scholarly journals IMMUNOLOGICAL STUDIES OF INSECT METAMORPHOSIS

1953 ◽  
Vol 36 (3) ◽  
pp. 389-413 ◽  
Author(s):  
William H. Telfer ◽  
Carroll M. Williams

1. The cell-free blood of the Cecropia silkworm produces a maximum of nine bands of antigen-antibody precipitate when reacted in antiserum-agar tests with antisera prepared by injecting Cecropia extracts into rabbits. The blood antigens producing these bands of precipitate have the properties of proteins in that they are non-dialyzable, labile at 75°C., and salted out by 75 per cent saturated ammonium sulfate. One antigen was identified as a carotenoid protein. 2. Six bands of precipitate were selected for further study. Absorption tests revealed that the blood, at all stages of metamorphosis, is capable of precipitating the antibodies which produce five of these bands. This result indicates that five of the six antigens are present in the blood throughout metamorphosis. The sixth antigen is undetectable in blood from fourth instar larvae, appears in the blood late in the fifth instar, persists during the pupal stage, and disappears again during adult development. 3. When blood samples from various stages of metamorphosis were tested in antiserum-agar tubes, the rates of advance of the six bands of precipitate underwent systematic change in close correlation with the morphological stage of the silkworm's metamorphosis. These changes are interpreted in terms of concentration changes of the corresponding blood antigens. The validity of this interpretation was tested in several ways, with the conclusion that the interpretation was generally acceptable for the system under consideration. 4. All six antigens appear to increase in concentration during the last larval instar and to decrease in concentration during the period of adult development. However, each antigen has its own characteristic pattern of concentration change which differs from those of the other five. In order to explain this diversity, we conclude that the physiological mechanisms which regulate the synthesis and utilization of the blood antigens control each antigen on an individual basis.

2017 ◽  
Vol 69 (2) ◽  
pp. 369-378 ◽  
Author(s):  
Seçkin Soya ◽  
Umut Şahar ◽  
Mehmet Yıkılmaz ◽  
Sabire Karaçalı

Sialic acids mainly occur as components on cell surface glycoproteins and glycolipids. They play a major role in the chemical and biological diversity of glycoconjugates. Although sialic acids exhibit great structural variability in vertebrates, glycoconjugates with sialic acids have also been determined in small amounts in invertebrates. It has been suggested that sialic acids play important roles in the development and function of the nervous system. Despite Bombyx mori being a model organism for the investigation of many physiological processes, sialic acid changes in its nervous system have not been examined during development and aging. Therefore, in this study we aimed to determine sialic acid changes in the nervous system of Bombyx mori during development and aging processes. Liquid chromatography-mass spectrometry (LC-MS) and lectin immunohistochemistry were carried out in order to find variations among different developmental stages. Developmental stages were selected as 3rd instar (the youngest) and 5th larval instar (young), motionless prepupa (the oldest) and 13-day-old pupa (adult development). At all stages, only Neu5Ac was present, however, it dramatically decreased during the developmental and aging stages. On the other hand, an increase was observed in the amount of Neu5Ac during the pupal stage. In immunohistochemistry experiments with Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA) lectins, the obtained staining was consistent with the obtained LC-MS results. These findings indicate that sialic acids are abundant at the younger stages but that they decrease in the insect nervous system during development and aging, similarly as in mammals.


Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2259-2269 ◽  
Author(s):  
Xiaofeng Zhou ◽  
Lynn M. Riddiford

The understanding of the molecular basis of the endocrine control of insect metamorphosis has been hampered by the profound differences in responses of the Lepidoptera and the Diptera to juvenile hormone (JH). In both Manduca and Drosophila, the broad (br) gene is expressed in the epidermis during the formation of the pupa, but not during adult differentiation. Misexpression of BR-Z1 during either a larval or an adult molt of Drosophila suppressed stage-specific cuticle genes and activated pupal cuticle genes, showing that br is a major specifier of the pupal stage. Treatment with a JH mimic at the onset of the adult molt causes br re-expression and the formation of a second pupal cuticle in Manduca, but only in the abdomen of Drosophila. Expression of the BR isoforms during adult development of Drosophila suppressed bristle and hair formation when induced early or redirected cuticle production toward the pupal program when induced late. Expression of BR-Z1 at both of these times mimicked the effect of JH application but, unlike JH, it caused production of a new pupal cuticle on the head and thorax as well as on the abdomen. Consequently, the ‘status quo’ action of JH on the pupal-adult transformation is mediated by the JH-induced re-expression of BR.


