scholarly journals The specification of metameric order in the insect Callosobruchus maculatus Fabr. (Coleoptera)

Development ◽  
1979 ◽  
Vol 51 (1) ◽  
pp. 1-26
Author(s):  
Jitse M. van der Meer
Keyword(s):  
Cell Differentiation ◽  
Callosobruchus Maculatus ◽  
Dorsal Closure ◽  
Stages Of Development ◽  
Morphogenetic Process ◽  
Different Types ◽  
Constriction Region

Eggs of the pea-beetle Callosobruchus were divided into two at different stages of development. Both fragments were allowed to develop into partial larvae. The segment patterns of normal and partial larvae are described using cuticular markers of cell differentiation. To study the contribution of cytological damage to the segment gap phenomenon three different types of constriction were performed: complete and incomplete permanent constriction and complete temporary constriction. Changes in the structure of the egg can produce absence of segments resulting from two different effects. First, partial absence of segments results from a decreased egg circumference in the constriction region and involves the disturbance of a morphogenetic process (dorsal closure). Secondly, cytological damage can result in a gap between two arrays of segments. The loss of segments in the gap occurred in two different ways. In a spatial segment gap the two arrays of segments were physically discontinuous, whereas in a non-spatial gap the segments bordering the gap were juxtaposed in a physically continuous cuticle. The extent to which the gap phenomenon can be attributed to cytological damage is discussed. We also discuss, on the basis of certain dorsal defects, a possible stepwise specification of the dorsal transverse cuticular pattern.

scholarly journals Two consecutive microtubule-based epithelial seaming events mediate dorsal closure in the scuttle fly Megaselia abdita

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Juan Jose Fraire-Zamora ◽  
Johannes Jaeger ◽  
Jérôme Solon
Keyword(s):  
Drosophila Melanogaster ◽  
Signaling Pathways ◽  
Genetic Regulation ◽  
Dorsal Closure ◽  
Evolutionary Transition ◽  
Morphogenetic Process ◽  
Signaling Regulation ◽  
Tissue System ◽  
Megaselia Abdita

Evolution of morphogenesis is generally associated with changes in genetic regulation. Here, we report evidence indicating that dorsal closure, a conserved morphogenetic process in dipterans, evolved as the consequence of rearrangements in epithelial organization rather than signaling regulation. In Drosophila melanogaster, dorsal closure consists of a two-tissue system where the contraction of extraembryonic amnioserosa and a JNK/Dpp-dependent epidermal actomyosin cable result in microtubule-dependent seaming of the epidermis. We find that dorsal closure in Megaselia abdita, a three-tissue system comprising serosa, amnion and epidermis, differs in morphogenetic rearrangements despite conservation of JNK/Dpp signaling. In addition to an actomyosin cable, M. abdita dorsal closure is driven by the rupture and contraction of the serosa and the consecutive microtubule-dependent seaming of amnion and epidermis. Our study indicates that the evolutionary transition to a reduced system of dorsal closure involves simplification of the seaming process without changing the signaling pathways of closure progression.

scholarly journals Drosophila R8 photoreceptor cell subtype specification requires Notch and hibris

2018 ◽  
Author(s):  
Hong Tan ◽  
Ruth E. Fulton ◽  
Wen-Hai Chou ◽  
Denise A. Birkholz ◽  
Meridee P. Mannino ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Differentiation ◽  
Photoreceptor Cell ◽  
Compound Eye ◽  
Visual Pigments ◽  
Exact Nature ◽  
Diverse Range ◽  
Developmental Program ◽  
Color Sensitivity ◽  
Different Types

