Effects of intestinal insulin-like peptide on glucose catabolism in mealworm larval fat body in vitro: Dependence on extracellular Ca2+ for its stimulatory action

In vitro hormonally induced variations of glucose catabolism in mealworm fat body tissue were examined by a microradiorespirometric method. An insulin-like peptide (ILP) extracted from the midgut of last larval instar mealworm larvae significantly modified glucose catabolism and was dependent on energy metabolism and on the Ca²⁺ concentration in the culture medium. Using two different labelled substrate molecules, the stimulatory effects of ILP (compared with those of mammalian insulin) on the relative use of the pentose cycle as opposed to the glycolytic-citric acid cycle by the mealworm fat body were measured in vitro. Metabolic variations were evaluated using either [1-¹⁴C]glucose or [6-¹⁴C]glucose as substrates. Time course and dose-response curves of ILP and the hormonally induced variations in total CO₂ and ¹⁴CO₂ kinetics were determined. Modification in the specific radioactivity kinetics of ¹⁴CO₂ derived from [1-¹⁴C] glucose and [6-¹⁴C] glucose molecules under hormonal effects were observed. As demonstrated in in vivo studies, ILP stimulated the relative utilization of the pentose cycle. However, this effect was observed much more rapidly, but for a shorter time, with fat body in vitro. Mammalian insulin produced similar, but not identical effects. Variations in transmembranous Ca²⁺ cellular exchanges, induced by either EGTA, nifedipine, or calcium ionophore ionomycin included in the culture medium, indicated that the stimulatory effects of ILP depends on this cation. © 1993 Wiley-Liss, Inc.     

不同食料植物对东亚飞蝗肠道细菌状况的影响

目的比较在相同的环境条件下不同食料植物对东亚飞蝗肠道细菌状况的影响。方法以墨西哥玉米、野生马唐为食料植物饲喂东亚飞蝗,在其成虫肠道内和粪沙中分离纯化细菌,获得22株菌株,分别对其培养性状、菌体形态、染色反应和生理生化性状进行系统研究。结果上述22个菌株分别属于稀有杆菌属（Rarobact-er）、短状杆菌属（Brachybacterium）、棒杆菌属（Corynebacterium）、棍状菌属（Clavibacter）、葡萄球菌属（Staphylococ-cus）、丙酸杆菌属（Propionibacterium）、埃希菌属（Eschrichia）、气微杆菌属（Aercmicrobium）、沙雷菌属（Serratia）、克雷伯菌属（Klebsiella）、沙门菌属（Salmonella）、志贺菌属（Shigella）、口腔球菌属（Stomatococcus）、短杆菌属（Brevibacteri-um）、地杆菌属（Terrbacter）、微小杆菌属（Exiguobacterium）、皮杆菌属（Dermabacter）、短小杆菌属（Curtobacterium）、纤维单胞菌属（Cellulomonas）、微杆菌属（Microbacterium）、乳杆菌属（Lactobacillus）和凝结芽胞杆菌属（Bacilluscoag-ulans）。结论不同食料植物对东亚飞蝗肠道细菌种类和数量有很大的影响。     

Influence of age on chiasma number in male Locusta migratoria

The influence of age on chiasma formation in Locusta migratoria has been studied both in wild-type and irradiated males. Samples were obtained on the one hand from different individuals and on the other hand from the same individuals at different ages through repeated biopsies. It was observed that mean chiasmata per cell decreased in ageing animals. Chi-squared tests and correlation coefficients showed that the decrease of chiasmata with age is progressive but not continuous. Intermediate values coincide with the first mating. It seems that older individuals tend to transmit their genetic combinations unaltered, increasing the probability of transmitting gene combinations of adaptive value.     