2017 ◽  
Vol 114 (5) ◽  
pp. 1057-1062 ◽  
Author(s):  
Takumi Kayukawa ◽  
Akiya Jouraku ◽  
Yuka Ito ◽  
Tetsuro Shinoda

Juvenile hormone (JH) represses precocious metamorphosis of larval to pupal and adult transitions in holometabolous insects. The early JH-inducible geneKrüppel homolog 1(Kr-h1) plays a key role in the repression of metamorphosis as a mediator of JH action. Previous studies demonstrated that Kr-h1 inhibits precocious larval–pupal transition in immature larva via direct transcriptional repression of the pupal specifierBroad-Complex(BR-C). JH was recently reported to repress the adult specifier geneEcdysone-induced protein 93F(E93); however, its mechanism of action remains unclear. Here, we found that JH suppressed ecdysone-inducibleE93expression in the epidermis of the silkwormBombyx moriand in aB. moricell line. Reporter assays in the cell line revealed that the JH-dependent suppression was mediated by Kr-h1. Genome-wide ChIP-seq analysis identified a consensus Kr-h1 binding site (KBS, 14 bp) located in theE93promoter region, and EMSA confirmed that Kr-h1 directly binds to the KBS. Moreover, we identified a C-terminal conserved domain in Kr-h1 essential for the transcriptional repression ofE93. Based on these results, we propose a mechanism in which JH-inducible Kr-h1 directly binds to the KBS site upstream of theE93locus to repress its transcription in a cell-autonomous manner, thereby preventing larva from bypassing the pupal stage and progressing to precocious adult development. These findings help to elucidate the molecular mechanisms regulating the metamorphic genetic network, including the functional significance ofKr-h1,BR-C, andE93in holometabolous insect metamorphosis.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Samy Sayed ◽  
Sayed-Ashraf Elarrnaouty ◽  
Saad AlOtaibi ◽  
Mohamed Salah

This study aimed to estimate the virulence of an indigenous Beauveria bassiana on all developmental stages of two indigenous coccinellids; Coccinella undecimpunctata and Hippodamia variegata through three application methods; direct spray, contact method, and feeding on aphids treated with the fungus (ingestion). Also, indirect effect on all developmental stages resulted from 1st larval instar treated with these application methods. All treatments were done with a concentration of 1 × 105 which was recommended in previous studies for different aphid species with a control of 0.02% Tween 80 (v/v). The mortality of 1st larval instar of both H. variegata and C. undecimpunctata and pupal stage of C. undecimpunctata were significantly increased with spray method only. Also, contact method achieved significantly higher mortality on 1st larval instar of C. undecimpunctata only. Regard to indirect effect, except of mortality of 1st larval instar of both predators and 2nd larval instar of H. variegata, other developmental instars/stages of both predators were not affected by B. bassiana through the three tested application methods in the mortality, duration, survival, cumulative survival male and female longevity, and fecundity. Therefore, both tested predatory coccinellids could be compatible with this indigenous isolate of B. bassiana where, in general, there are no negative effects of the fungus on both predators.


1957 ◽  
Vol s3-98 (41) ◽  
pp. 123-150
Author(s):  
JOAN M. WHITTEN

The fate of the tracheal system is traced from the first larval instar to the adult stage. The basic larval pattern conforms to that shown for other Diptera Cyclorrhapha (Whitten, 1955), and is identical in all three instars. According to previous accounts the adult system directly replaces the larval: the larval system is partly shed, partly histolysed, and the adult system arises from imaginal cell clusters independently of the preceding larval system. In contrast, it is shown here that in the cephalic, thoracic, and anterior abdominal region there is a definite continuity in the tracheal system, from larval, through pupal to the adult stage, whereas in the posterior abdominal region the larval system is histolysed, and the adult system is independent of it in origin. Moreover, in the pupal stage this region is tracheated by tracheae arising from the anterior abdominal region and belonging to a distinct pupal system. Moulting of the tracheal linings is complete at the first and second larval ecdyses, but incomplete at the third larval-pupal and pupal-adult ecdyses. In consequence, in both pupal and adult systems there are tracheae which are secreted around preexisting tracheae, others formed as new ‘branch’ tracheae, and those which have been carried over from the previous instar. In the adult the newly formed tracheae of the posterior abdominal region fall into a fourth category. Most of the adult thoracic air sacs correspond to new ‘branch’ tracheae of other instars. The pre-pupal moult and instar are discussed with reference to the tracheal system and tentative suggestions are made concerning the true nature of the pre-pupal cuticle. There is no pre-pupal tracheal system. Events traced for Drosophila would seem to be general for Cyclorrhapha, both Acalypterae and Calypterae. The separate fates of the anterior and posterior abdom inal systems, in contrast with the straightforward development in Dipterc Nematocera, would appear to mark a distinct step in the evolution of the system in Diptera.


1984 ◽  
Vol 39 (9-10) ◽  
pp. 948-957 ◽  
Author(s):  
Hartmut Kayser ◽  
Ute Krull-Savage

Abstract Incorporation of [14C]5-aminolevulinate and [3H]leucine into cytochrome c, biliprotein and total soluble protein was followed from the last larval instar to the adult stage in Pieris brassicae. The titer of ecdysteroids during the pupal stage was determined with a radioimmunoassay to correlate synthesis of heme products and of protein(s) with adult differentiation. Incorporation of both precursors showed a developmental profile with high synthetic activities in feeding larvae and in pupae after the release of ecdysteroids. Variation of the hormone titer during pupal life differed significantly in males and females. Labeling of cytochrome c by both 14C and 3H was as expected from the variation of its concentration reported in a preceding paper; highest in corporation was around adult emergence. The results demonstrate that i) the accumulation of cytochrome c in the developing adult insect is primarily due to de novo synthesis of both heme and apocytochrome c, performed under coordinate control, and ii) the concentration of 5-aminolevulinate is not rate-limiting in the formation of cytochrome c. Biliverdin IXγ, the major tetrapyrrolic product in this insect, seems to be directly derived from (free) heme and relatively short-lived as deduced from a time-course study. Formation of the bilin, i.e. destruction of heme, increased concomitantly to the initiation of adult differentiation by ecdysteroids in the pupa but later decreased at adult emergence. Synthesis of cytochrome c takes place as a late event during terminal development. Thus, the pathways leading to the two major heme products seem to be differently regulated during development.