AbstractCell differentiation and cell fate determination in sensory systems are essential for stimulus discrimination and coding of environmental stimuli. Color vision is based on the differential color sensitivity of retinal photoreceptors, however the developmental programs that control photoreceptor cell differentiation and specify color sensitivity are poorly understood. In Drosophila melanogaster, there is evidence that the color sensitivity of different photoreceptors in the compound eye is regulated by inductive signals between cells, but the exact nature of these signals and how they are propagated remains unknown. We conducted a genetic screen to identify additional regulators of this process and identified a novel mutation in the hibris gene. hibris encodes an irre cell recognition module protein (IRM). These immunoglobulin super family cell adhesion molecules include human neph and nephrin (NPHS1). hibris is expressed dynamically in the developing Drosophila melanogaster eye and loss-of-function mutations give rise to a diverse range of mutant phenotypes including disruption of the specification of R8 photoreceptors cell diversity. The specification of blue or green sensitivity in R8 cells is also dependent upon Notch signaling. We demonstrate that hibris is required within the retina, non-cell autonomously for these effects, suggesting an additional layer of complexity in the signaling process that produces paired expression of opsin genes in adjacent R7 and R8 photoreceptor cells.Author SummaryAs humans, our ability to distinguish different colors is dependent upon the presence of three different types of cone cell neurons in the retina of the eye. The cone cells express blue, green or red absorbing visual pigments that detect and discriminate between these colors. The principle of color discrimination by neurons “tuned” to different colors is an evolutionarily conserved specialization that occurs in many different animals. This specialization requires 1) visual pigments that detect different colors and 2) a developmental program that regulates the expression of these pigments in different types of cells. In this study we discovered that the fruit fly (Drosophila melanogaster) gene hibris is required for the developmental program that produces blue sensitive neurons in the fly retina. When we over-expressed hibris throughout the developing retina, extra blue sensitive cells were produced. These results demonstrate that if there is not enough hibris, too few blue sensitive cells form, but if there is too much hibris, too many blue sensitive cells form. Finally, we discovered that the hibris gene does not act in color sensitive neurons of the retina themselves. This surprising discovery suggests that hibris may influence development of the retina in a completely new and different way.

Craniofacial development: a summing up

Development ◽  
1988 ◽  
Vol 103 (Supplement) ◽  
pp. 245-249 ◽  
Author(s):  
L. Wolpert
Keyword(s):  
Cell Differentiation ◽  
Cell Biology ◽  
Spatial Organization ◽  
Tissue Level ◽  
Strict Sense ◽  
Cell Sheets ◽  
Different Types ◽  
Differentiation Pattern ◽  
Craniofacial Biology ◽  
Molecular Cell Biology

It is convenient to distinguish between three related problems in development: cell differentiation; pattern formation, which is about spatial organization; and morphogenesis in the strict sense, which is about change in form, particularly of cell sheets, but includes cell migration (Wolpert, 1981; Wolpert & Stein, 1984). All these need to be linked to gene action. If one looks forward over the next five to ten years then the future of craniofacial biology lies in molecular cell biology. This is not to say that all the problems at the tissue level have been solved, quite the contrary, but rather that the emphasis must now be at the cell and molecular level. One can illustrate some of the problems of cell differentiation – and the approaches involved – with the differentiation of the cells of the haemopoietic system. Here we have a stem cell that can give rise to all the different types of blood cell.

scholarly journals An epigenetic landscape governs early fate decision in cellular aging

2019 ◽  
Author(s):  
Yang Li ◽  
Yanfei Jiang ◽  
Julie Paxman ◽  
Richard O’Laughlin ◽  
Lorraine Pillus ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Cell Fate ◽  
Quantitative Model ◽  
Cellular Aging ◽  
Multiple Equilibrium ◽  
Epigenetic Landscape ◽  
Genetically Engineer ◽  
Different Types ◽  
Extended Lifespan ◽  
Fate Decision

AbstractChromatin instability and mitochondrial decline are conserved processes that contribute to cellular aging. Although both processes have been explored individually in the context of their distinct signaling pathways, the mechanism that determines which cell fate arises in isogenic cells is unknown. Here, we show that interactions between the chromatin silencing and mitochondrial pathways lead to an epigenetic landscape with multiple equilibrium states that represent different types of terminal cellular states. Interestingly, the structure of the landscape drives single-cell differentiation towards one of these states during aging, whereby the fate is determined quite early and is insensitive to intracellular noise. Guided by a quantitative model of the aging landscape, we genetically engineer a new “long-lived” equilibrium state that is characterized by a dramatically extended lifespan.

scholarly journals The Less Known Cyclins—Uncovered

2021 ◽  
Vol 11 (5) ◽  
pp. 2320
Author(s):  
Agnieszka Żuryń ◽  
Aleksandra Opacka ◽  
Adrian Krajewski ◽  
Wioletta Zielińska ◽  
Alina Grzanka
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Cell Differentiation ◽  
Cancer Cells ◽  
Present Report ◽  
Life Stage ◽  
Cyclin Dependent Kinases ◽  
Current State ◽  
Different Types ◽  
A Cell

Cyclins belong to a group of proteins that are cyclically produced and destructed in a cell. Cyclins are a family of proteins that are a key component of the cell cycle regulating system, which level of expression depends on the phase of the cycle. Cyclins regulate the activity of cyclin-dependent kinases (Cdk), thanks to which they influence the length of individual phases of the cell cycle and also determine whether the cell can enter the next life stage. Proper expression of cyclins plays an important role in processes such as proliferation, transcription, DNA repair and cell differentiation. However, dysregulation of their expression is one of the most important disorders leading to the development of different types of cancer, which suggests that cyclins can be defined as a prognostic marker. Currently, we may distinguish >10 members of the cyclins family participating in the division of human cells. The group of less known cyclins includes C, F, G, H, I, J, K, L, M, O, T and Y cyclins. The present report demonstrates the current state of knowledge considering less known cyclins and their role in normal and cancer cells.

