An axial domain of HOM/Hox gene expression is formed by morphogenetic alignment of independently specified cell lineages in the leech Helobdella

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1839-1849 ◽  
Author(s):  
D. Nardelli-Haefliger ◽  
A.E. Bruce ◽  
M. Shankland
Keyword(s):  
Embryonic Stem ◽  
Cell Lineage ◽  
Homeobox Gene ◽  
Positional Information ◽  
The Other ◽  
Expression Domain ◽  
Hox Gene ◽  
Cell Lineages ◽  
High Level

The homeobox gene Lox2, a member of the HOM/Hox gene class, is expressed in a restricted domain along the anteroposterior (A-P) body axis of the leech Helobdella. The segmental tissues of the leech embryo arise from the parallel merger of five distinct and bilaterally paired cell lineages generated by embryonic stem cells or teloblasts. Injection of cell lineage tracers coupled with anti-LOX2 immunochemistry reveals that all five teloblast lineages generate central nervous system neurons that express the LOX2 protein, and that each lineage expresses LOX2 within a similar domain of body segments. Some lineally identified neurons display anti-LOX2 immunoreactivity over the entire expression domain, but the OM7 neuron has a distinctively high level of LOX2 expression, which is restricted to the seventh midbody ganglion. To ascertain the role of positional information in the axial patterning of LOX2 expression, we performed focal cell ablations that displaced one or another of the teloblast lineages out of segmental register with the other axial tissues. Such displacements brought about a corresponding shift in the LOX2 expression of the perturbed lineage, and had little or no effect on the LOX2 expression of the other, unperturbed lineages. This result indicates that the axial domain of LOX2 expression is not specified by positional cues acting coordinately across the various teloblast lineages, nor would it seem that the expression domain is imprinted from one lineage to the others. Rather, the different teloblast lineages acquire their axial patterns independently, and secondarily bring these patterns into alignment along the A-P axis through a process of morphogenetic assembly.

scholarly journals Successive specification of Drosophila neuroblasts NB 6-4 and NB 7-3 depends on interaction of the segment polarity genes wingless, gooseberry and naked cuticle

Development ◽  
2001 ◽  
Vol 128 (17) ◽  
pp. 3253-3261 ◽  
Author(s):  
Nirupama Deshpande ◽  
Rainer Dittrich ◽  
Gerhard M. Technau ◽  
Joachim Urban
Keyword(s):  
Cell Fate ◽  
Cell Lineage ◽  
Positional Information ◽  
Dorsoventral Patterning ◽  
Expression Domain ◽  
Direct Role ◽  
Segment Polarity Genes ◽  
Segment Polarity ◽  
Unique Identity

The Drosophila central nervous system derives from neural precursor cells, the neuroblasts (NBs), which are born from the neuroectoderm by the process of delamination. Each NB has a unique identity, which is revealed by the production of a characteristic cell lineage and a specific set of molecular markers it expresses. These NBs delaminate at different but reproducible time points during neurogenesis (S1-S5) and it has been shown for early delaminating NBs (S1/S2) that their identities depend on positional information conferred by segment polarity genes and dorsoventral patterning genes. We have studied mechanisms leading to the fate specification of a set of late delaminating neuroblasts, NB 6-4 and NB 7-3, both of which arise from the engrailed (en) expression domain, with NB 6-4 delaminating first. In contrast to former reports, we did not find any evidence for a direct role of hedgehog in the process of NB 7-3 specification. Instead, we present evidence to show that the interplay of the segmentation genes naked cuticle (nkd) and gooseberry (gsb), both of which are targets of wingless (wg) activity, leads to differential commitment to NB 6-4 and NB 7-3 cell fate. In the absence of either nkd or gsb, one NB fate is replaced by the other. However, the temporal sequence of delamination is maintained, suggesting that formation and specification of these two NBs are under independent control.

