Reproductive growth in normal, allatectomized, median-neurosecretory-cell-cauterized, and ovariectomized females of Melanoplus sanguinipes

1976 ◽  
Vol 54 (2) ◽  
pp. 162-171 ◽  
Author(s):  
C. Gillott ◽  
R. H. Elliott
Keyword(s):  
Body Weight ◽  
Fat Body ◽  
Neurosecretory Cell ◽  
Initial Period ◽  
Somatic Growth ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Oocyte Growth ◽  
Median Neurosecretory Cells ◽  
Growth Changes

Changes in the weight of the whole insect, fat body, and ovary during successive gonotrophic cycles have been measured. The effects of ovariectomy, cautery of the median neurosecretory cells (mNSC), or removal of the corpora allata (CA) on the development of the fat body and reproductive system have also been observed.After an initial period of somatic growth, changes in body weight are very largely due to growth of the proximal oocytes and to oviposition. Yolk deposition begins when the oocytes are1.0 mm long and occurs most rapidly during the final stages of their development. Vitellogenesis begins in the penultimate oocytes when the proximal oocytes are 3.0–3.5 mm long. Ovariectomy results in a significant increase in the weight of the fat body. Removal of the CA prevents oocyte development beyond the 1-mm stage and production of secretion in the lateral oviducts. Both effects can be reversed by treating operated insects with juvenile hormone. Cautery of the mNSC, provided it is carried out within 3 h of emergence, also inhibits oocyte growth and delays the appearance of secretion in the lateral oviducts.

Changes in the Fat and Protein Content of the African Migratory Locust, Locusta migratoria migratorioides (R. & F.)

1952 ◽  
Vol 43 (1) ◽  
pp. 101-109 ◽  
Author(s):  
S. P. Cheu
Keyword(s):  
Body Weight ◽  
Fat Body ◽  
Locusta Migratoria ◽  
Feeding Activity ◽  
Initial Period ◽  
Adult Life ◽  
Fat Content ◽  
Migratory Locust ◽  
Locusta Migratoria Migratorioides ◽  
Rate Of Increase

The process of build-up of reserve substances in Locusta migratoria migratorioides (R. & F.) is very closely correlated with the feeding activity of the insect. Locusts attain their maximum body weight in the initial period before maturation. In the females there is one minor build-up period after each laying.As measured by the weight of faeces produced, the gregaria female consumes more food than the solitaria during development. It also has a lower rate of increase in body weight, maturation and oviposition.Locusts start to build up fat soon after the final ecdysis. The fat content reaches its maximum in the early part of adult life, and then begins to decline in both sexes of both phases.By far the greater part of the fat reserve thus built up in the gregaria female is used up before oviposition, and only a small amount goes to the making of the first egg-pod. The fat of the subsequent egg-pods (of both phases) is derived from the fat built up each time after a new egg-pod is laid.The solitaria females may mature their eggs at various stages in the development of the fat body. Those which have a longer pre-maturation period have a higher fat content.

Activity of the Corpora Allata during Pupal Diapause in Mimas tiliae (Lepidoptera)

1958 ◽  
Vol s3-99 (46) ◽  
pp. 171-180
Author(s):  
K.C. HIGHNAM
Keyword(s):  
Low Temperature ◽  
Oxygen Uptake ◽  
Fat Body ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Histological Observation ◽  
Corpora Cardiaca ◽  
Pupal Diapause ◽  
The Brain

Histological observation indicates that the corpora allata of Mimas tiliae are secretory during pupal diapause, but become inactive by the end of the low-temperature period which terminates diapause. Removal of the corpora allata, together with the corpora cardiaca, from the diapausing pupa increases the thickness of the hypodermis and decreases the number of fat-body inclusions (compared with operated controls), but does not result in any visible signs of diapause break. The oxygen uptake of the pupa increases by about 60% by the end of the low-temperature period, compared with the diapausing pupa. It is probable that the corpora allata play some part in the maintenance of diapause, possibly by exercising some control over the fat-body metabolism. This role is subservient to that of the neurosecretory cells in the brain, together with their associated corpora cardiaca.