Lom-AG-myotropin: a novel myotropic peptide from the male accessory glands of Locusta migratoria

A myotropic peptide, termed Lom-AG-myotropin, was isolated from extracts of 4400 accessory gland complexes of males of the locust, Locusta migratoria; the following sequence was derived: Gly-Phe-Lys-Asn-Val-Ala-Leu-Ser-Thr-Ala-Arg-Gly-Phe-NH2. This sequence is completely different from all presently known myotropic peptides from Locusta or other insects. The Lom-AG-myotropin is active on the oviduct and hindgut of Locusta migratoria and Leucophaea maderae. The stimulatory activity is, in both insects, 1000 times greater on the oviduct than on the hindgut, suggesting a specificity for the oviduct.     

西藏飞蝗的生物学特性

西藏飞蝗Locusta.migratoria tibetensis Chen在四川甘孜州1年发生1代,某些地方(乡城县)1年发生不完整的2代,即以卵越冬,翌年3月下旬开始孵化出土,4月中、下旬为孵化盛期,1~3龄始盛期为4月中旬~5月中旬,高峰期为5月下旬,7月上旬初始羽化,7月下旬~8月上旬为羽化盛期,8月上旬始见产卵,8月下旬~9月上旬为产卵盛期,第1代成虫较早产下的卵块在条件适宜的情况下可于当年9月上旬孵化出土,但孵化出的蝗蝻不能越冬。该虫卵、全蝻期及全世代的发育起点温度分别为14.2,16.1,14.6℃,有效积温为179.1日.度、360.0日.度、787.8日.度。在18,21,24,27和30℃等5种恒温条件下其平均世代历期214.4,133.3,79.2,66.3和50.7d。     

Crustacean cardioactive peptide is a modulator of oviduct contractions in Locusta migratoria

Crustacean cardioactive peptide (CCAP) stimulates the contractions of locust oviducts. CCAP increased the basal tonus and increased the frequency and amplitude of phasic contractions, as well as the amplitude of neurally-evoked oviduct contractions in a dose-dependent manner. Oviducts from Vth instar larvae and adult locusts aged 10 days or less, were more sensitive to CCAP than oviducts from adult locusts aged 12 days or more. This may be indicative of a differential expression of number or subtypes of CCAP receptors on the oviducts at different ages, and may be related to reproductive functions or to functions of CCAP on the oviducts during ecdysis. The oviducts appear more sensitive to CCAP when compared with previously published reports of CCAP actions on the hindgut. CCAP actions on the amplitude of neurally-evoked contractions of the oviducts are similar to those of proctolin, however, the oviducts are more sensitive to CCAP. No CCAP-like immunoreactive structures were discovered in the nerves innervating the oviducts, or on the oviducts themselves, confirming the previously published suggestion (Dircksen et al., 1991) that CCAP acts as a neurohormone at the oviducts. Cells showing CCAP-like immunoreactivity were discovered in the fat body associated with the oviducts and represent a potential source of CCAP, along with CCAP released from the transverse nerve and perivisceral organs.     

亚洲飞蝗不同发育阶段取食习性的研究

为探明亚洲飞蝗食物选择机制及寄主植物对其生长发育的影响,基于对比称重法、取食频数测定和人工饲喂方式,对亚洲飞蝗不同龄期食量变化、对不同寄主植物喜食程度及主要寄主植物对其生长发育的影响进行研究。结果表明:雌性飞蝗4龄至成虫阶段日取食量分别为0.39±0.02、0.50±0.02、0.75±0.07 g/d。雄性飞蝗4龄至成虫阶段的日取食量分别为0.30±0.06、0.41±0.03、0.71±0.11 g/d。同性别亚洲飞蝗不同发育阶段日取食量间均存在极显著差异。选取小麦、玉米、芦苇、早熟禾、苜蓿、冷蒿等植物,进行取食频数测定。亚洲飞蝗3龄蝗蝻喜食小麦和芦苇,少食苜蓿和早熟禾,偶食玉米,不食冷蒿。4龄蝗蝻嗜食玉米,喜食小麦,少食芦苇,偶食早熟禾,不食苜蓿和冷蒿;5龄蝗蝻喜食小麦,少食芦苇、玉米和早熟禾,偶食苜蓿,不食冷蒿。成虫喜食小麦和玉米,少食芦苇和早熟禾,不食苜蓿和冷蒿。分别以小麦、玉米、芦苇及三者同比例混合物饲养亚洲飞蝗3龄、4龄、5龄蝗蝻后,不同龄期蝗蝻发育历期、交配次数、产卵次数均存在极显著差异。亚洲飞蝗随着年龄段的增长取食量逐渐增加,而亚洲飞蝗同一发育阶段雌性与雄性取食量之间没有显著差异。亚洲飞蝗在每个年龄段对不同的寄主植物具有选择性,主要取食的寄主植物为小麦、玉米和芦苇。与单种饲料饲养相比,以混合饲料饲养的亚洲飞蝗发育历期最短,交配次数最少,产卵次数最多。不同寄主植物对其生长发育有显著的影响。     

