Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-3-1
pubmed:abstractText
The lumbosacral spinal cords of 14.5-day gestation mice (E14.5) were ablated. The number of molecules of each of the four myogenic regulatory factor (MRF) mRNAs per nanogram of total RNA were evaluated in innervated and aneural fetal crural muscles. Accumulation of all four MRF mRNAs was affected in aneural muscle, but was never more than threefold different than in innervated muscles, considerably less than after adult denervation. The effect of the nerve varied with the MRF, the fetal age, and with the muscle (extensor digitorum longus muscle [EDL] vs. soleus muscle), with the nerve having multiple effects including down-regulation of certain MRF genes at specific periods (e.g., myoD and myogenin [E16.5-E18.5] and MRF4 in the EDL only [E18.5-E19.5]); limiting the up-regulation of certain genes, which occurred in the absence of innervation (e.g., myf-5 [E18.5-E19.5] and myogenin [E14.5-E16.5]); and even enhancing the accumulation of MRF4 mRNA (E14.5-E16.5). We hypothesize that factors other than nerve contribute to the down-regulation of myf-5 and myogenin mRNAs to adult levels. Innervation was required for the emergence of the slow, but not the fast, MRF mRNA profile at birth. MyoD, found in both the nuclear and cytoplasmic protein extracts of innervated fetal muscle, increased by approximately 5-fold in the nuclear extracts (approximately 2.5-fold in the cytoplasmic) of E19.5 aneural muscles, significantly less than the 12-fold increase found in the nuclear extract of 4-day denervated adult muscle. This increase in aneural fetal muscle was due primarily to an increased concentration of myoD in muscle lineage nuclei, rather than to the presence of additional myoD(+) muscle lineage nuclei.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1058-8388
pubmed:author
pubmed:issnType
Print
pubmed:volume
236
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
732-45
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Neuronal control of myogenic regulatory factor accumulation in fetal muscle.
pubmed:affiliation
Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural