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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
3
|
| pubmed:dateCreated |
1977-4-15
|
| pubmed:abstractText |
Waves of chemotactic movement during the early phase of aggregation in Dictyostelium discoideum are of 2 kinds, concentric waves produced by cells that emit cyclic AMP signals spontaneously, and spirals generated by excitations relayed continuously around loops of excitable cells. The period of a spiral wave is the time taken for the excitation to make one complete circuit of the pacemaker loop. We have compared signal emission from the 2 types of source in time-lapse films made at a variety of temperatures. Our results show that spiral waves have a characteristic period length throughout most if not all of the early phase of aggregation, and that the period of concentric waves is generally longer and more variable. Temperature has a pronounced effect on period length and a lesser effect on propagation velocity. We find that each individual wave is propagated at constant velocity over distances of 1-2 cm but that the velocity of successive waves declines. This decline probably reflects some cumulative effect of the chemotactic excitations on the excitable properties of the aggregating cells.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Dec
|
| pubmed:issn |
0021-9533
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
22
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
645-56
|
| pubmed:dateRevised |
2000-12-18
|
| pubmed:meshHeading | |
| pubmed:year |
1976
|
| pubmed:articleTitle |
Signal emission and signal propagation during early aggregation in Dictyostelium discoideum.
|
| pubmed:publicationType |
Journal Article
|