scholarly journals Expression of Hey marks a subset of enteroendocrine cells in the Drosophila embryonic and larval midgut

2021 ◽  
Author(s):  
Emilia Skafida ◽  
Christos Delidakis ◽  
Maria Monastirioti
Keyword(s):  
Nervous System ◽  
Transcription Factor ◽  
Notch Signaling ◽  
Asymmetric Division ◽  
Enteroendocrine Cells ◽  
Larval Midgut ◽  
Mammalian Genomes ◽  
Low Levels ◽  
Newborn Neurons ◽  
Mother Cells

Hey is a conserved transcription factor of the bHLH-Orange family and it participates in the response to Notch signaling in certain tissues. Whereas three Hey paralogues exist in mammalian genomes, Drosophila possesses a single Hey gene. Fly Hey is expressed in the subset of newborn neurons that receive a Notch signal to differentiate them from their sibling cells after the asymmetric division of precursors called ganglion-mother-cells. We used a polyclonal anti-Hey serum and a GFP-tagged transgenic duplication of the Hey locus to examine its expression in tissues outside the nervous system in embryos and larvae. We detected robust Hey expression in the embryonic midgut primordium at the time of birth of enteroendocrine cells, identified by expression of Prospero. About half of the Pros-positive cells were also Hey positive at mid-embryogenesis. By the end of embryogenesis, most enteroendocrine cells had downregulated Hey expression, although it was still detectable at low levels after hatching. Low levels of Hey were also detected in subsets of the epithelial enterocytes at different times. Embryo enteroendocrine Hey expression was found to be Notch dependent. In late third-instar larvae, when few new enteroendocrine cells are born, novel Hey expression was detected in one cell of each sibling pair. In conclusion, Hey is strongly expressed in one of each pair of newly-born enteroendocrine cells. This is consistent with a hypothesis that embryonic enteroendocrine cells are born by an asymmetric division of a precursor, where Notch/Hey probably distinguish between the subtypes of these cells upon their differentiation.

scholarly journals A test of spatial temporal decoding mechanisms in the superior colliculus

2012 ◽  
Vol 107 (9) ◽  
pp. 2442-2452 ◽  
Author(s):  
Husam A. Katnani ◽  
A. J. Van Opstal ◽  
Neeraj J. Gandhi
Keyword(s):  
Nervous System ◽  
Motor Control ◽  
Eye Movements ◽  
Superior Colliculus ◽  
Motor Behavior ◽  
Saccadic Eye Movements ◽  
Population Coding ◽  
Population Activity ◽  
Low Levels

Population coding is a ubiquitous principle in the nervous system for the proper control of motor behavior. A significant amount of research is dedicated to studying population activity in the superior colliculus (SC) to investigate the motor control of saccadic eye movements. Vector summation with saturation (VSS) has been proposed as a mechanism for how population activity in the SC can be decoded to generate saccades. Interestingly, the model produces different predictions when decoding two simultaneous populations at high vs. low levels of activity. We tested these predictions by generating two simultaneous populations in the SC with high or low levels of dual microstimulation. We also combined varying levels of stimulation with visually induced activity. We found that our results did not perfectly conform to the predictions of the VSS scheme and conclude that the simplest implementation of the model is incomplete. We propose that additional parameters to the model might account for the results of this investigation.

scholarly journals The bHLH Transcription Factor NeuroD Governs Photoreceptor Genesis and Regeneration Through Delta-Notch Signaling

2015 ◽  
Vol 56 (12) ◽  
pp. 7496 ◽  
Author(s):  
Scott M. Taylor ◽  
Karen Alvarez-Delfin ◽  
Carole J. Saade ◽  
Jennifer L. Thomas ◽  
Ryan Thummel ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Notch Signaling ◽  
Bhlh Transcription Factor

Influence of ionizing radiations on the development of the nervous system

1967 ◽  
Vol 16 (3) ◽  
pp. 275-309 ◽  
Author(s):  
W. Geets
Keyword(s):  
Nervous System ◽  
Cerebral Cortex ◽  
Research Work ◽  
Low Doses ◽  
Embryonic Period ◽  
Clinical Observations ◽  
Functional Maturation ◽  
Maturation Stages ◽  
Mother Cells ◽  
Ionizing Radiations

