A chicken achaete-scute homolog (CASH-1) is expressed in a temporally and spatially discrete manner in the developing nervous system

Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 769-783 ◽  
Author(s):  
C.L. Jasoni ◽  
M.B. Walker ◽  
M.D. Morris ◽  
T.A. Reh

We have identified a basic helix-loop-helix encoding cDNA from embryonic chicken retina which shares sequence similarity with the achaete-scute family of genes of Drosophila. The deduced amino acid sequence of this chicken achaete-scute homolog (CASH-1) is identical, over the region encoding the basic helix-loop-helix domain, to the recently identified mammalian achaete-scute homolog (MASH-1) and to the Xenopus homolog (XASH1), and 70% identical, over the same region, to Drosophila achaete-scute complex members. The expression of CASH-1 is restricted to subsets of neuronal progenitor cells in the developing chicken nervous system, similar in distribution to that reported for MASH-1 and XASH1. In addition, in situ localization in the retina reveals a dynamic character of expression of the gene in a particular region of the CNS, and suggests that the expression of CASH-1 may be important in defining a particular stage in the progenitor cell necessary for the differentiation of particular neuronal phenotypes.

Development ◽  
1997 ◽  
Vol 124 (17) ◽  
pp. 3263-3272 ◽  
Author(s):  
T. Roztocil ◽  
L. Matter-Sadzinski ◽  
C. Alliod ◽  
M. Ballivet ◽  
J.M. Matter

Genes encoding transcription factors of the helix-loop-helix family are essential for the development of the nervous system in Drosophila and vertebrates. Screens of an embryonic chick neural cDNA library have yielded NeuroM, a novel neural-specific helix-loop-helix transcription factor related to the Drosophila proneural gene atonal. The NeuroM protein most closely resembles the vertebrate NeuroD and Nex1/MATH2 factors, and is capable of transactivating an E-box promoter in vivo. In situ hybridization studies have been conducted, in conjunction with pulse-labeling of S-phase nuclei, to compare NeuroM to NeuroD expression in the developing nervous system. In spinal cord and optic tectum, NeuroM expression precedes that of NeuroD. It is transient and restricted to cells lining the ventricular zone that have ceased proliferating but have not yet begun to migrate into the outer layers. In retina, NeuroM is also transiently expressed in cells as they withdraw from the mitotic cycle, but persists in horizontal and bipolar neurons until full differentiation, assuming an expression pattern exactly complementary to NeuroD. In the peripheral nervous system, NeuroM expression closely follows cell proliferation, suggesting that it intervenes at a similar developmental juncture in all parts of the nervous system. We propose that availability of the NeuroM helix-loop-helix factor defines a new stage in neurogenesis, at the transition between undifferentiated, premigratory and differentiating, migratory neural precursors.


1989 ◽  
Vol 109 (5) ◽  
pp. 2441-2453 ◽  
Author(s):  
D J Montell ◽  
C S Goodman

In a previous study, we described the cloning of the genes encoding the three subunits of Drosophila laminin, a substrate adhesion molecule, and the cDNA sequence of the B1 subunit (Montell and Goodman, 1988). This analysis revealed the similarity of Drosophila laminin with the mouse and human complexes in subunit composition, domain structure, and amino acid sequence. In this paper, we report the deduced amino acid sequence of the B2 subunit. We then describe the expression and tissue distribution of the three subunits of laminin during Drosophila embryogenesis using both in situ hybridization and immunolocalization techniques, with particular emphasis on its expression in and around the developing nervous system.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Alexander J. Hron ◽  
Atsushi Asakura

Rhabdomyosarcoma (RMS) is an aggressive family of soft tissue tumors that most commonly manifests in children. RMS variants express several skeletal muscle markers, suggesting myogenic stem or progenitor cell origin of RMS. In this review, the roles of both recently identified and well-established microRNAs in RMS are discussed and summarized in a succinct, tabulated format. Additionally, the subtypes of RMS are reviewed along with the involvement of basic helix-loop-helix (bHLH) proteins, Pax proteins, and microRNAs in normal and pathologic myogenesis. Finally, the current and potential future treatment options for RMS are outlined.


1996 ◽  
Vol 16 (10) ◽  
pp. 5865-5875 ◽  
Author(s):  
M Ema ◽  
M Morita ◽  
S Ikawa ◽  
M Tanaka ◽  
Y Matsuda ◽  
...  

From a cDNA library of mouse skeletal muscle, we have isolated mouse Sim1 (mSim1) cDNA encoding a polypeptide of 765 amino acids with striking amino acid identify in basic helix-loop-helix (89% identify) and PAS (89 % identify) domains to previously identified mSim2, although the carboxy-terminal third of the molecule did not show any similarity to mSim2 or Drosophila Sim (dSim). Yeast two-hybrid analysis and coimmunoprecipitation experiments demonstrated that both of the mSim gene products interacted with Arnt even more efficiently than AhR, a natural partner of Arnt, suggesting a functional cooperativity with Arnt. In sharp contrast with dSim having transcriptional-enhancing activity in the carboxy-terminal region, the two mSims possessed a repressive activity toward Arnt in the heterodimer complex. This is the first example of bHLH-PAS proteins with transrepressor activity, although some genetic data suggest that dSim plays a repressive role in gene expression (Z. Chang, D. Price, S. Bockheim, M. J. Boedigheimer, R. Smith, and A. Laughon, Dev. Biol. 160:315-322, 1993; D. M. Mellerick and M. Nirenberg, Dev. Biol. 171:306-316, 1995). Whole-mount in situ hybridization showed restricted and characteristic expression patterns of the two mSim mRNAs in various tissues and organs during embryogenesis, such as those for the somite, the nephrogenic cord, and the mesencephalon (for mSim1) and those for the diencephalon, branchial arches, and limbs (for mSim2). From sequence similarity and chromosomal localization, it is concluded that mSim2 is an ortholog of hSim2, which is proposed to be a candidate gene responsible for Down's syndrome. The sites of mSim2 expression showed an overlap with the affected regions of the syndrome, further strengthening involvement of mSim2 in Down's syndrome.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Antonella Lauri ◽  
Paola Bertucci ◽  
Detlev Arendt

In vertebrates, neurotrophic signaling plays an important role in neuronal development, neural circuit formation, and neuronal plasticity, but its evolutionary origin remains obscure. We found and validated nucleotide sequences encoding putative neurotrophic ligands (neurotrophin, NT) and receptors (Trk and p75) in two annelids,Platynereis dumerilii(Errantia) andCapitella teleta(Sedentaria, for which some sequences were found recently by Wilson, 2009). Predicted protein sequences and structures ofPlatynereisneurotrophic molecules reveal a high degree of conservation with the vertebrate counterparts; some amino acids signatures present in the annelid Trk sequences are absent in the basal chordate amphioxus, reflecting secondary loss in the cephalochordate lineage. In addition, expression analysis of NT, Trk, and p75 duringPlatynereisdevelopment by whole-mount mRNAin situhybridization supports a role of these molecules in nervous system and circuit development. These annelid data corroborate the hypothesis that the neurotrophic signaling and its involvement in shaping neural networks predate the protostome-deuterostome split and were present in bilaterian ancestors.


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