scholarly journals Regulatory logic of neuronal diversity: Terminal selector genes and selector motifs

2008 ◽  
Vol 105 (51) ◽  
pp. 20067-20071 ◽  
Author(s):  
O. Hobert
Keyword(s):  
Neuronal Diversity ◽  
Selector Genes

scholarly journals The L1-dependant and Pol III transcribed Alu retrotransposon, from its discovery to innate immunity

2021 ◽  
Vol 48 (3) ◽  
pp. 2775-2789
Author(s):  
Ludwig Stenz
Keyword(s):  
Human Genome ◽  
Viral Infections ◽  
De Novo ◽  
Current Knowledge ◽  
Innate Immune ◽  
De Novo Mutation ◽  
Neuronal Diversity ◽  
Alu Sequences ◽  
Pol Iii ◽  
The Brain

AbstractThe 300 bp dimeric repeats digestible by AluI were discovered in 1979. Since then, Alu were involved in the most fundamental epigenetic mechanisms, namely reprogramming, pluripotency, imprinting and mosaicism. These Alu encode a family of retrotransposons transcribed by the RNA Pol III machinery, notably when the cytosines that constitute their sequences are de-methylated. Then, Alu hijack the functions of ORF2 encoded by another transposons named L1 during reverse transcription and integration into new sites. That mechanism functions as a complex genetic parasite able to copy-paste Alu sequences. Doing that, Alu have modified even the size of the human genome, as well as of other primate genomes, during 65 million years of co-evolution. Actually, one germline retro-transposition still occurs each 20 births. Thus, Alu continue to modify our human genome nowadays and were implicated in de novo mutation causing diseases including deletions, duplications and rearrangements. Most recently, retrotransposons were found to trigger neuronal diversity by inducing mosaicism in the brain. Finally, boosted during viral infections, Alu clearly interact with the innate immune system. The purpose of that review is to give a condensed overview of all these major findings that concern the fascinating physiology of Alu from their discovery up to the current knowledge.

Regulation of proboscipedia in Drosophila by Homeotic Selector Genes

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 183-194
Author(s):  
Douglas B Rusch ◽  
Thomas C Kaufman
Keyword(s):  
Expression Pattern ◽  
Regulatory Element ◽  
Polycomb Group ◽  
Accumulation Pattern ◽  
Cis Acting ◽  
Polycomb Group Genes ◽  
Gap Genes ◽  
Combined Action ◽  
Selector Genes

Abstract The gene proboscipedia (pb) is a member of the Antennapedia complex in Drosophila and is required for the proper specification of the adult mouthparts. In the embryo, pb expression serves no known function despite having an accumulation pattern in the mouthpart anlagen that is conserved across several insect orders. We have identified several of the genes necessary to generate this embryonic pattern of expression. These genes can be roughly split into three categories based on their time of action during development. First, prior to the expression of pb, the gap genes are required to specify the domains where pb may be expressed. Second, the initial expression pattern of pb is controlled by the combined action of the genes Deformed (Dfd), Sex combs reduced (Scr), cap'n'collar (cnc), and teashirt (tsh). Lastly, maintenance of this expression pattern later in development is dependent on the action of a subset of the Polycomb group genes. These interactions are mediated in part through a 500-bp regulatory element in the second intron of pb. We further show that Dfd protein binds in vitro to sequences found in this fragment. This is the first clear demonstration of autonomous positive cross-regulation of one Hox gene by another in Drosophila melanogaster and the binding of Dfd to a cis-acting regulatory element indicates that this control might be direct.

Sequence of the Tribolium castaneum Homeotic Complex: The Region Corresponding to the Drosophila melanogaster Antennapedia Complex

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1067-1074
Author(s):  
Susan J Brown ◽  
John P Fellers ◽  
Teresa D Shippy ◽  
Elizabeth A Richardson ◽  
Mark Maxwell ◽  
...  
Keyword(s):  
Tribolium Castaneum ◽  
Hox Genes ◽  
Transcription Unit ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Selector Genes ◽  
Homeotic Selector Genes ◽  
Encoding Genes ◽  
Single Cluster ◽  
Homeotic Selector

Abstract The homeotic selector genes of the red flour beetle, Tribolium castaneum, are located in a single cluster. We have sequenced the region containing the homeotic selector genes required for proper development of the head and anterior thorax, which is the counterpart of the ANTC in Drosophila. This 280-kb interval contains eight homeodomain-encoding genes, including single orthologs of the Drosophila genes labial, proboscipedia, Deformed, Sex combs reduced, fushi tarazu, and Antennapedia, as well as two orthologs of zerknüllt. These genes are all oriented in the same direction, as are the Hox genes of amphioxus, mice, and humans. Although each transcription unit is similar to its Drosophila counterpart in size, the Tribolium genes contain fewer introns (with the exception of the two zerknüllt genes), produce shorter mRNAs, and encode smaller proteins. Unlike the ANTC, this region of the Tribolium HOMC contains no additional genes.