SUMMARYThe first cellular differentiation in the process of segmentation leads to the embryonic period, the major organogenetic period for the nervous system. In man, it appears between the second and the eighth week after conception.During the foetal and perinatal periods, the nervous organization mainly develops at the cerebellum and cerebral cortex levels. The cerebrum functional maturation continues well beyond birth.Neuroblasts are the most widespread mother-cells in the developing nervous system during the embryonic period, but some are still to be found after birth.Animal experiment has demonstrated that ionizing radiations were able to disorganize neurogenesis in any of its maturation stages, even at very low doses. It is possible to establish a chronological table showing the anatomical or functional deformities in relation with the embryonic age at which rays have been given.It appears that in man the most dangerous period is between the beginning of the second and the end of the eighth week after conception. At that moment, pregnancy is often ignored and a dose of 20 to 40 r is sufficient to entail serious damages, such as microcephaly, protrusions of the brain or mental retardation. On drawing near to birth the foetal or neonatal nervous system of rodents or primates is still radiosensitive, especially at the cerebral cortex level and the consequences will be of a neurophysiologic or psychosensorial nature. Certain embryopathies or neurologic alterations would only be apparent in subsequent generations, following mutations induced into the mother-cells of the nervous system. Genetic deformities of the nervous system can also result from moderate irradiations of the gonads.Further to the precise experimental research work on the radiovulnerability of the embryonic or foetal nervous system of the animal, certain clinical observations are presented, which lead to similar conclusions.The atomic bombardments have caused numerous neurological trouble among the children who had been irradiated in utero. And the genetic effects are not yet perfectly known to-date.This set of experimental and clinical data must prompt us to be very careful when using ionizing radiations, even at low doses, in pregnant women and newborn.

scholarly journals Dissecting Hes-centered transcriptional networks in neural stem cell maintenance and tumorigenesis in Drosophila

2020 ◽  
Author(s):  
Srivathsa S. Magadi ◽  
Chrysanthi Voutyraki ◽  
Gerasimos Anagnostopoulos ◽  
Evanthia Zacharioudaki ◽  
Ioanna K. Poutakidou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Nervous System ◽  
Transcription Factor ◽  
Stem Cell ◽  
Neural Stem Cells ◽  
Cell Fate ◽  
Asymmetric Cell Division ◽  
Transcriptional Networks ◽  
Malignant Tumours ◽  
Stem Cell Maintenance

ABSTRACTNeural stem cells divide during embryogenesis and post embryonic development to generate the entire complement of neurons and glia in the nervous system of vertebrates and invertebrates. Studies of the mechanisms controlling the fine balance between neural stem cells and more differentiated progenitors have shown that in every asymmetric cell division progenitors send a Delta-Notch signal back to their sibling stem cells. Here we show that excessive activation of Notch or overexpression of its direct targets of the Hes family causes stem-cell hyperplasias in the Drosophila larval central nervous system, which can progress to malignant tumours after allografting to adult hosts. We combined transcriptomic data from these hyperplasias with chromatin occupancy data for Dpn, a Hes transcription factor, to identify genes regulated by Hes factors in this process. We show that the Notch/Hes axis represses a cohort of transcription factor genes. These are excluded from the stem cells and promote early differentiation steps, most likely by preventing the reversion of immature progenitors to a stem-cell fate. Our results suggest that Notch signalling sets up a network of mutually repressing stemness and anti-stemness transcription factors, which include Hes proteins and Zfh1, respectively. This mutual repression ensures robust transition to neuronal and glial differentiation and its perturbation can lead to malignant transformation.

scholarly journals Transcription factor TFCP2L1 patterns cells in the mouse kidney collecting ducts

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Max Werth ◽  
Kai M Schmidt-Ott ◽  
Thomas Leete ◽  
Andong Qiu ◽  
Christian Hinze ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Notch Signaling ◽  
Salt Water ◽  
Collecting Duct ◽  
Cell Types ◽  
Nephron Segments ◽  
Collecting Ducts ◽  
Atpase Subunits ◽  
Central Characteristic ◽  
Salt And Pepper

