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Detection of the nicotinic acetylcholine receptor alpha‐subunit mRNA by in situ hybridization at neuromuscular junctions of 15‐day‐old chick striated muscles.
Author(s) -
Fontaine B.,
Sassoon D.,
Buckingham M.,
Changeux J. P.
Publication year - 1988
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1988.tb02853.x
Subject(s) - acetylcholine receptor , in situ hybridization , biology , neuromuscular junction , nicotinic acetylcholine receptor , denervation , acetylcholinesterase , nicotinic agonist , postsynaptic potential , acetylcholine , messenger rna , protein subunit , alpha (finance) , microbiology and biotechnology , anatomy , receptor , endocrinology , biochemistry , neuroscience , gene , enzyme , medicine , construct validity , nursing , patient satisfaction
In adult vertebrate striated muscle, the nicotinic acetylcholine receptor (AChR) is almost exclusively localized in the postsynaptic membrane of the neuromuscular junction. Using in situ hybridization, we show that, in two different chicken muscles [the slow multi‐innervated anterior latissimus dorsi (ALD) and the fast singly innervated posterior latissimus dorsi (PLD)], the AChR alpha‐subunit mRNA is detected at discrete regions on myofibres and that these regions co‐localize (80% correspondence) with neuromuscular junctions identified by histochemical staining for acetylcholinesterase. Moreover, autoradiographic grains densely accumulate on and around subsynaptic nuclei. In contrast, hybridization with an actin probe results in a strong signal distributed over the entire length of the myofibres. Denervation increases the level of AChR alpha‐subunit mRNA both in the PLD and to a lesser extent in the ALD. By in situ hybridization we observe that, although a perinuclear pattern is maintained, the labelled nuclei appear randomly distributed among approximately 10% of the nuclei. These results are discussed in a model of AChR gene expression in vertebrate striated muscle fibres.