How to Combine Virtual and Reality in Archaeology Communication

2020 ◽  
pp. 245-258
Author(s):  
Caterina Paola Venditti ◽  
Paolo Mele
Keyword(s):  
Cultural Heritage ◽  
Mixed Reality ◽  
The Other ◽  
Static Models ◽  
Display Technology ◽  
Digital Archaeology ◽  
High Level ◽  
Individual Objects

Within digital archaeology, an important part is centered on technologies that allow representing, or replaying, ancient environments. It is a field where scientific competences' contribution to contents makes a difference, and pedagogical repercussion are stimulating. Among the other reality technologies, the Mixed Reality, giving the possibility to experience in front of the users' eyes both static models of individual objects and entire landscapes, it is increasingly used in archaeological contexts as display technology, with different purposes such as educational, informative, or simply for entertainment. This chapter provides a high-level overview about possible orientations and uses of this technology in cultural heritage, also sketching its use in gaming within the role of gaming itself in smart communication of archaeological contents and issues.

scholarly journals The role of organo-tissue barriers in the formation of a systemic inflammatory reaction and neutralize toxins in pancreatic necrosis, the choice of rational tactics surgical treatment

2011 ◽  
Vol 4 (1) ◽  
pp. 51-56
Author(s):  
Vladimir Grigoryevich Lubyanka ◽  
Victor Fedorovich Chernenko ◽  
Aleksandr Hrustevich Aliev ◽  
Andrey Nikolaevich Zharikov ◽  
Svetlana Aleksandrovna Yelchaninova ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Pancreatic Necrosis ◽  
The Other ◽  
Systemic Inflammatory Reaction ◽  
Organ Tissue ◽  
The One ◽  
High Level ◽  
Methods Of Treatment ◽  
Intensive Development

Despite the intensive development of the diagnosis and surgical treatment of pancreatic necrosis (PN), mortality remains high, reaching 30-50% or more. This is due, on the one hand, with insufficient study of the mechanisms pancreatogenic toxemia, generalized infection, manifestations of the Systemic Inflammatory Response (SIR) and the role of organ-tissue barriers in the neutralization of toxins (the liver, lungs, muscles and cellulate array), on the other hand, the ineffectiveness of drugs in their system application as a result of blocking organ microcirculation and limiting their availability. As a result, research has found evidence of the complexity of the SIR and the mechanisms of toxemia in the PN (enzymatic, metabolic and bacterial), which showed a high level of leukocytosis, the study of enzymes, especially when infected Mon, reflecting the morphological and functional liver damage, as the primary detoxification barrier pancreatogenic aggression. These humoral indicators can serve when they raise specific markers of the severity of toxemia and SIR. Application regional arterial drug therapy provider medicinal effect is in the region of defeat, can achieve better results in reducing mortality in Mon, compared with traditional methods of treatment.

scholarly journals COUNSELLING ON THE ROLE OF WOMEN IN THE IMPLEMENTATION OF THE CONCEPT OF WASATHIYAH (MODERATE) ISLAM

ICCD ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 269-272
Author(s):  
Elis Teti Rusmiati ◽  
Rajab Ritonga
Keyword(s):  
The Other ◽  
Full Understanding ◽  
Islamic World ◽  
Constructive Dialogue ◽  
The Family ◽  
The One ◽  
High Level ◽  
Correct Understanding ◽  
Muslim Scholars

The idea of the concept of Wasathiyah Islam (moderate Islam) reappeared in the High Level Consultation (Summit) of World Muslim Scholars and Intellectuals at the Bogor Palace, 1-3 May 2018. Wasathiyah Islam is perceived as a perspective that understands the position of Islam between two extreme opposite points: Fundamentalist and radical on the one hand, and liberal and permissive on the other. Women are the party mostdefeated by Islamic fundamentalists and most disadvantaged in the application of rigid Islamic sharia in various places in the Islamic world. In connection with concept of Wasathiyah Islam, women have monitoring ability that can promote constructive dialogue and provide understanding, both in the family and in the community. Therefore, women need to be equipped with a full understanding of the concept of WasathiyahIslam, because misleading understanding can foster religious radicalism on the one hand, and permissive attitudes will dwarf the understanding of religion on the other. The method used in this counselling includes several stages: 1) survey; 2) module making; 3) counselling; 4) interactive dialogue; 5) evaluation. The results of the counselling showed that after the training, participants enhanced their knowledge about the concept ofWasathiyah Islam. They began to realize that they had an important role in instilling a correct understanding of Wasathiyah Islam towards their families and communities.