东北地区亚洲飞蝗染色体核型分析

采用常规压片法对吉林省亚洲飞蝗Locusta migratoria migratoria(L.)的染色体核型进行分析.研究结果表明:亚洲飞蝗性别决定机制为X0型,染色体数目为2n♂=23,染色体组式4L+4M+3S+X,全部为端部着丝粒染色体,NF=23.染色体中最长(L1)与最短(S11)染色体之比大于4:1,臂比大...     

Isolation and identification of the AKH III precursor-related peptide from Locusta migratoria

We have isolated an 8770Da peptide from extracts of corpora cardiaca of adult male and female Locusta migratoria. The N-terminal amino-acid sequence as partially established by Edman degradation is Ala-Leu-Gly-Ala-Pro-Ala-Ala-Gly-Asp. These nine amino acids correspond to the first nine N-terminal amino acids of the adipokinetic hormone precursor-related peptide gamma-chain (APRP-gamma), a peptide that is predicted from the gene encoding the adipokinetic hormone III precursor. The APRP-gamma chain has a monoisotopic mass of 4387Da and contains two cysteine residues. It is known that both AKH I and AKH II precursors occur as dimers. After processing they give rise to the active hormones and three dimeric (two homodimers and one heterodimer) adipokinetic hormone precursor related peptides (APRPs). Based on the mass of 8770Da and the established N-terminal sequence tag, we conclude that the isolated peptide is a homodimer consisting of two APRP-gamma units, covalently linked to each other by two disulphide bounds. In analogy with the previous identified APRPs (APRP-1, APRP-2, and APRP-3), this APRP will be designated as APRP-4.     

Changes in chemoreceptor sensitivity in relation to dietary selection by adult Locusta migratoria

During somatic growth in adult Locusta migratoria L. there are variations in the responsiveness of chemosensilla on the maxillary palps. Relative changes in chemosensitivity to amino acids and sucrose are consistent with relative changes in protein and carbohydrate ingestion. There is a decline throughout the somatic growth phase in the proportion of sensilla responding to stimulation. In those sensilla which respond, there is a decline in the firing rate to amino acids, while sucrose responsiveness declines to a lesser degree. We suggest that variations in the levels of nutrients in the storage tissues, especially the haemolymph, arising from changes in the demand for protein and carbohydrate for growth, directly or indirectly, influence gustatory sensitivity.

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Résumé Pendant la croissance de L. migratoria L. les réactions aux acides aminés et aux sucres des sensilles chimiques des palpes maxillaires changent. Ces changements relatifs de la sensibilité chimique à ces deux aliments correspondent aux modifications dans l'ingestion de protéines et d'hydrates de carbone par cet insecte. La diminution de la réponse aux acides aminés est liée à la fois au nombre de sensilles qui réagissent et à leur taux de réaction. La sensibilité des sensilles au sucrose varie moins profondément et implique uniquement des modifications du nombre de sensilles réagissant. Nous suggérons que des variations de la teneur en éléments nutritifs de l'haemolymphe, dues à des modifications de la demande en protéines et en glucides nécessaires à la croissance, influent sur la sensibilité gustative.

