The evolution of insect sperm − an unusual character system in a megadiverse group

2016 ◽  
Vol 54 (4) ◽  
pp. 237-256 ◽  
Author(s):  
Marco Gottardo ◽  
Romano Dallai ◽  
David Mercati ◽  
Thomas Hörnschemeyer ◽  
Rolf Georg Beutel
Author(s):  
Sant S. Sekhon

Although there have been numerous studies concerning the morphogenetic changes accompanying the maturation of insect sperm, only a few deal with the sperm differentiation in the dragonflies. In two recent electron microscopic studies Kessel, has comprehensively treated the erlationship of microtubules to the nucleus and mid-piece structures during spermiogenesis in the dragonfly. The purpose of this study is to follow the sequential nuclear and cytoplasmic changes which accompany the differentiation of spermatogonium into a mature sperm during spermatogenesis in the dragonfly (Aeschna sp.).The dragonfly spermatogonia are characterized by large round nuclei. Loosely organized chromatin is usually unevenly distributed within the spermatogonial nuclei. The scant cytoplasm surrounding the nucleus contains mitochondria, the Golgi apparatus, elements of endoplasmic reticulum and numerous ribosomes (Fig. 1).


1977 ◽  
Vol 73 (3) ◽  
pp. 594-600 ◽  
Author(s):  
B Baccetti ◽  
R Dallai ◽  
V Pallini ◽  
F Rosati ◽  
B A Afzelius

Mitochondrial derivatives of insect sperm usually contain a crystalline protein that shows a 45-nm main period, made up of 20-nm subperiods, determined by the coiling of filament bundles. Filaments are 2 nm thick and have a globular appearance. The crystals contain two main polypeptides, 52,000 and 55,000 daltons. These polypeptides are closely related, contain a high percentage of proline, and are insoluble in sodium dodecyl sulfate due to disulfide cross links. We suggest for this class of protein the name crystallomitin.


2021 ◽  
pp. 31-52
Author(s):  
Marina G. Kurgan ◽  

The House of the Dead was repeatedly compared with the first part of Dante’s The Divine Comedy even in F.M. Dostoevsky’s lifetime. However, his contemporaries usually focused on general analogies, while later scholars paid more attention to the narrative features or individual reminiscences. This research studies the main aspects of the artistic structure of the Dante code, constructing the space of Hell in Dostoevsky’s novel. 1. The organization of space. Alexander Petrovich Goryanchikov, the narrator in The House of the Dead, recreates a three-dimensional image that resembles a gradually narrowing funnel: from a bird’s-eye view, where the prison is seen in its entirety, the focus slowly descends, passing to smaller objects, and finally reaching the “three boards”, which limit Goryanchikov’s personal space. The same principle is employed to construct the space of Hell in Dante’s poem. In The House of the Dead, there is another significant indication of the spatial affinity of Dante’s hell and Dostoevsky’s katorga – active imagery associated with cobwebs and spiders. In the centre of the system of images associated with the designated semantic network is the parade- major, the head of the fortress and the owner of the inmate web. 2. The character system as an element constituting the space of Hell. The character system of The House of the Dead follows the compositional principle of Divine Comedy, where sinners are located in different circles in accordance with their main passion. There are three circles in the prison: the first is formal, according to the court decision; the second is informal, internal, formed by crafts and occupations; the third represents Goryanchikov’s perspective as an exponent of human and humane judgment, which distinguishes another person’s moral state. 3. Torment. The House of the Dead demonstrate a hierarchy in describing the tortures, while freedom becomes a fundamental category to embody the most important motif of physical and moral torment connecting Dostoevsky’s novel with Dante’s experience. The bodily torment ceases to be only the torment of the body to become a pain of the soul, comparable to physical torment, so the soul suffers and burns. Hell as a moral topos was the key for Dostoevsky. In The House of the Dead, he chooses the same way as Dante in The Divine Comedy: vivid corporeality conveys an esoteric metaphor of moral suffering and deep inner movements of the soul.


1970 ◽  
Vol 44 (2) ◽  
pp. 243-277 ◽  
Author(s):  
David M. Phillips
Keyword(s):  

2020 ◽  
Vol 32 (2) ◽  
pp. 102-114
Author(s):  
Le Thi Bich Thuy

Sharing the sources of Southeast Asian folklore and folk literature, magical fairy tales of Vietnam and Laos have many similarities in a motif of building orphan characters. Applying structural theory in fairy tales with immutability and changes, the structure of the story is described by a series of events “signs help to make a schematic comparison of the structure of various tales,” (Propp, 1968, p.25) the article studies the magical fairy tale Tam and Cam of Vietnam and the Golden Turtle of Laos to see the similarities and differences in the motif of building orphan characters. The similarities in the motif of building orphan characters such as: story structure, character system, incarnation motif, unique object motif, magical force motif show the common cultural space of the region. However, the difference in the situation of the story and the use of magical forces and elements in the story show the customs, belief characteristics, artistic tastes and cultural identity of each nation.


Author(s):  
E.A. Samarova

I.M. Efimov is a Soviet and Russian abroad writer. His historical works have profound philosophical content. This philosophical content is revealed when we compare his historiosophical treatises about the character and patterns of historical development and historical novels. Philosophical ideas of the writer appear on different poetic levels of the work, and above all - in the plot and character system. Historical novels and historical-philosophical treatises constitute a single historiosophical system and relate to each other as theoretical and empirical material, therefore they cannot be considered one without the other. However, many critics analyze the writer's historical works in isolation from his philosophical concept, which makes such an analysis incomplete and sometimes erroneous. In our study, an attempt was made to trace the connection between the individual characters of the artistic historical works of I. Efimov with his philosophical concept.


2004 ◽  
Vol 45 (2) ◽  
pp. 317-319
Author(s):  
Christopher Gossip

The title of Robert Henke's latest book accurately reflects its innovative contents. The close study of manuscript and printed texts of various kinds—contracts, letters, poems, memorializations, scenarios, treatises, and diaries—sits alongside examination of actors, actresses, the character system, and individual roles to provide the first study devoted to the interaction, indeed cross-fertilization, between the oral and the literary aspects of commedia dell'arte, contrasting yet complementing each other as did binary pairs of arte figures.


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