 mM) produced a chloride-dependent hyperpolarization followed by a depolarization of the intraganglionic part of the cerca-afferents. GABA-induced hyperpolarization and electrically-induced presynaptic hyperpolarization were both reversed in low chloride saline (166 mM chloride). It is proposed that presynaptic modulation of acetyl-choline release occurs at the cercal-afferent giant-interneurone synapses. The role played by GABA is duscussed.