     

东亚飞蝗血细胞形态学研究

通过Wright's染色和光学显微镜对不同地区东亚飞蝗的血细胞进行了观察,发现东亚飞蝗Locusta migratoria manilensis(Meyen)的血细胞包括原血胞、浆血胞、粒血胞和类绛血胞4种类型.原血胞的细胞核为红色,而其它3种血细胞的细胞核均被Wright's染液染成红色和蓝色2种类型.故认为浆血胞是...     

Flight orientation of swarming Locusta migratoria

ABSTRACT. High-speed films of four swarms of Locusta migratoria in Australia and one swarm in New Guinea were analysed. Measurements were made of the locust's body orientation and flight track in the horizontal relative to wind direction, and of height and speed of flight. In all swarms mean course angle and mean track angle in relation to wind direction were significantly different from zero, although all indicated an upwind direction. No evidence was found for orientation to compass direction or sun. Considerable fluctuations in flight direction were measured in some individuals as they traversed the field of view. A modification of Kennedy's (1951) theory is adopted to explain the angled orientations to wind. It is suggested that this could be the result of an optical orientation mechanism.     

Changes of enzyme patterns in the integument of Locusta migratoria during formation of adult cuticle

The activities of ‘key enzymes’ of the intermediate metabolism (HK, G-6-PDH, GAPDH, GDH, LDH, SDH, ME, GOT, GPT, GluDH) in the integument of the abdomen and of the wings of the migratory locust, Locusta migratoria, were measured 24 hr before, 24 hr after, and 12 days after the last ecdysis. During this time, a significant correlation between these enzyme activity patterns and the formation of the adult cuticle could only be demonstrated in the integument of the wings. GDH, GluDH, and HK, however, were exceptions; their activities increased distinctly during the time after ecdysis.     

飞蝗研究进展

飞蝗作为农业重大害虫,其分布遍及欧洲、亚洲、非洲和澳洲。全世界共有10个亚种,我国有3个亚种。飞蝗不但分布广,而且数量多、发生频率高,危害极为严重。作者在查阅了国内外近20年文献资料的基础上,结合我国蝗害情况,分别从形态、组织、生理、生化、遗传、毒力及分子系统学等方面综述了国内外飞蝗的研究进展,以期对我国飞蝗的基础及应用研究提供参考。     

南大港湿地飞蝗种群分布与芦苇空间格局的关系

利用地统计学方法,在GIS平台下研究南大港湿地东亚飞蝗Locusta migratoria manilensis(Meyen)和芦苇(Phragmites australis)种群的空间格局及两者间的关系。结果表明,研究区域内飞蝗、芦苇种群均具有较强的空间相关性,变异函数曲线都为球状模型,空间自相关范围分别为502m和814m。其次,飞蝗主要集中分布在研究区域内芦苇长势较差(30~70棵.m-2)的东北部和东南部地块,而在长势较好的西部(>120棵.m-2)、南部(70~120棵.m-2)和极差的北部(<30棵.m-2)几乎没有蝗虫的分布,且蝗虫种群数量与芦苇密度存在显著的相关性。     

X-linkage of a vitellogenin gene in Locusta migratoria

Hybridization of a cloned DNA probe to blots of restriction digests of Locusta migratoria genomic DNA showed that a vitellogenin gene is present at one copy per haploid genome in females, and at only one-half that number in males. The genomic region encompassing the 3′-coding end of the gene is polymorphic, as revealed by blots of DNA from individual locusts. DNA from some female locusts yielded two variants in this region, whereas a series of male locusts showed one variant or the other, but never both. The results demonstrate that the vitellogenin gene, which is normally expressed only in females, is X-linked in L. migratoria.     

