Rhythmic actomyosin-driven contractions induced by sperm entry predict mammalian embryo viability
Abstract
Fertilization-induced cytoplasmic flows are a conserved feature of eggs in many species. However, until now the importance of cytoplasmic flows for the development of mammalian embryos has been unknown. Here, by combining a rapid imaging of the freshly fertilized mouse egg with advanced image analysis based on particle image velocimetry, we show that fertilization induces rhythmical cytoplasmic movements that coincide with pulsations of the protrusion forming above the sperm head. We find that these movements are caused by contractions of the actomyosin cytoskeleton triggered by Ca^(2+) oscillations induced by fertilization. Most importantly, the relationship between the movements and the events of egg activation makes it possible to use the movements alone to predict developmental potential of the zygote. In conclusion, this method offers, thus far, the earliest and fastest, non-invasive way to predict the viability of eggs fertilized in vitro and therefore can potentially improve greatly the prospects for IVF treatment.
Additional Information
© 2011 Macmillan Publishers Limited. This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ Received 18 February 2011. Accepted 07 June 2011. Published 09 August 2011. We thank Drs Melina Schuh for UtrCH–EGFP; Ewa Paluch for MyoRLC–GFP constructs; William Mansfield for his help with embryo transfers; and David Glover, Krzysztof Wicher, Samantha Morris, Kevin Coward and Celine Jones for their advice and support. The work was funded by the Wellcome Trust with grants to M.Z.-G., T.I., K.S. and A.T. A.A. was a recipient of the FEBS Short-Term Fellowship and of 'START' and 'KOLUMB' fellowships from the Foundation for Polish Science. T.I. was supported by the AstraZeneca funding for MB/PhD students. R.J.B. holds an EPSRC Career Acceleration Fellowship and was supported during this work by the BBSRC. K.B.S. was supported by the Oxford MSc Programme in Clinical Embryology. B.D.T. was funded by the UK Medical Research Council under the Programme Grant MC_US_A030_0022. Author Contributions: All the data was collected in M.Z.-G's laboratory and most data in this paper is the result of experiments conducted by A.A., T.I., Y.Y. and K.B.S. with image processing carried out by S.W., R.J.B. and A.A,. and statistical analysis by B.D.T. The other authors provided extensive advice over a long period of collaboration. The paper was written by A.A. and M.Z.-G, with some methodological sections revised by S.W. and B.D.T. Competing interests: A U.S. patent has been filed on this work. 'Methods for predicting mammalian embryo viability' (US application no. 61/503827).Attached Files
Published - ncomms1424.pdf
Supplemental Material - ncomms1424-s1.pdf
Supplemental Material - ncomms1424-s2.mov
Supplemental Material - ncomms1424-s3.mov
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Additional details
- PMCID
- PMC3265380
- Eprint ID
- 94766
- Resolver ID
- CaltechAUTHORS:20190417-163114215
- Wellcome Trust
- Federation of the European Biochemical Societies (FEBS)
- Foundation for Polish Science
- AstraZeneca
- Engineering and Physical Sciences Research Council (EPSRC)
- Biotechnology and Biological Sciences Research Council (BBSRC)
- University of Oxford
- MC_US_A030_0022
- Medical Research Council (UK)
- Created
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2019-04-18Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field