Characterization of the sperm-induced calcium wave in Xenopus eggs using confocal microscopy.
AuthorsFontanilla RA, Nuccitelli R
JournalBiophys J
PubMed ID9746550
'We have used confocal microscopy to examine the [Ca2+]i increase in the albino eggs of the frog Xenopus laevis after fertilization. Eggs were placed in agar wells with their animal poles downward so that fertilization occurred preferentially in the equatorial plane, and confocal microscopy was used to provide a two-dimensional ... More
Abscisic acid signal transduction in guard cells is mediated by phospholipase D activity.
AuthorsJacob T, Ritchie S, Assmann SM, Gilroy S
JournalProc Natl Acad Sci U S A
PubMed ID10518598
'In guard cells, the plant hormone abscisic acid (ABA) inhibits stomatal opening and induces stomatal closure through the coordinated regulation of ion transport. Despite this central role of ABA in regulating stomatal function, the signal transduction events leading to altered ion fluxes remain incompletely understood. We report that the activity ... More
Cytoplasmic free Ca2+ in Arabidopsis roots changes in response to touch but not gravity.
AuthorsLegué V, Blancaflor E, Wymer C, Perbal G, Fantin D, Gilroy S
JournalPlant Physiol
PubMed ID9232870
'Changes in cytoplasmic Ca2+ concentration ([Ca2+]i) have been proposed to be involved in signal transduction pathways in response to a number of stimuli, including gravity and touch. The current hypothesis proposes that the development of gravitropic bending is correlated with a redistribution of [Ca2+]i in gravistimulated roots. However, no study ... More
The passage of Ca2+ and fluorescent markers between the sperm and egg after fusion in the mouse.
AuthorsJones KT, Soeller C, Cannell MB
JournalDevelopment
PubMed ID9806912
'Mouse sperm-egg fusion was examined using two-photon and confocal microscopy. A delay of several minutes occurred between the first observable event of fusion (which was the diffusion of Ca2+-sensitive dyes from egg into sperm) and any change in egg cytoplasmic Ca2+. When indo-1 dextran was used to obtain ratiometric two-photon ... More
The calcium feedback signal in the phototransduction cascade of vertebrate rods.
AuthorsGray-Keller MP, Detwiler PB
JournalNeuron
PubMed ID7524559
'Intracellular free Ca (Cai) was measured in functionally intact rod outer segments in darkness and during light responses using the fluorescent Ca indicator Indo-dextran. In darkness, Cai was 554 +/- 25 nM (n = 28) for -85 +/- 2 pA of circulating dark current (Id) and declined in saturating light ... More
Practical aspects of measuring [Ca2+] with fluorescent indicators.
AuthorsKao JP
JournalMethods Cell Biol
PubMed ID8201975
Ca2+ dependence of dark- and light-adapted flash responses in rod photoreceptors.
AuthorsGray-Keller MP, Detwiler PB
JournalNeuron
PubMed ID8780655
Light adaptation is thought to be orchestrated by a Ca2+ feedback signal that desensitizes the response by speeding recovery. To evaluate the role of Ca2+ in adaptation, we compared the effect of lowered Ca2+ on response properties in darkness and during adaptation. Internal Ca2+ was reduced from its normal resting ... More
Ca2+ oscillations in plant cells: initiation by rapid elevation in cytosolic free Ca2+ levels.
AuthorsCalder GM, Franklin-Tong VE, Shaw PJ, Drøbak BK
JournalBiochem Biophys Res Commun
PubMed ID9175777
Temporal increases in intracellular [Ca2+] are now recognized to be key triggers for a wide range of important physiological events in eukaryotic cells. In mammalian cells, signal-induced Ca2+-elevations have been found to be of a pulsatile nature and Ca2+ spikes display a high degree of spatiotemporal complexity. In plant cells ... More
ATP-dependent regulation of nuclear Ca(2+) levels in plant cells.
AuthorsBunney TD, Shaw PJ, Watkins PA, Taylor JP, Beven AF, Wells B, Calder GM, Drøbak BK
JournalFEBS Lett
PubMed ID10913602
Localised alterations in cytoplasmic Ca(2+) levels are an integral part of the response of eukaryotic cells to a plethora of external stimuli. Due to the large size of nuclear pores, it has generally been assumed that intranuclear Ca(2+) levels reflect the prevailing cytoplasmic Ca(2+) levels. Using nuclei prepared from carrot ... More