Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-10-12
pubmed:abstractText
Sea bass spermatozoa are maintained immotile in the seminal fluid, but initiate swimming for 45 s at 20 degrees C, immediately after dispersion in a hyperosmotic medium (1100 mOsm kg-1). The duration of this motile period could be extended by a reduction of the amplitude of the hyperosmotic shock. Five seconds after the initiation of motility, 94.4 +/- 1.8% of spermatozoa were motile with a swimming velocity of 141.8 +/- 1.2 microns s-1, a flagellar beat frequency of 60 Hz and a symmetric type of flagellar swimming, resulting in linear tracks. Velocity, flagellar beat frequency, percentage of motile cells and trajectory diameter decreased concomitantly throughout the swimming phase. After 30 s of motility, the flagellar beat became asymmetric, leading to circular trajectories. Ca2+ modulated the swimming pattern of demembranated spermatozoa, suggesting that the asymmetric waves produced by intact spermatozoa after 30 s of motility were induced by an accumulation of intracellular Ca2+. Moreover, increased ionic strength in the reactivation medium induced a dampening of waves in the distal portion of the flagellum and, at high values, resulted in an arrest of wave generation in demembranated spermatozoa. In non-demembranated cells, the intracellular ATP concentration fell immediately after transfer to sea water. In contrast, the AMP content increased during the same period, while the ADP content increased slightly. In addition, several morphological changes affected the mitochondria, chromatin and midpiece. These results indicate that the short swimming period of sea bass spermatozoa is controlled by energetic and cytoplasmic ionic conditions and that it is limited by osmotic stress, which induces marked changes in cell morphology.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-4251
pubmed:author
pubmed:issnType
Print
pubmed:volume
116
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
113-25
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Effects of osmolality, morphology perturbations and intracellular nucleotide content during the movement of sea bass (Dicentrarchus labrax) spermatozoa.
pubmed:affiliation
MNHN, Laboratoire d'Ichtyologie, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't