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Updated: May 5, 2026
Yeast Luminometric and Xenopus Oocyte Electrophysiological Examinations of the Molecular Mechanosensitivity of TRPV4
Published on: December 31, 2013
TRPV3 channels mediate strontium-induced mouse-egg activation
Ingrid Carvacho1, Hoi Chang Lee2, Rafael A Fissore2
1Howard Hughes Medical Institute, Department of Cardiology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
Abstract:
In mammals, calcium influx is required for oocyte maturation and egg activation. The molecular identities of the calcium-permeant channels that underlie the initiation of embryonic development are not established. Here, we describe a transient receptor potential (TRP) ion channel current activated by TRP agonists that is absent in TrpV3(-/-) eggs. TRPV3 current is differentially expressed during oocyte maturation, reaching a peak of maximum density and activity at metaphase of meiosis II (MII), the stage of fertilization. Selective activation of TRPV3 channels provokes egg activation by mediating massive calcium entry. Widely used to activate eggs, strontium application is known to yield normal offspring in combination with somatic cell nuclear transfer. We show that TRPV3 is required for strontium influx, because TrpV3(-/-) eggs failed to conduct Sr(2+) or undergo strontium-induced activation. We propose that TRPV3 is a major mediator of calcium influx in mouse eggs and is a putative target for artificial egg activation.
Insights
Transient Receptor Potential Vanilloid 3 (TRPV3) channels mediate calcium influx essential for mammalian egg activation. These TRPV3 channels are crucial for strontium-induced egg activation and embryonic development.
Area of Science:
- Reproductive Biology
- Ion Channel Physiology
- Developmental Biology
Background:
- Calcium influx is critical for mammalian oocyte maturation and egg activation.
- The specific ion channels responsible for this calcium influx remain largely unidentified.
Purpose of the Study:
- To identify the molecular identity of calcium-permeant channels involved in initiating embryonic development.
- To investigate the role of TRPV3 in oocyte maturation, egg activation, and strontium-induced activation.
Main Methods:
- Electrophysiological recordings of ion channel currents in oocytes.
- Analysis of oocyte maturation and activation in wild-type and TrpV3 knockout mouse models.
- Assessment of strontium ion (Sr(2+)) influx and activation in TrpV3(-/-) eggs.
Main Results:
- A novel transient receptor potential (TRP) ion channel current, identified as TRPV3, was characterized.
- TRPV3 expression and activity peak at metaphase of meiosis II (MII), the stage of fertilization.
- TRPV3 activation mediates significant calcium entry, inducing egg activation.
- TrpV3 knockout eggs lack strontium influx and fail to activate in response to strontium.
Conclusions:
- TRPV3 is a key mediator of calcium influx in mouse oocytes.
- TRPV3 is essential for strontium-induced egg activation.
- TRPV3 represents a potential target for artificial egg activation strategies.
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