scholarly journals Cellular Interactions in Cell Differentiation

Development ◽  
1953 ◽  
Vol 1 (3) ◽  
pp. 283-285
Author(s):  
Rodolfo Amprino
Keyword(s):  
Cell Differentiation ◽  
Normal Development ◽  
Chick Embryos ◽  
Cellular Interactions ◽  
Stages Of Development ◽  
Anatomical Region ◽  
Larval Amphibians ◽  
Heterogeneous Tissues ◽  
Different Tissues

It is of some interest, in connexion with the problem of cellular interactions, to view the affinities between different tissues in various stages of development. The problem has been extensively investigated by Holtfreter in the early stages of the amphibian egg. Professor P. Weiss has briefly reported on the stimulating observations made by Chiakulas (1952) on grafts of epithelia from various sources to the skin of larval amphibians. I have performed experiments which bear some analogies to the last-mentioned ones by confronting side by side in situ layers of heterogeneous tissues, which in normal development form distinct constituents of one anatomical region, namely the eye region. Pieces of tissues of various extent were mechanically removed from the eye-forming region of chick embryos of from 2 to 30 somites, and more or less wide gaps created.

scholarly journals A and B mode ultrasonography in preoperative evaluation of lens and posterior segment of dogs eyes with cataract

2010 ◽  
Vol 30 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Bianca C. Martins ◽  
Emilio F. Rodrigues Jr ◽  
Ana L.G. Souza ◽  
Denise E. Almeida ◽  
Fábio L.C. Brito ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Clinical Examination ◽  
Preoperative Evaluation ◽  
Posterior Segment ◽  
Nuclear Cataract ◽  
Stages Of Development ◽  
Lens Subluxation ◽  
Cortical Cataract ◽  
Cataractous Lens ◽  
Different Types

Ultrasonography of the lens and posterior segment is an indispensable step in the preoperative evaluation of dogs with cataracts, since ophthalmoscopy is not feasible when there is opacification of the lens. This study evaluated the echographic conditions of cataractous lens and fundus of the eye in dogs affected by cataracts. The study was conducted in 30 dogs (56 eyes), 10 males and 20 females, with different types of cataracts at different stages of development. Echography in A and B modes, simultaneously, was carried out for the examination of the lens and posterior segment. The examinations revealed anterior cortical, posterior cortical and nuclear cataract in 12 eyes (21.4%), anterior cortical, posterior cortical, nuclear and posterior capsular in 23 eyes (41%), anterior cortical, posterior cortical and posterior capsular cataract in one eye (1.7%), anterior cortical and nuclear cataract in one eye (1.7%), anterior cortical, nuclear and posterior capsular cataract in five eyes (8.9%), and anterior cortical cataract in seven eyes (12.5%). Abnormal ultrasonographic alterations were observed in the posterior segment in 26 eyes evaluated (46.4%). Vitreal degeneration was detected in 12 eyes (21.4%), images of vitreal exudate or hemorrhage in seven eyes (12.5%), persistence of hyaloid artery in four eyes (7.1%) and lens subluxation in three eyes (5.3%). The results obtained reiterate the importance of ultrasonography in canine patients presented for cataract surgery given that alterations of the posterior segment are difficult to identify in a clinical examination when the lens is opacified.

scholarly journals ABOUT THE DECOR OF THE HARPOON HEADS OF THE OLD BERING SEA CULTURE

2019 ◽  
Author(s):  
Е.С. Сухорукова
Keyword(s):  
Bering Sea ◽  
Symbolic Meaning ◽  
Technological Parameters ◽  
Stages Of Development ◽  
Cultural Traditions ◽  
Different Types

