scholarly journals Forward and feedback regulation of cyclic steroid production in Drosophila melanogaster

Development ◽  
2014 ◽  
Vol 141 (20) ◽  
pp. 3955-3965 ◽  
Author(s):  
J.-P. Parvy ◽  
P. Wang ◽  
D. Garrido ◽  
A. Maria ◽  
C. Blais ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Feedback Regulation ◽  
Steroid Production

scholarly journals Cross-Regulation among the Polycomb Group Genes in Drosophila melanogaster

2004 ◽  
Vol 24 (17) ◽  
pp. 7737-7747 ◽  
Author(s):  
Janann Y. Ali ◽  
Welcome Bender
Keyword(s):  
Drosophila Melanogaster ◽  
Feedback Regulation ◽  
Polycomb Group ◽  
Negative Feedback Regulation ◽  
Polycomb Group Genes ◽  
Large Size ◽  
Evolutionarily Conserved ◽  
Positive Regulators ◽  
Core Components

ABSTRACT Genes of the Polycomb group in Drosophila melanogaster function as long-term transcriptional repressors. A few members of the group encode proteins found in two evolutionarily conserved chromatin complexes, Polycomb repressive complex 1 (PRC1) and the ESC-E(Z) complex. The majority of the group, lacking clear biochemical functions, might be indirect regulators. The transcript levels of seven Polycomb group genes were assayed in embryos mutant for various other genes in the family. Three Polycomb group genes were identified as upstream positive regulators of the core components of PRC1. There is also negative feedback regulation of some PRC1 core components by other PRC1 genes. Finally, there is positive regulation of PRC1 components by the ESC-E(Z) complex. These multiple pathways of cross-regulation help to explain the large size of the Polycomb group family of genes, but they complicate the genetic analysis of any single member.

scholarly journals Ecdysone-dependent feedback regulation of prothoracicotropic hormone controls the timing of developmental maturation

Development ◽  
2020 ◽  
Vol 147 (14) ◽  
pp. dev188110 ◽  
Author(s):  
Christian F. Christensen ◽  
Takashi Koyama ◽  
Stanislav Nagy ◽  
E. Thomas Danielsen ◽  
Michael J. Texada ◽  
...  
Keyword(s):  
Larval Development ◽  
Feedback Regulation ◽  
Neuroendocrine System ◽  
Ecdysone Receptor ◽  
Feedback Circuit ◽  
Steroid Production ◽  
Prothoracicotropic Hormone ◽  
Adult Transition ◽  
Developmental Maturation

ABSTRACTThe activation of a neuroendocrine system that induces a surge in steroid production is a conserved initiator of the juvenile-to-adult transition in many animals. The trigger for maturation is the secretion of brain-derived neuropeptides, yet the mechanisms controlling the timely onset of this event remain ill-defined. Here, we show that a regulatory feedback circuit controlling the Drosophila neuropeptide Prothoracicotropic hormone (PTTH) triggers maturation onset. We identify the Ecdysone Receptor (EcR) in the PTTH-expressing neurons (PTTHn) as a regulator of developmental maturation onset. Loss of EcR in these PTTHn impairs PTTH signaling, which delays maturation. We find that the steroid ecdysone dose-dependently affects Ptth transcription, promoting its expression at lower concentrations and inhibiting it at higher concentrations. Our findings indicate the existence of a feedback circuit in which rising ecdysone levels trigger, via EcR activity in the PTTHn, the PTTH surge that generates the maturation-inducing ecdysone peak toward the end of larval development. Because steroid feedback is also known to control the vertebrate maturation-inducing hypothalamic-pituitary-gonadal axis, our findings suggest an overall conservation of the feedback-regulatory neuroendocrine circuitry that controls the timing of maturation initiation.

Influence of neonatal hemicastration on in-vitro secretion of inhibin, gonadotrophins and testicular steroids in male rats

1985 ◽  
Vol 106 (2) ◽  
pp. 259-265 ◽  
Author(s):  
A. M. Ultee-van Gessel ◽  
F. G. Leemborg ◽  
F. H. de Jong ◽  
H. J. van der Molen
Keyword(s):  
Sertoli Cells ◽  
Leydig Cells ◽  
Feedback Regulation ◽  
Male Rats ◽  
Steroid Production ◽  
Pituitary Secretion ◽  
Lh Releasing Hormone ◽  
Testicular Steroids