Control of phyllotaxy in maize by the abphyl1 gene

Development ◽  
1999 ◽  
Vol 126 (2) ◽  
pp. 315-323 ◽  
Author(s):  
D. Jackson ◽  
S. Hake
Keyword(s):  
Apical Meristem ◽  
General Structure ◽  
Homeobox Gene ◽  
The Other ◽  
Shoot Meristem ◽  
Regular Pattern ◽  
Expression Domain ◽  
Geometric Patterns ◽  
Maize Plants ◽  
Shoot Meristems

Organogenesis in plants occurs at the shoot apical meristem, a group of indeterminate stem cells that are organized during embryogenesis. Regulated initiation of leaves or flowers from the shoot meristem gives rise to the familiar geometric patterns observed throughout the plant kingdom. The mechanism by which these patterns, termed phyllotaxies, are generated, remains unclear. Maize plants initiate leaves singly, alternating from one side to the other in a regular pattern. Here we describe a recessive maize mutant, abphyl1, that initiates leaves in opposite pairs, in a pattern termed decussate phyllotaxy. The decussate shoot meristems are larger than normal throughout development, though the general structure and organization of the meristem is not altered. abph1 mutants are first distinguished during embryogenesis, prior to true leaf initiation, by a larger shoot meristem and coincident larger expression domain of the homeobox gene knotted1. Therefore, the abph1 gene regulates morphogenesis in the embryo, and plays a role in determining the phyllotaxy of the shoot.

scholarly journals Lack of influence of low temperature, light and growth substances on phytochrome resynthesis in coleoptiles of irradiated oat seedlings

2014 ◽  
Vol 53 (2) ◽  
pp. 271-278
Author(s):  
Jan Kopcewicz ◽  
Mariusz Cymerski ◽  
Kazimierz Madela
Keyword(s):  
Low Temperature ◽  
Large Fraction ◽  
Elongation Growth ◽  
The Other ◽  
High Rate ◽  
Growth Substances ◽  
Etiolated Seedlings ◽  
High Level ◽  
Very High

The photoconversion of phytochrome P<sub>R</sub> into the P<sub>FR</sub> form causes at the same time the destruction of the initial large fraction of phytochrome found in the coleoptiles of etiolated oat seedlings. Factors such as low temperature, light of different wavelengths or growth substances are not capable of preventing the progressive destruction and restore the synthesis of phytochrome. Thus an abnormally high level of phytochrome is found only in etiolated seedlings. Such seedlings, on the other hand, are characterized by a very high rate of elongation growth. The role of phytochrome in the control of deetiolation of seedlings is discussed.

scholarly journals social and cultural issues in ‘The Slave Yards’

Twejer ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 807-850
Author(s):  
Abdullah Bairam Younis ◽  
◽  
Amir Ahmed Hamad Amin ◽  
Keyword(s):  
Key Words ◽  
The Other ◽  
Narrative Form ◽  
Social Meaning ◽  
The Novel ◽  
Cultural Issues ◽  
Popular Songs ◽  
The Social ◽  
High Level

The novel of ‘The Slave Yards’ by Najwa Bin Shatwan, is not only a biographic of his daughter Atiqa, in which they were lived through depression, and misery. Also, it is not a narration of Libya’s history, while the novel is about the intellectual, social and cultural issues. The author tried to present that matters in a high level. In general, that novel can be distinguished with the other novels in numerous social references, and the ability to identify them in a narrative form, in which the social references are related to the relationships of individuals with each other. The author tried to control the events, and to link the role of the characters to each other. Also, the author presents the events which they are imposed by reality, and in any changes their real social meaning will be changed as well. In this regard, we highlight those issues into two points: the first one is highlighting the traditions and customs, and the second one is highlighting the folklore songs, myths, and religious places. Key Words: Slave Carpets, Social references, Myths, Popular Songs, Customs

Fine-Grain Episodic Memory Processes in Cognitive Control

2013 ◽  
Vol 221 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Erik M. Altmann
Keyword(s):  
Cognitive Control ◽  
Episodic Memory ◽  
Proactive Interference ◽  
Task Switching ◽  
The Other ◽  
Memory Processes ◽  
Fine Grain ◽  
Integral Role ◽  
High Level

Previous task-switching research raises a question concerning the role of episodic memory processes in cognitive control. The question is framed by the contrast between two procedures, explicit cuing and randomized runs, one of which presents a task cue perceptually on every trial and the other of which involves uncued trials. The present study compares performance across these procedures. Performance errors sensitive to errors in focusing on the correct task were higher under explicit-cuing conditions than under randomized-runs conditions, consistent with a high level of proactive interference from old task information. The results support an account in which control codes stored in episodic memory play an integral role in cognitive control, even under conditions in which all information needed for performance is perceptually available.