В жизни древних эскимосов гарпун, главное охотничье орудие, был также важным ритуально-магическим предметом, в котором каждая деталь имела конкретное символическое значение и украшалась определенным образом. Статья посвящена эволюции декора наконечников гарпунов древнеберингоморской культуры. На разных этапах развития древнеберингоморья использовались различные варианты гарпуна, имеющие как конструктивные, так и декорационные особенности. Общее художественное оформление орудия соответствовало стилистике того или иного периода, иконография головок гарпунного древка и крылатых предметов с изменением их технологических параметров менялась, декор же наконечников, несмотря на многообразие конструктивных вариаций, оставался достаточно консервативным. Две канонические схемы художественного оформления для типов с концевым копьецом и для типов с боковыми вкладышами сохраняли актуальность на протяжении всего существования древнеберингоморской культуры и получили дальнейшее развитие в декоре наконечников ранней пунукской и бирниркской культурных традиций. In the life of the ancient Eskimos, the harpoon, the main hunting weapon, was also an important ritual and magical object in which every detail had a specific symbolic meaning and was decorated in a certain way. The article is devoted to the evolution of the decor of the harpoon heads of the Old Bering Sea (OBS) culture. At different stages of development of OBS culture different versions of the harpoon were used, having both structural and decorative features. The general artistic design of the hunting weapon corresponded to the style of a particular period, the iconography of the harpoon shaft and winged objects with the developing of their technological parameters were changing, while the decor of the harpoon heads, despite the variety of design variations, remained quite conservative. Two canonical schemes of artistic design for different types of harpoon heads remained relevant throughout the existence of the OBS culture and were further developed in the decoration of the harpoon heads of the early Punuk and Birnirk cultural traditions.

scholarly journals Efeito de Diferentes Tipos de Injúrias Causadas nos Estádios Iniciais de Desenvolvimento da Soja

2016 ◽  
Vol 9 (3) ◽  
pp. 193-196
Author(s):  
Eires Tosta Fernandes ◽  
Crébio José Ávila
Keyword(s):  
Glycine Max ◽  
Plant Height ◽  
Aerial Part ◽  
Insect Pests ◽  
Fresh Weight ◽  
Stages Of Development ◽  
Development Stages ◽  
Early Stages ◽  
Different Types ◽  
Glycine Max L

A soja, Glycine max (L.), é uma cultura que pode ser prejudicada por insetos-praga durante todo o ciclo fenológico, principalmente nos estádios iniciais  desta cultura. O objetivo deste trabalho foi avaliar a resposta da cultura da soja a diferentes tipos de injúrias artificiais causadas nos seus estádios iniciais de desenvolvimento. O experimento foi conduzido na área experimental da Embrapa Agropecuária Oeste, utilizando-se as cultivares FTS Campo Mourão e BRS Potência, as quais foram submetidas aos seguintes tipos de injúrias iniciais: 1) Remoção de um cotilédone; 2) Remoção de dois cotilédones; 3) Remoção de dois cotilédones e uma folha unifoliolada; 4) Remoção de dois cotilédones e duas folhas unifolioladas; 5) Remoção de uma folha unifoliada; 6) Remoção de duas folhas unifolioladas; 7) Corte abaixo das folhas unifolioladas; 8) Corte do broto trifoliado; 9) Testemunha (sem injúria). A altura das plantas, o número de vagens/planta e o peso verde da parte aérea da cultivar FTS Campo Mourão foram menores quando comparado com os valores desses parâmetros obtidos na cultivar BRS Potência. Foi também constatado redução na altura das plantas de soja nos tratamentos 3, 4, 6 e 7 quando comparado à testemunha. O rendimento de grãos (Kg ha-1) foi semelhante nas duas cultivares e não foi influenciado pelos diferentes tipos de injúrias causados nas plantas. Já o peso de 100 sementes (g) foi maior na cultivar FTS Campo Mourão quando comparado a cultivar BRS Potência. Independente dos tipos de injúrias que são causadas, as plantas apresentam capacidade de recuperação ao dano.Effect of Different Types of Injury Caused During the Early Soybean Development Stages Abstract. The soybean, Glycine max (L.), is a crop that can be damaged by insect pests throughout its phonological cycle, particularly in the early stages of development of this culture. The aim of this study was to evaluate the response of soybean to different types of artificial injuries caused in its early stages of development. The experiments were carried out at Embrapa Agropecuária Oeste using the cultivars FTS Campo Mourão and BRS Potência. These cultivars were submitted to nine treatments of artificial injuries, as follow: 1) removal of one cotyledon; 2) removal of two cotyledons; 3) removal of two cotyledons and one unifoliate leaf; 4) removal of two cotyledons and two unifoliate leaves; 5) removal of one unifoliate leaf, 6) removal of two unifoliate leaves; 7) cut below the unifoliate leaves; 8) cut below the trifoliate bud; 9) untreated (without injury). The plant height, the number of pods/plant and fresh weight of aerial part in Campo Mourão cultivar were lower than that observed with the Potência cultivar. There was also reduction of the plant height in the treatments 3, 4, 6 and 7 when compared to the control (without injury). The grain yield (Kg ha-1) was similar in both cultivars and was not influenced by the different types of injuries applied in plants of both cultivars. The weight of 100 seeds (g) was higher in cultivar Campo Mourão when compared to Potência cultivar. Regardless of the types of injuries that are caused, the plants have resilience to damage.

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