scholarly journals Colour pattern regulation after surgery on the wing disks of Precis coenia (Lepidoptera: Nymphalidae)

Development ◽  
1988 ◽  
Vol 102 (2) ◽  
pp. 377-385
Author(s):  
H.F. Nijhout ◽  
L.W. Grunert
Keyword(s):  
Colour Pattern ◽  
Central Field ◽  
Wing Margin ◽  
Cut Edge ◽  
Wing Disk ◽  
Developmental Disturbances ◽  
Pattern Determination ◽  
Precis Coenia ◽  
Pattern Regulation

Partial ablations were done in situ on the imaginal disks of the hindwing in larvae of Precis coenia at ages between 2 and 9 days prior to pupation. While there was no regeneration of the wing lamina, the cut edge developed normal marginal scales and a marginal colour pattern if the ablation was done more than 3–5 days prior to pupation. The response of elements of the marginal colour pattern to partial ablation of the wing disk indicates that the wing margin has an important role in colour pattern determination and appears to act as a sink for a pattern-inducing signal. While the elements of the marginal colour pattern regulate to the shape and position of the new wing margin, the eyespots changed their shape and size but not their position upon partial ablation of the wing disk. When a cut was positioned near one of the dorsal eyespots, the outer rings of the eyespot opened up so that its central field became contiguous with the new margin. The behaviour of the dorsal eyespots of the hindwing in response to ablation of the wing disk, as well as to other developmental disturbances, appears to be the reverse of those on the forewing and ventral hindwing. We conclude that the central field of a dorsal eyespot and the wing margin share similar controlling properties with respect to pattern, and that both appear to act as sinks or as the inverse of the sources of pattern-inducing signal found in the eyespots of the forewing.

Cautery-induced colour patterns in Precis coenia (Lepidoptera: Nymphalidae)

Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 191-203
Author(s):  
H. F. Nijhout
Keyword(s):  
Computer Simulations ◽  
Hind Wing ◽  
Wing Surface ◽  
Colour Pattern ◽  
Physiological Conditions ◽  
Classical Work ◽  
Pattern Determination ◽  
Colour Patterns ◽  
Experimental Findings ◽  
Precis Coenia

Cautery of the dorsal hind wing in the butterfly, Precis coenia, induces the formation of a concentric colour pattern around the site of injury. The induced pattern is identical in pigmentation to the eyespots that normally develop on this wing surface. This response to cautery also occurs, though much less dramatically, on the ventral forewing. In addition to the peculiar response to cautery, the dorsal hindwing of Precis also develops a series of unique pattern aberrations in response to coldshock. These consist of irregular elongation of the anterior eyespot along the proximodistal axis of the wing. In the most dramatic aberrations the eyespot field covers the entire anterior half of the wing surface. An analysis is presented that attempts to reconcile the effects of cautery on the Precis hindwing with the very different morphological effects of cautery on the colour pattern of Ephestia kühniella, described by Kühn & Von Engelhardt. Computer simulations reveal that the finding presented in this paper, as well as the classical work on Ephestia, can both be explained by assuming that the site of cautery becomes a sink for one of the morphogens involved in colour pattern determination. The experimental findings furthermore indicate that minor perturbations of the wing epidermis can evoke the physiological conditions that attend normal eyespot determination. It is shown that this interpretation also helps to explain the unusual pattern modifications following coldshock.

Colour pattern modification by coldshock in Lepidoptera

Development ◽  
1984 ◽  
Vol 81 (1) ◽  
pp. 287-305
Author(s):  
H. Frederik Nijhout
Keyword(s):  
Colour Pattern ◽  
Gradient System ◽  
Experimental Animals ◽  
Vanessa Cardui ◽  
Adult Wing ◽  
Wing Patterns ◽  
Pattern Determination ◽  
Colour Patterns ◽  
Precis Coenia ◽  
Morphological Series

When young pupae of Vanessa cardui, V. virginiensis and Precis coenia (Lepidoptera: Nymphalidae) are exposed to severe coldshock many develop aberrant adult wing patterns. For each species, a synchronous cohort of experimental animals always develops a broad range of aberrant pattern morphologies but these can always be arranged in a single unbranched morphological series. When such phenotypic series are compared, between species and between wing surfaces within a species (each wing surface usually bears a different colour pattern), many parallel modifications and trends become evident. These parallelisms reveal certain homologies of pattern elements and suggest that a common physiology underlies the development of a considerable diversity of normal and aberrant colour patterns. The case is made that the phenotypic series produced may represent either a series of sequential stages in colour pattern determination or, a series of quantitatively different ‘interpretations’ of an established gradient system. Colour pattern morphoclines reveal which patterns are developmentally ‘adjacent’ to one another and may therefore prove useful in elucidating the evolution of patterns.