An expansion of the non-coding genome and its regulatory potential underlies vertebrate neuronal diversity

Neuron ◽  
2021 ◽  
Author(s):  
Michael Closser ◽  
Yuchun Guo ◽  
Ping Wang ◽  
Tulsi Patel ◽  
Sumin Jang ◽  
...  
Keyword(s):  
Neuronal Diversity ◽  
Regulatory Potential

Smoothened-mediated Hedgehog signalling is required for the maintenance of the anterior-posterior lineage restriction in the developing wing of Drosophila

Development ◽  
1997 ◽  
Vol 124 (20) ◽  
pp. 4053-4063 ◽  
Author(s):  
S.S. Blair ◽  
A. Ralston
Keyword(s):  
Gene Expression ◽  
Cellular Mechanisms ◽  
Hedgehog Signalling ◽  
Compartment Boundary ◽  
Complex Process ◽  
Normal Site ◽  
Selector Genes ◽  
Signalling Models ◽  
To Receive ◽  
Anterior Posterior

It is thought that the posterior expression of the ‘selector’ genes engrailed and invected control the subdivision of the growing wing imaginal disc of Drosophila into anterior and posterior lineage compartments. At present, the cellular mechanisms by which separate lineage compartments are maintained are not known. Most models have assumed that the presence or absence of selector gene expression autonomously drives the expression of compartment-specific adhesion or recognition molecules that inhibit intermixing between compartments. However, our present understanding of Hedgehog signalling from posterior to anterior cells raises some interesting alternative models based on a cell's response to signalling. We show here that anterior cells that lack smoothened, and thus the ability to receive the Hedgehog signal, no longer obey a lineage restriction in the normal position of the anterior-posterior boundary. Rather these clones extend into anatomically posterior territory, without any changes in engrailed/invected gene expression. We have also examined clones lacking both en and inv; these too show complex behaviors near the normal site of the compartment boundary, and do not always cross entirely into anatomically anterior territory. Our results suggest that compartmentalization is a complex process involving intercompartmental signalling; models based on changes in affinity or growth will be discussed.

scholarly journals Coupling progenitor and neuronal diversity in the developing neocortex

FEBS Letters ◽  
2017 ◽  
Vol 591 (24) ◽  
pp. 3960-3977 ◽  
Author(s):  
Subashika Govindan ◽  
Denis Jabaudon
Keyword(s):  
Neuronal Diversity ◽  
Developing Neocortex

scholarly journals Variation in olfactory neuron repertoires is genetically controlled and environmentally modulated

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Ximena Ibarra-Soria ◽  
Thiago S Nakahara ◽  
Jingtao Lilue ◽  
Yue Jiang ◽  
Casey Trimmer ◽  
...  
Keyword(s):  
Olfactory Receptor ◽  
Sensory System ◽  
Dependent Manner ◽  
Olfactory Neuron ◽  
Neuronal Diversity ◽  
Cis Acting ◽  
Genetic And Environmental Factors ◽  
Or Gene ◽  
Different Strains ◽  
Subtype Distribution

The mouse olfactory sensory neuron (OSN) repertoire is composed of 10 million cells and each expresses one olfactory receptor (OR) gene from a pool of over 1000. Thus, the nose is sub-stratified into more than a thousand OSN subtypes. Here, we employ and validate an RNA-sequencing-based method to quantify the abundance of all OSN subtypes in parallel, and investigate the genetic and environmental factors that contribute to neuronal diversity. We find that the OSN subtype distribution is stereotyped in genetically identical mice, but varies extensively between different strains. Further, we identify cis-acting genetic variation as the greatest component influencing OSN composition and demonstrate independence from OR function. However, we show that olfactory stimulation with particular odorants results in modulation of dozens of OSN subtypes in a subtle but reproducible, specific and time-dependent manner. Together, these mechanisms generate a highly individualized olfactory sensory system by promoting neuronal diversity.

scholarly journals The Hunchback temporal transcription factor determines motor neuron axon and dendrite targeting in Drosophila

2019 ◽  
Author(s):  
Austin Q. Seroka ◽  
Chris Q. Doe
Keyword(s):  
Transcription Factor ◽  
Motor Neurons ◽  
Neuronal Diversity ◽  
Molecular Identity ◽  
Extrinsic Cues ◽  
Circuit Development ◽  
Temporal Identity ◽  
Morphological Differences ◽  
And Behavior ◽  
Circuit Formation

AbstractThe generation of neuronal diversity is essential for circuit formation and behavior. Morphological differences in sequentially born neurons could be due to intrinsic molecular identity specified by temporal transcription factors (henceforth called intrinsic temporal identity) or due to changing extrinsic cues. Here we use the Drosophila NB7-1 lineage to address this question. NB7-1 sequentially generates the U1-U5 motor neurons; each has a distinct intrinsic temporal identity due to inheritance of a different temporal transcription factor at time of birth. Here we show that the U1-U5 neurons project axons sequentially, followed by sequential dendrite extension. We misexpress the earliest temporal transcription factor, Hunchback, to create “ectopic” U1 neurons with an early intrinsic temporal identity but later birth-order. These ectopic U1 neurons have axon muscle targeting and dendrite neuropil targeting consistent with U1 intrinsic temporal identity, rather than their time of birth or differentiation. We conclude that intrinsic temporal identity plays a major role in establishing both motor axon muscle targeting and dendritic arbor targeting, which are required for proper motor circuit development.

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