Lox2, a putative leech segment identity gene, is expressed in the same segmental domain in different stem cell lineages

Development ◽  
1992 ◽  
Vol 116 (3) ◽  
pp. 697-710 ◽  
Author(s):  
D. Nardelli-Haefliger ◽  
M. Shankland
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Embryonic Stem ◽  
Cell Lineage ◽  
Gene Products ◽  
Cell Lineages ◽  
Stem Cell Lineage ◽  
Hybridization Reaction ◽  
Cell Segment

The segmented tissues of the adult leech arise from a set of five, bilaterally paired embryonic stem cells via a stereotyped sequence of cell lineage. Individual segments exhibit unique patterns of cell differentiation, and previous studies have suggested that each stem cell lineage establishes at least some aspects of its own segmental specificity autonomously. In this paper, we describe a putative leech segment identity gene, Lox2, and examine its expression in the various stem cell lineages. Both sequence analysis and the segmental pattern of Lox2 expression suggest a specific homology to the fruitfly segment identity genes Ubx and abdA. In situ hybridization reveals a cellular accumulation of Lox2 RNA over a contiguous domain of 16 midbody segments (M6-M21), including postmitotic neurons, muscles and the differentiating genitalia. Lox2 transcripts were not detected at the stage when segment identities are first established, suggesting that Lox2 gene products may not be part of the initial specification process. Individual stem cell lineages were labeled by intracellular injection of fluorescent tracers, and single cell colocalization of lineage tracer and hybridization reaction product revealed expression of Lox2 RNA in the progeny of four different stem cells. The segmental domain of Lox2 RNA was very similar in the various stem cell lineages, despite the fact that some stem cells generate one founder cell/segment, whereas other stem cells generate two founder cells/segment.

The role of cell lineage in development

1985 ◽  
Vol 312 (1153) ◽  
pp. 3-19 ◽  
Keyword(s):  
Cell Fate ◽  
Cell Lineage ◽  
Early Embryo ◽  
Embryonic Cell ◽  
Evolutionary Divergence ◽  
Causative Role ◽  
Embryonic Cells ◽  
Developmental Potential ◽  
Cell Lineages

Studies of the role of cell lineage in development began in the latter part of the 19th century, fell into decline in the early part of the 20th, and were revived about 20 years ago. This recent revival was accompanied by the introduction of new and powerful analytical techniques. Concepts of importance for cell lineage studies include the principal division modes by which a cell may give rise to its descendant clone (proliferative, stem cell and diversifying); developmental determinacy , or indeterminacy , which refer to the degree to which the normal cleavage pattern of the early embryo and the developmental fate of its individual cells is, or is not, the same in specimen after specimen; commitment , which refers to the restriction of the developmental potential of a pluripotent embryonic cell; and equivalence group , which refers to two or more equivalently pluripotent cell clones that normally take on different fates but of which under abnormal conditions one clone can take on the fate of another. Cell lineage can be inferred to have a causative role in developmental cell fate in embryos in which induced changes in cell division patterns lead to changes in cell fate. Moreover, such a causative role of cell lineage is suggested by cases where homologous cell types characteristic of a symmetrical and longitudinally metameric body plan arise via homologous cell lineages. The developmental pathways of commitment to particular cell fates proceed according to a mixed typologic and topographic hierarchy, which appears to reflect an evolutionary compromise between maximizing the ease of ordering the spatial distribution of the determinants of commitment and minimizing the need for migration of differentially committed embryonic cells. Comparison of the developmental cell lineages in leeches and insects indicates that the early course of embryogenesis is radically different in these phyletically related taxa. This evolutionary divergence of the course of early embryogenesis appears to be attributable to an increasing prevalence of polyclonal rather than monoclonal commitment in the phylogenetic line leading from an annelid-like ancestor to insects.

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