scholarly journals Insulin signalling regulates remating in female Drosophila

2010 ◽  
Vol 278 (1704) ◽  
pp. 424-431 ◽  
Author(s):  
Stuart Wigby ◽  
Cathy Slack ◽  
Sebastian Grönke ◽  
Pedro Martinez ◽  
Federico C. F. Calboli ◽  
...  
Keyword(s):  
Fat Body ◽  
Insulin Signalling ◽  
Underlying Mechanism ◽  
Neurosecretory Cells ◽  
Dominant Negative ◽  
Developmental Defects ◽  
Mating Rate ◽  
Female Remating ◽  
Reduced Body ◽  
Median Neurosecretory Cells

Mating rate is a major determinant of female lifespan and fitness, and is predicted to optimize at an intermediate level, beyond which superfluous matings are costly. In female Drosophila melanogaster , nutrition is a key regulator of mating rate but the underlying mechanism is unknown. The evolutionarily conserved insulin/insulin-like growth factor-like signalling (IIS) pathway is responsive to nutrition, and regulates development, metabolism, stress resistance, fecundity and lifespan. Here we show that inhibition of IIS, by ablation of Drosophila insulin-like peptide (DILP)-producing median neurosecretory cells, knockout of dilp2 , dilp3 or dilp5 genes, expression of a dominant-negative DILP-receptor ( InR ) transgene or knockout of Lnk , results in reduced female remating rates. IIS-mediated regulation of female remating can occur independent of virgin receptivity, developmental defects, reduced body size or fecundity, and the receipt of the female receptivity-inhibiting male sex peptide. Our results provide a likely mechanism by which females match remating rates to the perceived nutritional environment. The findings suggest that longevity-mediating genes could often have pleiotropic effects on remating rate. However, overexpression of the IIS-regulated transcription factor dFOXO in the fat body—which extends lifespan—does not affect remating rate. Thus, long life and reduced remating are not obligatorily coupled.

Morphology and histology of the endocrine glands of Zootermopsis angusticollis Hagen (Isoptera)

1972 ◽  
Vol 50 (12) ◽  
pp. 1537-1547 ◽  
Author(s):  
Cedric Gillott ◽  
Chih-Ming Yin
Keyword(s):  
Cell Types ◽  
Cell Number ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Endocrine Glands ◽  
Histological Changes ◽  
Secretory Cycle ◽  
Zootermopsis Angusticollis ◽  
Primary Reproductives ◽  
Median Neurosecretory Cells

The morphology and histology of the endocrine glands of the various castes of Zootermopsis angmticollis were examined. Six types of median neurosecretory cells are distinguishable by size and stain affinity. No differences in the relative numbers of these cell types among castes can be seen. It is postulated that they may be different forms of the same cell during its synthetic and secretory cycle. Lateral neurosecretory cells can be identified consistently only in mature primary reproductives of both sexes. In the corpora cardiaca two types of cells occur; the fuchsinophilic cells are distributed generally whereas the cells that take up counterstain are restricted to the center of the gland. Intercellular neurosecretory cell product is found throughout the gland. No histological changes associated with the formation of particular castes were observed. The corpora allata (CA) vary in size and histological appearance according to caste but not sex. The CA of reproductives (primary and supplementary) and presoldiers are larger than those of juveniles of the same instar; those of soldiers are about the same size as those of the corresponding juvenile stage. These size increases are due mainly to changes in the ratio cytoplasmic diameter: nuclear diameter of the constituent cells and not to an increase in cell number. The H-shaped molt glands, which, as in other pterygote insects, disappear within a few days of the imaginal molt, are composed of a large prothoracic portion and a smaller cephalic ('ventral gland') portion extending anteriorly and dorsally. Histologically the two components are indistinguishable. Running through the glands are thin strands of muscle.

