TY - JOUR
T1 - Xenopus tropicalis oocytes as an advantageous model system for the study of intracellular Ca2+ signalling
AU - Marchant, J. S.
AU - Parker, I.
PY - 2001
Y1 - 2001
N2 - 1. The purpose of this study was to compare oocytes from the pipid frogs Xenopus tropicalis and Xenopus laevis, with respect to their utility for studying Ca2+ signalling mechanisms and for expression of heterologous proteins. 2. We show that X. tropicalis oocytes possess an intracellular Ca2+ store that is mobilized by inositol (1,4,5) trisphosphate (IP3). Ca2+ signalling is activated by endogenous lysophosphatidic acid receptors and cytosolic Ca2+ activates a plasma membrane chloride conductance. The spatiotemporal organization of cytosolic Ca2+ signals, from the microscopic architecture of elementary Ca2+ 'puffs' to the macroscopic patterns of Ca2+ spiking are closely similar to the local and global patterns of Ca2+ release previously characterized in oocytes from X. laevis. 3. By injecting X. tropicalis oocytes with cDNA encoding an ER-targeted fluorescent protein construct, we demonstrate the capacity of the X. tropicalis oocyte to readily express heterologous proteins. The organization of ER is polarized across the oocyte, with the IP3-releaseable store targeted within an ∼8 μm wide band that circumscribes the cell. 4. We conclude that the X. tropicalis oocyte shares many of the characteristics that have made oocytes of X. laevis a favoured system for studying Ca2+ signalling mechanisms. Moreover, X. tropicalis oocytes display further practical advantages in terms of imaging depth, Ca2+ signal magnitude and electrical properties. These further enhance the appeal of X. tropicalis as an experimental system, in addition to its greater amenability to transgenic approaches.
AB - 1. The purpose of this study was to compare oocytes from the pipid frogs Xenopus tropicalis and Xenopus laevis, with respect to their utility for studying Ca2+ signalling mechanisms and for expression of heterologous proteins. 2. We show that X. tropicalis oocytes possess an intracellular Ca2+ store that is mobilized by inositol (1,4,5) trisphosphate (IP3). Ca2+ signalling is activated by endogenous lysophosphatidic acid receptors and cytosolic Ca2+ activates a plasma membrane chloride conductance. The spatiotemporal organization of cytosolic Ca2+ signals, from the microscopic architecture of elementary Ca2+ 'puffs' to the macroscopic patterns of Ca2+ spiking are closely similar to the local and global patterns of Ca2+ release previously characterized in oocytes from X. laevis. 3. By injecting X. tropicalis oocytes with cDNA encoding an ER-targeted fluorescent protein construct, we demonstrate the capacity of the X. tropicalis oocyte to readily express heterologous proteins. The organization of ER is polarized across the oocyte, with the IP3-releaseable store targeted within an ∼8 μm wide band that circumscribes the cell. 4. We conclude that the X. tropicalis oocyte shares many of the characteristics that have made oocytes of X. laevis a favoured system for studying Ca2+ signalling mechanisms. Moreover, X. tropicalis oocytes display further practical advantages in terms of imaging depth, Ca2+ signal magnitude and electrical properties. These further enhance the appeal of X. tropicalis as an experimental system, in addition to its greater amenability to transgenic approaches.
KW - Endoplasmic reticulum
KW - Inositol 1,4,5 trisphosphate
KW - Oocyte
KW - Xenopus
UR - http://www.scopus.com/inward/record.url?scp=0035069688&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035069688&partnerID=8YFLogxK
U2 - 10.1038/sj.bjp.0703922
DO - 10.1038/sj.bjp.0703922
M3 - Article
C2 - 11264232
AN - SCOPUS:0035069688
SN - 0007-1188
VL - 132
SP - 1396
EP - 1410
JO - British Journal of Pharmacology
JF - British Journal of Pharmacology
IS - 7
ER -