Although most nephron segments contain one type of epithelial cell, the collecting ducts consists of at least two: intercalated (IC) and principal (PC) cells, which regulate acid-base and salt-water homeostasis, respectively. In adult kidneys, these cells are organized in rosettes suggesting functional interactions. Genetic studies in mouse revealed that transcription factor Tfcp2l1 coordinates IC and PC development. Tfcp2l1 induces the expression of IC specific genes, including specific H+-ATPase subunits and Jag1. Jag1 in turn, initiates Notch signaling in PCs but inhibits Notch signaling in ICs. Tfcp2l1 inactivation deletes ICs, whereas Jag1 inactivation results in the forfeiture of discrete IC and PC identities. Thus, Tfcp2l1 is a critical regulator of IC-PC patterning, acting cell-autonomously in ICs, and non-cell-autonomously in PCs. As a result, Tfcp2l1 regulates the diversification of cell types which is the central characteristic of 'salt and pepper' epithelia and distinguishes the collecting duct from all other nephron segments.

scholarly journals The Drosophila couch potato gene: an essential gene required for normal adult behavior.

Genetics ◽  
1992 ◽  
Vol 131 (2) ◽  
pp. 365-375 ◽  
Author(s):  
H J Bellen ◽  
H Vaessin ◽  
E Bier ◽  
A Kolodkin ◽  
D D'Evelyn ◽  
...  
Keyword(s):  
Nervous System ◽  
Essential Gene ◽  
Flight Behavior ◽  
Regulatory Sequences ◽  
Adult Behavior ◽  
The Central Nervous System ◽  
Enhancer Detection ◽  
Dna Fragment ◽  
Mother Cells

Abstract Through enhancer detection screens we have isolated 14 insertions in an essential gene that is expressed in embryonic sensory mother cells (SMC), in most cells of the mature embryonic peripheral nervous system (PNS), and in glial cells of the PNS and the central nervous system (CNS). Embryos homozygote for amorphic alleles die, but show no obvious defects in their cuticle, PNS or CNS. The gene has been named couch potato (cpo) because several insertional alleles alter adult behavior. Homozygous hypomorphic cpo flies recover slowly from ether anaesthesia, show aberrant flight behavior, fail to move toward light and do not exhibit normal negative behavior. However, the flies are able to groom and walk, and some are able to fly when prodded, indicating that not all processes required for behavior are severely affected. A molecular analysis shows that the 14 insertions are confined to a few hundred nucleotides which probably contain key regulatory sequences of the gene. The orientation of these insertions and their position within this DNA fragment play an important role in the couch potato phenotype. In situ hybridization to whole mount embryos suggest that some insertions affect the levels of transcription of cpo in most cells in which it is expressed.

scholarly journals Growth Models of Positive Caregiving Behaviours and Concurrent Autonomic 
Activity in Caregivers and Children during a Challenging Puzzle Task: Replication and Extension

2020 ◽  
Author(s):  
Heidi Barkman ◽  
Ashley Allan ◽  
Marlee Salsbury ◽  
Erik L Knight ◽  
Christina Karns ◽  
...  
Keyword(s):  
Nervous System ◽  
Parasympathetic Nervous System ◽  
Dynamic Range ◽  
Growth Models ◽  
Multilevel Modelling ◽  
Emotional Expressions ◽  
Parasympathetic Nervous System Activity ◽  
Low Levels ◽  
Positive Caregiving ◽  
Puzzle Task

Caregivers exhibiting low levels of positive caregiving tend to have reduced dynamic range in high- frequency heart rate variability (HRV), an index of parasympathetic nervous system activity. Yet less is known about the involvement of the sympathetic nervous system, which may impact the plausible range of parasympathetic reactivity. Here, caregiver–child dyads completed resting assessments of HRV and pre-ejection period (PEP), followed by a videotaped puzzle task during which HRV was measured and observers coded the degree of caregivers’ positive emotionality. Multilevel modelling was employed to characterize task fluctuations in HRV as a function of resting PEP and caregivers’ positive emotional expressions. Higher frequency of caregiver positivity was associated with greater HRV reactivity in caregivers but not children. Increased caregiver positivity was correlated with longer resting PEP in children. These results replicate findings of greater caregiver parasympathetic flexibility during positive caregiving and extend those findings to children’s resting sympathetic activity.

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