Dopaminergic control of foregut contractions in Locusta migratoria

Tyrosine hydroxylase-like immunoreactivity is present in cell bodies and processes in the brain and optic lobes of Locusta migratoria, with processes projecting along the frontal connectives to form a neuropile within the frontal ganglion. Immunoreactive cell bodies and processes are also evident in the hypocerebral and ventricular ganglia with processes extending over the foregut. Tyrosine hydroxylase is the rate-limiting enzyme in dopamine biosynthesis, and high-performance liquid chromatography coupled to electrochemical detection was used to confirm the presence of dopamine in the innervation to the foregut. Spontaneous foregut contractions are under the control of the ventricular ganglia and are absent when these ganglia are removed. Dopamine leads to an inhibition of both the amplitude and frequency of phasic contractions of the foregut that are produced when the ventricular ganglia are left attached. Dopamine has direct effects on the foregut muscle in the absence of the ventricular ganglia, inhibiting a proctolin-induced contraction in a dose-dependent manner.     

Effect of azadirachtin A on neuroendocrine activity in Locusta migratoria

Summary The neurosecretory activity of azadirachtin A-treated Locusta migratoria that failed to mature was compared with that of rapidly maturing control females by means of histological techniques. High resolution drymount autoradiography was used to localize [22,23-³H₂]dihydroazadirachtin A in the brain and corpus cardiacum (CC). The neurosecretory system of the locusts treated with this insecticide was accompanied by an unusually high accumulation of paraldehyde fuchsin (PAF)-stainable neurosecretory material (NSM) in the brain fibers and in the storage lobes of the CC. The control females never had such an intense accumulation of NSM. The accumulation of NSM, resulting from its poor release, may influence its synthesis which is controlled by feed-back regulation. [22,23-³H₂]Dihydroazadirachtin A is localized mainly at the peripheral blood-brain barrier and does not penetrate into the brain effectively, whereas it completely covers the CC. It is concluded that azadirachtin A affects the endocrine activity of the brain in an indirect way.     

溴氰菊酯对飞蝗羧酸酯酶基因表达的影响

【目的】研究溴氰菊酯作用下飞蝗羧酸酯酶基因的mRNA表达特性,为溴氰菊酯的代谢解毒及飞蝗Locusta migratoria防治中抗性风险的评估提供基础资料。【方法】本文采用不同剂量溴氰菊酯处理3龄飞蝗,提取总RNA,体外反转录合成cDNA模板,采用Real-time PCR技术分析飞蝗羧酸酯酶基因在溴氰菊酯不同浓度和不同时间处理后的表达模式。【结果】飞蝗经不同浓度溴氰菊酯处理12 h后,LmCesA3和LmCesE1表现为诱导效应;除LmCesA2外,其余羧酸酯酶基因经溴氰菊酯LD30剂量处理后分别在不同的时间点表现为诱导效应。【结论】5个羧酸酯酶基因LmCesA1、LmCesA3、LmCesD1、LmCesE1和LmCesI1可以被溴氰菊酯诱导,表明其可能参与飞蝗对溴氰菊酯的代谢解毒及抗性产生。     

Effects of diet on the chemical composition of migratory locusts (Locusta migratoria)

An experiment was conducted to determine the effects of diet on the chemical composition of migratory locusts (Locusta migratoria L.). Fresh and dry weight and the contents of dry matter, ash, lipid, protein, Ca, K, Mg, Na, P, Cu, Fe, Zn, retinol, lutein, zeaxanthine, cryptoxanthin, carotenes, lycopene and gross energy were determined in penultimate instar and adult locusts, that had been fed three different diets. The locusts received a diet of grass or grass+wheat bran or grass+wheat bran+carrots. Adding wheat bran decreased the protein content and increased fat content (633 vs. 583 and 182 vs. 231 g/kg DM, respectively). Addition of carrots to the diet increased fat content further from 231 to 271 g/kg DM. Mineral concentrations of Ca, K, Mg, and Na, were significantly affected by diet. P, K, Cu, and Fe concentrations were significantly different in penultimate migratory locusts compared with adults. Wheat bran decreased the α-carotene content, which did not change by incorporating carrots in the diet. However, carrots did result in higher β-carotene concentrations. Retinol concentrations were increased by incorporating both wheat bran and carrots in the diet compared with the diet containing only grass. This study shows that the chemical composition of migratory locusts can be manipulated through the diet. As such, it enables nutritionists to adapt the chemical composition of live feeder insects to better meet the nutritional demands of predators.