1954 ◽  
Vol 45 (2) ◽  
pp. 341-350 ◽  
Author(s):  
Gwyneth C. Williams

Laemophloeus minutus (Ol.) has been reared on six food materials of a type with which the genus, Laemophloeus, is commonly associated in the field. Consideration of the length of egg to adult development, together with the mortality, recorded from each medium indicates that Manitoba wheat and whole-meal flour are equally favourable for the development of the species, followed in order of precedence by Plate maize, English wheat and, finally, National (85 per cent. extraction) and Canadian (70–75 per cent. extraction) flour which proved equally unfavourable.The stage of the life-history at which mortality mainly occurred varied with the diet. The high death-rate on English wheat was caused by the inability of newly hatched larvae to enter grains undamaged in the germ region. Mortality on National and Canadian flour occurred chiefly in the fourth instar.There were indications of cannibalism in both larval and adult stages, at any rate when the diet was unfavourable.The germ of wheat was attacked in preference to any other part of the grain. Maize germ was also consumed but whether it was preferred to the same extent as that of wheat was not established.Pupation was mainly, but not exclusively, intergranular in wheat. Normal cocoons were formed in National and Canadian flours but some larvae pupated in loose webbing or in flour free from webbing and freshly emerged adults were observed in unwebbed National and Canadian flour.


1972 ◽  
Vol 104 (6) ◽  
pp. 797-814 ◽  
Author(s):  
Robert G. Helgesen ◽  
Dean L. Haynes

AbstractThe cereal leaf beetle, Oulema melanopus (L.), has rapidly increased its numbers and range since it was discovered in Michigan in 1962. We have shown in this report that intraspecific density-dependent mortality is the major constraint on survivorship. We have attempted to quantify survival within a generation from the egg stage to the adult.Larval mortality varies among populations. Density-dependent mortality, caused by intraspecific competition, accounts for most of the variation of within-generation survival of the cereal leaf beetle in wheat and oats. Mortality in the first instar on oats and the fourth instar on wheat and oats is a linear function of the logarithm of total egg density. Establishment of the first instar on oats appears to become more difficult as density increases because leaf surface disturbance and interference with larger larva increases. Competition for food accounts for the increase in mortality of the fourth instar in both wheat and oats as density increases. Egg survival, survival of the first instar on wheat and in the second, third, and pupal stage in both crops are constants with respect to density. These constants can be expected to change with respect to other environmental parameters however, e.g. host variety, planting date, rainfall, etc.


1986 ◽  
Vol 76 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Penelope B. Edwards

AbstractThe development of Onitis caffer Boheman in cattle dung was studied in the laboratory. The larvae feed on the dung in which the eggs are laid. Egg to adult development at 25°C was completed in 24·7 weeks by a strain from a winter rainfall (WR) area of South Africa and 29·4 weeks by a strain from a summer rainfall (SR) area, and occurred without diapause. Maximum larval dry weight was achieved mid-way through the third larval instar, after which the larva emptied much of its gut to form a protective faecal shell, in which pupation occurred. At 20°C, 20% of WR larvae developed without diapause and the adults emerged after 33·5 weeks, whereas the remaining 80% of adults emerged after 80·1 weeks. In the SR strain, 70% emerged after 37·1 weeks without having entered diapause, while the remaining 30% emerged after 83·8 weeks. Thus, the period of diapause for both strains was 47 weeks and occurred in the third larval instar. At 15°C, 74% of WR larvae had pupated by 153 weeks, with a mean development time of 121·8 weeks. Zero development temperatures were 10·4°C (WR) and 10·1°C (SR), and day-degree requirements for development without diapause at 20°C were 2251 (WR) and 2571 (SR).


1977 ◽  
Vol 109 (11) ◽  
pp. 1485-1490 ◽  
Author(s):  
E.D.A. Dyer ◽  
P.M. Hall

AbstractThe effect of daily day-degrees C in relation to brood age was investigated to determine its influence on the induction of larval (prepupal) diapause in Dendroctonus rufipennis (Kirby). Daily day-degrees of less than about 9° above the development threshold (6.1°C) induced diapause in most of the broods while diapause was averted by daily day-degrees C of 10 or more above the threshold. Induction of diapause occurred no later than third larval instar; temperature changes during the fourth instar produced no change in aversion or induction of diapause. Laboratory results reveal that field temperatures during larval development determine whether most beetles have a 1- or 2-year life cycle.


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