The response of the follicle cells of Rhodnius prolixus to juvenile hormone and antigonadotropin in vitro

1974 ◽  
Vol 52 (11) ◽  
pp. 1407-1412 ◽  
Author(s):  
K. G. Davey ◽  
E. Huebner
Keyword(s):  
Juvenile Hormone ◽  
Basal Medium ◽  
Rhodnius Prolixus ◽  
Effective Concentration ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
A Value

In a medium consisting of 40% Eagle's basal medium in Schneider's Drosophila medium, large spaces appear between the cells of the follicular epithelium over vitellogenic oocytes of Rhodnius prolixus when juvenile hormone is present. Such spaces are less prominent when juvenile hormone is absent. A method is described by which the size and number of spaces can be assigned a value, on a scale of 0–5, called the index of patency. The index of patency increases with increasing concentration of juvenile hormone from 10−15 μl/ml to 10−4 μl/ml. At higher concentrations, the index of patency decreases. When a source of antigonadotropin is present in the medium, together with juvenile hormone at its maximally effective concentration, the patency index is decreased.

Two actions of juvenile hormone on the follicle cells of Rhodnius prolixus Stål

1975 ◽  
Vol 53 (8) ◽  
pp. 1187-1188 ◽  
Author(s):  
Randa Abu-Hakima ◽  
K. G. Davey
Keyword(s):  
Juvenile Hormone ◽  
Developmental Stages ◽  
Normal Animal ◽  
Rhodnius Prolixus ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Intercellular Spaces

The follicular epithelium of vitellogenic oocytes from allatectomized females of Rhodnius fails to develop large intercellular spaces when exposed to juvenile hormone (JH) in vitro. This suggests that in the normal animal, the follicle cells require JH at two developmental stages. Differentiation of the cells in the presence of JH represents one requirement, and only those cells which have undergone this initial priming are fully competent to exhibit the second response, the development of intercellular spaces.

Patency of the follicular epithelium in Rhodnius prolixus: a re-examination of the hormone response and technique refinement

1980 ◽  
Vol 58 (9) ◽  
pp. 1617-1625 ◽  
Author(s):  
Erwin Huebner ◽  
Hampik S. Injeyan
Keyword(s):  
Regression Analysis ◽  
Juvenile Hormone ◽  
Evans Blue ◽  
Rhodnius Prolixus ◽  
Follicular Epithelium ◽  
Hormone Response ◽  
Penetration Test ◽  
Improved Method ◽  
Dye Penetration

The size of the extracellular spaces revealed by Evans' blue penetration into the follicular epithelium of Rhodnius prolixus increases with the stage of vitellogenesis. This was found to be true of follicles incubated in control media, as well as those whose spaces had been stimulated to expand by incubation in juvenile hormone (JH) or the analogue ZR515. An improved method of estimating hormonal effects in vitro utilizes a regression analysis of patency index relative to follicle length; with control follicles the slope was 0.44, whereas hormone- and analogue-treated follicles yielded slopes of 0.86 and 1.09, respectively. Some pitfalls of the dye penetration test are outlined.

Juvenile hormone increases ouabain-binding capacity of microsomal preparations from vitellogenic follicle cells

1983 ◽  
Vol 61 (7) ◽  
pp. 826-831 ◽  
Author(s):  
T. T. Ilenchuk ◽  
K. G. Davey
Keyword(s):  
Juvenile Hormone ◽  
Binding Capacity ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Curvilinear Relationship ◽  
Scatchard Analysis ◽  
Ouabain Binding ◽  
Binding Characteristics ◽  
Brain Microsomes

A comparison has been made of the effects of juvenile hormone (JH) on the binding characteristics for ouabain of microsomes prepared from brain and from cells of the follicular epithelium surrounding previtellogenic or vitellogenic oocytes in Rhodnius. JH has no effect on the binding of ouabain to brain microsomes and decreases the Kd, but does not alter the Bmax for previtellogenic follicle cells. For vitellogenic follicle cells, Scatchard analysis reveals a curvilinear relationship, which is interpreted as indicating that a new population of JH-sensitive ouabain-binding sites develops as the follicle cell enters vitellogenesis. These results are related to earlier data obtained on the effect of JH on ATPase activity, volume changes in isolated follicle cells, and the development of spaces between the cells of the follicular epithelium.

The binding of juvenile hormone to membranes of follicle cells in the insect Rhodnius prolixus

1985 ◽  
Vol 63 (2) ◽  
pp. 102-106 ◽  
Author(s):  
T. T. Ilenchuk ◽  
K. G. Davey
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Juvenile Hormone ◽  
Binding Sites ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Rhodnius Prolixus ◽  
Follicle Cells ◽  
Scatchard Analysis ◽  
Saturable Binding

3H-labelled insect juvenile hormone, which has previously been shown to stimulate the Na,K-ATPase of membrane preparations of the follicle cells of the ovary of Rhodnius prolixus, exhibits saturable binding to microsomal preparations from the follicle cells of vitellogenic and previtellogenic follicles. No saturable binding is detectable in preparations from brain. Scatchard analysis shows that there is a greater density of binding sites on the membranes from vitellogenic, as opposed to previtellogenic, follicles. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis of solubilized membrane preparations shows that the hormone binds to peptides in two regions of the gel, corresponding to 43 000 and 150 000 daltons. [3H]Ouabain also binds to a peptide in the 150 000 region, as well as to the 100 000 region. Juvenile hormone thus may be binding directly to at least one of the constituent peptides of the Na,K-ATPase complex.

scholarly journals Distribution of yolk polypeptides in the follicle cells during the differentiation of the follicular epithelium in Sarcophaga bullata egg follicles

Development ◽  
1987 ◽  
Vol 101 (1) ◽  
pp. 33-43
Author(s):  
J. Geysen ◽  
J. Cardoen ◽  
A. De Loof
Keyword(s):  
Rna Synthesis ◽  
Follicle Cell ◽  
In Vitro Translation ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Current Pattern ◽  
Sarcophaga Bullata ◽  
Polypeptide Synthesis ◽  
Egg Follicles

In S. bullata, the ovaries contribute to the synthesis of yolk polypeptides. A specific antiserum for yolk polypeptides was used to visualize the presence of yolk polypeptides in the follicle cells during their differentiation. After vitellogenesis has started, all follicle cells contain yolk polypeptides. The squamous follicle cells covering the nurse cells and the border cells lose yolk polypeptides before mid-vitellogenesis, whereas the follicle cells over the oocyte contain yolk polypeptides until after late vitellogenesis. All follicle cells are immunonegative afterwards. In vitro translation of poly(A)+ RNA demonstrated that the presence of yolk polypeptide mRNA correlates well with follicle cell immunopositivity for yolk polypeptides. This suggests that the follicle cells synthesize the ovarian yolk polypeptides. Differences in cellular and nuclear morphology, total and poly(A)+ RNA synthesis and the rate of yolk polypeptide synthesis were shown to be correlated with the presence or absence of yolk polypeptides in the differentiating follicular epithelium. The possible relationship between these different aspects of follicle cell differentiation, follicle cell polyploidy and the extracellular current pattern around follicles are discussed.

Somatic Embryogenesis and In vitro Plant Regeneration in Vigna trilobata (L.) Verd. - A Potential Pasture Legume

1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat
Keyword(s):  
Somatic Embryogenesis ◽  
Growth Regulators ◽  
Somatic Embryos ◽  
Basal Medium ◽  
Long Term Study ◽  
Continuous Application ◽  
First Time ◽  
Pasture Legume

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)

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