Pattern determination and pattern regulation in Paramecium tetraurelia

Development ◽  
1983 ◽  
Vol 74 (1) ◽  
pp. 47-68
Author(s):  
Janina Kaczanowska ◽  
Bożena Dubielecka
Keyword(s):  
Paramecium Tetraurelia ◽  
Cortical Areas ◽  
Pattern Determination ◽  
Pattern Regulation

Pattern regulation was investigated in the progeny of laterally fused cells of Paramecium tetraurelia. The immediate progeny of such fused cells (doublets) reveal two sets of cortical organelles arranged roughly symmetrically. Doublets tend to transform gradually into cells with only one set of organelles (singlets). At least two different and mutually exclusive pathways of doublet-to-singlet transformation are reported. In intermediate stages of regulation the cortical areas bearing different cortical landmarks may be brought into an abnormal neighbourhood. Differentiated cortical bands of cortex, bearing organellar landmarks, are faithfully propagated even if they are improperly and asymmetrically located on the cell. The confrontation of such cortical bands may lead to the transient appearance of additional duplicated organelles. It is suggested that pattern regulation in Paramecium during doublet-to-singlet transformation results from at least three factors: the regression of some part of the cortical areas, the interaction of the juxtaposed parts remaining and the slow regulatory shift of positions of the cortical structures.

Proportional regulation of body form and cortical organelle pattern in the ciliate Dileptus

1977 ◽  
Vol 24 (1) ◽  
pp. 11-29
Author(s):  
K. Golinska ◽  
J. Kink
Keyword(s):  
Proximal Portion ◽  
Posterior Region ◽  
Body Form ◽  
Ultrastructural Studies ◽  
Regulatory Processes ◽  
Body Regions ◽  
Dileptus Anser ◽  
The Right ◽  
Pattern Regulation

Morphometric and ultrastructural studies of shape and pattern regulation were performed on Dileptus anser. In this ciliate 2 body regions can be distinguished: proboscis and trunk. When a large portion of the trunk is excised, shape regulation occurs and the proper proboscis/trunk ratio is restored through elongation of the remnant of the trunk and shortening of the proboscis. When there is nothing but proboscis left, the trunk is formed from the proximal portion of proboscis and again the right proportion is restored. Regulation of the ciliary pattern is based mainly on resorption of some ciliary elements. The resorption of somatic ciliature is especially intense within narrowing regions, where otherwise overcrowding of cilia would occur. The resorption of oral ciliature was found to occur within an area located at the apex of the proboscis. Oral structures when damaged by cutting may be repaired in situ. Changes in the microfibrillar system of the cell were found during regulation of shape of the posterior region of the cell, as well as during regulation of size of oral structures. Regulatory processes in Dileptus are compared to those known for other ciliates, and possible differences between the regulation of shape and the regulation of pattern are discussed.

scholarly journals The wing pattern of Moerarchis Durrant, 1914 (Lepidoptera: Tineidae) clarifies transitions between predictive models

2017 ◽  
Vol 4 (3) ◽  
pp. 161002 ◽  
Author(s):  
Sandra R. Schachat
Keyword(s):  
Intraspecific Variation ◽  
Wing Length ◽  
Colour Pattern ◽  
Wing Venation ◽  
Wing Pattern ◽  
Wing Margin ◽  
Pattern Complexity ◽  
Wing Patterns ◽  
Insight Into ◽  
Empirical Insight

The evolution of wing pattern in Lepidoptera is a popular area of inquiry but few studies have examined microlepidoptera, with fewer still focusing on intraspecific variation. The tineid genus Moerarchis Durrant, 1914 includes two species with high intraspecific variation of wing pattern. A subset of the specimens examined here provide, to my knowledge, the first examples of wing patterns that follow both the ‘alternating wing-margin’ and ‘uniform wing-margin’ models in different regions along the costa. These models can also be evaluated along the dorsum of Moerarchis , where a similar transition between the two models can be seen. Fusion of veins is shown not to effect wing pattern, in agreement with previous inferences that the plesiomorphic location of wing veins constrains the development of colour pattern. The significant correlation between wing length and number of wing pattern elements in Moerarchis australasiella shows that wing size can act as a major determinant of wing pattern complexity. Lastly, some M. australasiella specimens have wing patterns that conform entirely to the ‘uniform wing-margin’ model and contain more than six bands, providing new empirical insight into the century-old question of how wing venation constrains wing patterns with seven or more bands.

scholarly journals A simple method to produce fragment seedstock for aquaculture of Pterocladiella capillacea (Gelidiales, Rhodophyta)

ALGAE ◽  
2021 ◽  
Vol 36 (4) ◽  
pp. 327-332
Author(s):  
Chang Geun Choi Choi ◽  
Ju Il Lee Lee ◽  
Il Ki Hwang ◽  
Sung Min Boo
Keyword(s):  
Slow Growth ◽  
High Capacity ◽  
Laboratory Culture ◽  
Raw Material ◽  
High Quality ◽  
Simple Method ◽  
Short Supply ◽  
Cut Edge ◽  
Pterocladiella Capillacea

Raw material of gelidioid red algae yielding high-quality agar has been in short supply due to overharvesting, but in situ farming of gelidioids has not been practical due to their slow growth. To produce vegetative seedstock of a cosmopolitan species, Pterocladiella capillacea, we investigated the number and length of regenerated branches arising from sectioned fragments during 3 weeks of laboratory culture at 10, 15, 20, and 25°C. All sectioned fragments formed axis-like branches mostly from the upper cut edge and stolon-like branches mostly from the lower cut edge, showing a high capacity of regeneration and intrinsic bipolarity. At 20°C, the number of regenerated branches increased to 2.74 ± 1.29 on the upper cut edge and 4.26 ± 2.66 on the lower cut edge. Our study reveals that the use of fragments bearing regenerated branches as seedstock can be a simple method to initiate fast propagation for mass cultivation in the sea or outdoor tank.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

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