Changes in the protein concentration and volume of the haemolymph in relation to yolk deposition, ovariectomy, allatectomy, and cautery of the median neurosecretory cells in Melanoplus sanguinipes

1977 ◽  
Vol 55 (1) ◽  
pp. 97-103 ◽  
Author(s):  
R. H. Elliott ◽  
C. Gillott
Keyword(s):  
Protein Synthesis ◽  
Total Protein ◽  
Protein Concentration ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Total Protein Content ◽  
Concentration Increase ◽  
Protein Levels ◽  
Low Protein ◽  
Median Neurosecretory Cells

The protein concentration and volume of the haemolymph may change with no apparent relation to one another in normal, ovariectomized, allatectomized, and median-neurosecretorycell-cauterized (mNSC-cauterized) females. Therefore, protein levels in the haemolymph are more meaningfully expressed in terms of the total protein content. In normal females, fluctuations in the haemolymph volume tend to parallel changes in the protein concentration during the first and subsequent gonotrophic periods. However, significantly less protein accumulates during the latter periods. The suggestion that these fluctuations partly reflect changes in the vitellogenic requirements of the oocytes is supported by the finding that both the volume and protein concentration increase significantly after ovariectomy.Allatectomy or mNSC cautery prevents the normal accumulation of protein in the haemolymph. In allatectomized females, the slight increase in protein concentration is accompanied by a decline in haemolymph volume. Cautery of the mNSC, provided it is performed within 3 h of emergence, results in a low protein concentration but has no effect on the haemolymph volume. The observations are discussed in terms of the corpora allata and mNSC control of haemolymph protein synthesis.

scholarly journals Isolation of material displaying insulin-like immunological biological activity from the brain of the blowfly Calliphora vomitoria

1979 ◽  
Vol 184 (2) ◽  
pp. 221-227 ◽  
Author(s):  
H Duve ◽  
A Thorpe ◽  
N R Lazarus
Keyword(s):  
Biological Activity ◽  
Neurosecretory Cell ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Insulin Receptors ◽  
Neurosecretory Cells ◽  
Bovine Insulin ◽  
Fat Cell ◽  
Median Neurosecretory Cells ◽  
The Brain

An insulin-like material from the brain of the blowfly Calliphora vomitoria was partially purified by acid alcohol extraction, gel filtration and ion-exchange cellulose chromatography. In addition, the RF value on polyacrylamide-gel electrophoresis was determined. The material was characterized by its ability to cross-react with bovine insulin antibody and by displaying diminished immunoreactivity on dilution. It displaced specifically bound 125I-labelled insulin from rat liver plasma membrane insulin receptors and displayed insulin-like biological activity on the isolated rat fat-cell. Within 30 min of injection into Calliphora, made hypertrehalocaemic and hyperglucaemic as a result of median neurosecretory cell removal, it caused the concentrations of both sugars to return to normal. The hypothesis is put forward that the median neurosecretory cells are the source of the material.

THE CORPUS ALLATUM AND OÖCYTE MATURATION IN ADELPHOCORIS LINEOLATUS (GOEZE) (HEMIPTERA: MIRIDAE)

1966 ◽  
Vol 44 (4) ◽  
pp. 719-727 ◽  
Author(s):  
A. B. Ewen
Keyword(s):  
Central Nervous System ◽  
Neurosecretory Cells ◽  
Corpus Allatum ◽  
Corpora Allata ◽  
Oocyte Growth ◽  
Egg Maturation ◽  
Adelphocoris Lineolatus ◽  
Histological Appearance ◽  
The Central Nervous System ◽  
Anatomical Connection

The corpus allatum undergoes marked changes in volume and histological appearance during egg maturation in the adult female of Adelphacoris lineolatus (Goeze). The allatum is very active just before yolk is deposited in the developing oöcytes, but activity declines rapidly at oviposition. This activity in the corpus allatum cannot be correlated with cyclical activity in the cerebral neurosecretory cells. Experiments involving removal of the corpus allatum show that the gland is necessary for oöcyte growth. Implantation of active corpora allata into allatectomized females will not restore egg maturation, and the implanted glands lose their secretory ability. It seems that the corpus allatum in this insect must retain anatomical connection with the central nervous system to produce its hormone.

Histological changes in the ovary in relation to yolk deposition, allatectomy, and destruction of the median neurosecretory cells in Melanoplus sanguinipes

1976 ◽  
Vol 54 (2) ◽  
pp. 185-192 ◽  
Author(s):  
R. H. Elliott ◽  
C. Gillott
Keyword(s):  
Brush Border ◽  
Follicle Cell ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Uptake Mechanism ◽  
Histological Changes ◽  
Pinocytotic Vesicles ◽  
Median Neurosecretory Cells

Histological changes in the ovary during periods of yolk deposition suggest that differentiation of the follicular epithelium and oolemma is an essential prerequisite to the pinocytotic uptake of protein into the oocytes. Before vitellogenesis, intercellular spaces form between adjacent follicle cells, and a brush border appears along the oocyte surface. The presence of protein within these spaces and of elementary yolk spheres along the brush border suggests that protein reaches the oocyte by an intercellular route.Accumulation of yolk does not occur after allatectomy or median neurosecretory cell (mNSC) cautery. Allatectomy inhibits the differentiation of the follicle cells and oolemma. In contrast, after mNSC cautery, differentiation occurs but the pinocytotic vesicles pinched off from the oolemma are empty, indicating that the availability of yolk precursors, not the uptake mechanism, has been affected. In addition, the appearance of secretion in the lateral oviducts is prevented by allatectomy, but merely delayed by mNSC cautery. The findings indicate that the corpora allata, but not the mNSC, are the source of a gonadotropin that regulates follicle-cell differentiation and the development of secretion in the lateral oviducts.

A neuroendocrine relationship between the nematode Hammerschmidtiella diesingi and its insect host, Blatta orientalis

Parasitology ◽  
1970 ◽  
Vol 61 (1) ◽  
pp. 101-110 ◽  
Author(s):  
R. Gordon
Keyword(s):  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Insect Host ◽  
Histological Studies ◽  
Corpora Cardiaca ◽  
Blatta Orientalis ◽  
Adult Nematode ◽  
Median Neurosecretory Cells ◽  
Reproductive Processes ◽  
Terminal Oocyte

Various endocrine operations were performed on the adult female cockroach Blatta orientalis and the adult populations of the nematode Hammerschmidtiella diesingi were recorded 2 or 4 weeks later. Cautery of the median neurosecretory cells (m.n.c.) caused a significant reduction in total numbers of adult nematodes after 2 or 4 weeks; after 2 weeks, removal of the retrocerebral complex (corpora cardiaca plus corpora allata) caused a significant overall reduction in the adult nematode burden and this could not be prevented by reimplanting the corpora allata immediately after the retrocerebral complex had been removed.Anomalies appeared in the data when the sex of the parasite was examined and this may be related to a possible postembryonic mode of sex determination.Both m.n.c. cautery and removal of the retrocerebral complex suppressed host terminal oocyte development and ootheca production, whilst reimplantation of corpora allata into ‘retrocerebralectomized’ cockroaches allowed reproductive processes to continue normally. Hence, the m.n.c. and corpora allata are essential for host egg development.Histological studies showed a profound reduction in fuchsinophilic material in the corpora cardiaca of m.n.c. cauterized cockroaches.Although the m.n.c. may affect the nematode directly or indirectly, a direct effect on the parasite by the corpora allata is unlikely.

HORMONAL CONTROL OF ADULT REPRODUCTIVE DIAPAUSE IN THE EGYPTIAN GRASSHOPPER, ANACRIDIUM AEGYPTIUM, L.

1967 ◽  
Vol 37 (1) ◽  
pp. 63-71 ◽  
Author(s):  
S. GELDIAY
Keyword(s):  
Neurosecretory Cells ◽  
Hormonal Control ◽  
Corpora Allata ◽  
Neurosecretory System ◽  
Reproductive Diapause ◽  
Oocyte Growth ◽  
Adult Diapause ◽  
Normal Individuals

SUMMARY The histology of the cerebral neurosecretory system and the corpora allata of Anacridium aegyptium is similar to that of other locusts, except that the adult diapause of this species introduces differences during oocyte growth. In diapausing adults of Anacridium, the cerebral neurosecretory cells contain large amounts of stainable material; when diapause is broken, the cells contain very much less material as the oocytes develop, but material accumulates once more when the oocytes are fully grown. The corpora allata are small in diapausing females, enlarge considerably during oocyte growth and vitellogenesis in post-diapause insects, and again decrease in size when the oocytes are fully grown. It is inferred from these observations that the neurosecrectory cells and the corpora allata are both inactive during diapause. But the effects upon oocyte growth of destruction of the neurosecretory cells, and of allatectomy, in diapausing females which are subsequently kept under conditions which terminate diapause in normal individuals, strongly suggest that the cerebral neurosecretory system is the primary cause of the inhibition of oocyte growth during adult diapause.

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