Linked Life Data

8253277

Source:http://linkedlifedata.com/resource/pubmed/id/8253277

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-1-7
pubmed:abstractText
In order to evaluate the effects of specific mutations on sarcomere assembly and function in vivo, we describe the course of normal development of Drosophila indirect flight muscle (IFM) in staged pupae using electron microscopy. We find that no contractile assemblies remain in larval muscle remnants invaded by imaginal myoblasts, establishing that myofibrils in IFM assemble de novo. Stress-fiber-like structures or other template structures are not prominent before or during sarcomere assembly. By 42 hr pupation (eclosion approximately 112 hr), thick and thin filaments have appeared simultaneously in slender, interdigitated arrays between regularly spaced Z-bodies. Each tiny, uniformly striated myofibril forms within a "sleeve" of microtubules, and both microtubules and myofibrils are attached to the cell membrane at each end of the fiber from the initial stages of assembly. Later in pupation, the microtubule "sleeves" disassemble. Sarcomere number appears to remain constant. We saw no evidence that terminal sarcomeres are sites for addition of new sarcomeres or that Z-lines split transversely, producing new, very short sarcomeres. Rather, initial thick and thin filaments and sarcomeres are much shorter than adult length. Sarcomere length increases smoothly and coordinately from approximately 1.7 to approximately 3.2 microns, reflecting increase in filament lengths and indicating that myosin and actin molecules must be incorporated into filaments after sarcomere formation. Myofilaments are not seen scattered in the cytoplasm at any time, nor do we detect filaments that could be in the process of being "trolleyed" along myofibrils into positions of lateral register. Myofibril diameter increases uniformly from approximately 4-thick filaments to approximately 36-thick filaments across, by peripheral addition of myofilaments. At each successive stage, all sarcomeres in a fiber attained similar length and diameter. Initial thick filaments are solid but within several hours these and all subsequently assembled thick filaments appear hollow. Initial Z-bodies do not show any internal lattice and are more irregularly shaped than adult Z-discs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0012-1606
pubmed:author
pubmed:issnType
Print
pubmed:volume
160
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
443-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Ultrastructure of developing flight muscle in Drosophila. I. Assembly of myofibrils.
pubmed:affiliation
Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't