ABSTRACT Pituitary secretion of FSH in male animals is regulated, at least partly, by a protein hormone, inhibin, which is produced by Sertoli cells in the testes. To establish at which age the role of testicular inhibin in the regulation of FSH secretion becomes apparent, groups of male rats were hemicastrated or sham-operated on day 1 of life and pituitary and testicular function were investigated in vitro at 21, 42 or 63 days of age. Testis weights were increased in hemicastrated rats at all ages studied. Peripheral concentrations of gonadotrophins generally showed a good correlation with the concentrations of FSH and LH measured in the medium of hemipituitary glands which were incubated in vitro at 37 °C in the absence or presence of LH-releasing hormone. Peripheral testosterone concentrations in hemicastrated animals were not significantly different from those in sham-operated rats at all ages studied. Steroid production by Leydig cells in vitro was not significantly influenced by hemicastration. The secretion of inhibin by Sertoli cells from 21-day-old hemicastrated rats was decreased while Sertoli cells from 42- and 63-day-old hemicastrated animals secreted slightly but not significantly more inhibin than Sertoli cells from sham-operated rats. It is concluded that although compensatory increases of testosterone and inhibin production at later ages make it difficult to draw conclusions about the relative importance of inhibin in the feedback regulation of FSH secretion at different ages, it is likely that inhibin plays a role in the feedback of FSH in immature, rather than in mature male rats. J. Endocr. (1985) 106, 259–265

Author response for "Location and arrangement of campaniform sensilla in Drosophila melanogaster"

2020 ◽  
Author(s):  
Gesa F. Dinges ◽  
Alexander S. Chockley ◽  
Till Bockemühl ◽  
Kei Ito ◽  
Alexander Blanke ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Author Response ◽  
Campaniform Sensilla

Live Confocal Analysis of Fertilization and Early Development

2001 ◽  
Vol 7 (S2) ◽  
pp. 1012-1013
Author(s):  
Uyen Tram ◽  
William Sullivan
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
Real Time ◽  
Early Development ◽  
Fluorescent Probes ◽  
Primary Defect ◽  
Fluorescent Analysis ◽  
Dynamic Event ◽  
Enormous Amount ◽  
Fluorescent Studies

Embryonic development is a dynamic event and is best studied in live animals in real time. Much of our knowledge of the early events of embryogenesis, however, comes from immunofluourescent analysis of fixed embryos. While these studies provide an enormous amount of information about the organization of different structures during development, they can give only a static glimpse of a very dynamic event. More recently real-time fluorescent studies of living embryos have become much more routine and have given new insights to how different structures and organelles (chromosomes, centrosomes, cytoskeleton, etc.) are coordinately regulated. This is in large part due to the development of commercially available fluorescent probes, GFP technology, and newly developed sensitive fluorescent microscopes. For example, live confocal fluorescent analysis proved essential in determining the primary defect in mutations that disrupt early nuclear divisions in Drosophila melanogaster. For organisms in which GPF transgenics is not available, fluorescent probes that label DNA, microtubules, and actin are available for microinjection.

Apoptosis and development

2003 ◽  
Vol 39 ◽  
pp. 11-24 ◽  
Author(s):  
Justin V McCarthy
Keyword(s):  
Drosophila Melanogaster ◽  
Mammalian Cells ◽  
Cell Number ◽  
Model Organisms ◽  
Biological Processes ◽  
Nematode Caenorhabditis Elegans ◽  
Apoptotic Pathway ◽  
Genetic Pathways ◽  
Evolutionarily Conserved ◽  
Multicellular Organisms

Apoptosis is an evolutionarily conserved process used by multicellular organisms to developmentally regulate cell number or to eliminate cells that are potentially detrimental to the organism. The large diversity of regulators of apoptosis in mammalian cells and their numerous interactions complicate the analysis of their individual functions, particularly in development. The remarkable conservation of apoptotic mechanisms across species has allowed the genetic pathways of apoptosis determined in lower species, such as the nematode Caenorhabditis elegans and the fruitfly Drosophila melanogaster, to act as models for understanding the biology of apoptosis in mammalian cells. Though many components of the apoptotic pathway are conserved between species, the use of additional model organisms has revealed several important differences and supports the use of model organisms in deciphering complex biological processes such as apoptosis.

Insights into amyloid disease from fly models

2014 ◽  
Vol 56 ◽  
pp. 69-83 ◽  
Author(s):  
Ko-Fan Chen ◽  
Damian C. Crowther
Keyword(s):  
Drosophila Melanogaster ◽  
Neurodegenerative Disorders ◽  
Amyloid Β ◽  
Amyloid Β Peptide ◽  
Disease Pathogenesis ◽  
Amyloid Aggregates ◽  
Aβ Amyloid ◽  
Polypeptide Chains ◽  
Amyloid Diseases

The formation of amyloid aggregates is a feature of most, if not all, polypeptide chains. In vivo modelling of this process has been undertaken in the fruitfly Drosophila melanogaster with remarkable success. Models of both neurological and systemic amyloid diseases have been generated and have informed our understanding of disease pathogenesis in two main ways. First, the toxic amyloid species have been at least partially characterized, for example in the case of the Aβ (amyloid β-peptide) associated with Alzheimer's disease. Secondly, the genetic underpinning of model disease-linked phenotypes has been characterized for a number of neurodegenerative disorders. The current challenge is to integrate our understanding of disease-linked processes in the fly with our growing knowledge of human disease, for the benefit of patients.

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