Skeletal muscle transformation into electric organ ins. macrurus depends on innervation

2002 ◽  
Vol 53 (3) ◽  
pp. 391-402 ◽  
Author(s):  
Graciela A. Unguez ◽  
Harold H. Zakon
Keyword(s):  
Skeletal Muscle ◽  
Electric Organ ◽  
Muscle Transformation

scholarly journals Eel electric organ: hyperexpressing calmodulin system.

1986 ◽  
Vol 6 (3) ◽  
pp. 950-954 ◽  
Author(s):  
R P Munjaal ◽  
C G Connor ◽  
R Turner ◽  
J R Dedman
Keyword(s):  
Skeletal Muscle ◽  
Calcium Binding ◽  
Genome Rearrangement ◽  
Electric Organ ◽  
Functional Expression ◽  
Cellular Regulation ◽  
Calmodulin Binding ◽  
Electrophorus Electricus ◽  
Gene Copies ◽  
Electric Eel

The electroplax of the electric eel Electrophorus electricus is the most abundant source of the calcium-binding protein calmodulin. The electroplax has 250 times the amount of calmodulin and its mRNA than eel skeletal muscle. Our data suggest that there is no major difference in gene copies, the degree of methylation, or genome rearrangement of the calmodulin gene in DNAs from eel electroplax and muscle. Differences in the calmodulin-binding proteins in electroplax and muscle suggest a differential role for the functional expression of calmodulin in cellular regulation.

Positive Modulators of Acetylcholine Receptor: Differences Between Skeletal Muscle and Electric Organ

1989 ◽  
pp. 565-584
Author(s):  
Vesna A. Eterovic ◽  
Richard M. Hann ◽  
P. A. Ferchmin ◽  
Gladys Escalona de Motta ◽  
Jose del Castillo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Acetylcholine Receptor ◽  
Electric Organ

scholarly journals The myogenic electric organ ofSternopygus macrurus: a non-contractile tissue with a skeletal muscle transcriptome

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1828 ◽  
Author(s):  
Matthew Pinch ◽  
Robert Güth ◽  
Manoj P. Samanta ◽  
Alexander Chaidez ◽  
Graciela A. Unguez
Keyword(s):  
Skeletal Muscle ◽  
Striated Muscle ◽  
Electric Organ ◽  
Cell Types ◽  
Sarcomeric Proteins ◽  
Muscle Properties ◽  
Functional Studies ◽  
Myogenic Program ◽  
Contractile Tissue ◽  
Skeletal Muscle Transcriptome

In most electric fish species, the electric organ (EO) derives from striated muscle cells that suppress many muscle properties. In the gymnotiformSternopygus macrurus, mature electrocytes, the current-producing cells of the EO, do not contain sarcomeres, yet they continue to make some cytoskeletal and sarcomeric proteins and the muscle transcription factors (MTFs) that induce their expression. In order to more comprehensively examine the transcriptional regulation of genes associated with the formation and maintenance of the contractile sarcomere complex, results from expression analysis using qRT-PCR were informed by deep RNA sequencing of transcriptomes and miRNA compositions of muscle and EO tissues from adultS. macrurus. Our data show that: (1) components associated with the homeostasis of the sarcomere and sarcomere-sarcolemma linkage were transcribed in EO at levels similar to those in muscle; (2) MTF families associated with activation of the skeletal muscle program were not differentially expressed between these tissues; and (3) a set of microRNAs that are implicated in regulation of the muscle phenotype are enriched in EO. These data support the development of a unique and highly specialized non-contractile electrogenic cell that emerges from a striated phenotype and further differentiates with little modification in its transcript composition. This comprehensive analysis of parallel mRNA and miRNA profiles is not only a foundation for functional studies aimed at identifying mechanisms underlying the transcription-independent myogenic program inS. macrurusEO, but also has important implications to many vertebrate cell types that independently activate or suppress specific features of the skeletal muscle program.

Eel electric organ: hyperexpressing calmodulin system

1986 ◽  
Vol 6 (3) ◽  
pp. 950-954
Author(s):  
R P Munjaal ◽  
C G Connor ◽  
R Turner ◽  
J R Dedman
Keyword(s):  
Skeletal Muscle ◽  
Calcium Binding ◽  
Genome Rearrangement ◽  
Electric Organ ◽  
Functional Expression ◽  
Cellular Regulation ◽  
Calmodulin Binding ◽  
Electrophorus Electricus ◽  
Gene Copies ◽  
Electric Eel

The electroplax of the electric eel Electrophorus electricus is the most abundant source of the calcium-binding protein calmodulin. The electroplax has 250 times the amount of calmodulin and its mRNA than eel skeletal muscle. Our data suggest that there is no major difference in gene copies, the degree of methylation, or genome rearrangement of the calmodulin gene in DNAs from eel electroplax and muscle. Differences in the calmodulin-binding proteins in electroplax and muscle suggest a differential role for the functional expression of calmodulin in cellular regulation.

scholarly journals A novel 87,000-Mr protein associated with acetylcholine receptors in Torpedo electric organ and vertebrate skeletal muscle.

1989 ◽  
Vol 109 (4) ◽  
pp. 1753-1764 ◽  
Author(s):  
C Carr ◽  
G D Fischbach ◽  
J B Cohen
Keyword(s):  
Skeletal Muscle ◽  
Acetylcholine Receptors ◽  
Large Fraction ◽  
Surface Membrane ◽  
Electric Organ ◽  
Postsynaptic Membrane ◽  
Velocity Sedimentation ◽  
Synaptic Membranes ◽  
Torpedo Electric Organ

To identify proteins associated with nicotinic postsynaptic membranes, mAbs have been prepared to proteins extracted by alkaline pH or lithium diiodosalicylate from acetylcholine receptor-rich (AChR) membranes of Torpedo electric organ. Antibodies were obtained that recognized two novel proteins of 87,000 Mr and a 210,000:220,000 doublet as well as previously described proteins of 43,000 Mr, 58,000 (51,000 in our gel system), 270,000, and 37,000 (calelectrin). The 87-kD protein copurified with acetylcholine receptors and with 43- and 51-kD proteins during equilibrium centrifugation on continuous sucrose gradients, whereas a large fraction of the 210/220-kD protein was separated from AChRs. The 87-kD protein remained associated with receptors and 43-kD protein during velocity sedimentation through shallow sucrose gradients, a procedure that separated a significant amount of 51-kD protein from AChRs. The 87- and 270-kD proteins were cleaved by Ca++-activated proteases present in crude preparations and also in highly purified postsynaptic membranes. With the exception of anti-37-kD antibodies, some of the monoclonals raised against Torpedo proteins also recognized determinants in frozen sections of chick and/or rat skeletal muscle fibers and in permeabilized chick myotubes grown in vitro. Anti-87-kD sites were concentrated at chick and rat endplates, but the antibodies also recognized determinants present at lower site density in the extrasynaptic membrane. Anti-210:220-kD labeled chick endplates, but studies of neuron-myotube cocultures showed that this antigen was located on neurites rather than the postsynaptic membrane. As reported in other species, 43-kD determinants were restricted to chick endplates and anti-51-kD and anti-270-kD labeled extrasynaptic as well as synaptic membranes. None of the cross reacting antibodies recognized determinants on intact (unpermeabilized) myotubes, so the antigens must be located on the cytoplasmic aspect of the surface membrane. The role that each intracellular determinant plays in AChR immobilization at developing and mature endplates remains to be investigated.

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