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Changes in the ribonucleoprotein constituents of the nucleus during the differentiation of muscle cells in the chick embryo
Author(s) -
Zavala Guadalupe,
Aguilar Xochtil,
Jiménez Felipe Luis,
Echeverría Olga M,
VázquezNin Gerardo
Publication year - 1992
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1016/0248-4900(92)90208-i
Subject(s) - biology , myogenesis , microbiology and biotechnology , nucleus , mitosis , myofibril , myocyte , embryo , ribonucleoprotein , anatomy , neuroblast , electron microscope , rna , biochemistry , gene , physics , neurogenesis , optics
Summary— The ribonucleoprotein components of the nucleus of chick embryo muscle cells in different stages of development were studied by electron microscopic quantitative stereology. The changes of the constituents were related with the appearance of the innervation by means of silver impregnation for light microscope. The numerical density of the perichromatin granules (PCG) is low in mononuclear cells and myotubes. It is noteworthy that the frequency of the PCG does not change during the transition of the cells in mitotic cycle to postmitotic myoblasts and during myofibril differentiation. However, there is an important increment in this parameter when the motor nerve fibers arrive at the muscle and the synaptic contacts are established. This change is correlated with appearance, or at least with a great increasé, of the importance of posttranscriptional controls of the expression of some genes. The augmentation in the frequency of PCG is not accompanied by alterations of the abundance of total RNP particles, in close resemblance with the phenomena occurring in neuroblast during the differentiation of synaptic endings. The variations of the nucleolar volume coincide with the changes in rRNA synthesis.