Professor Karl Swann

Head of Biomedicine Division

School of Biosciences

: SwannK1@cardiff.ac.uk
: +44 29208 79009
: Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX

: Available for postgraduate supervision

I am interested in cell signalling and metabolism during animal fertilization and early embryo development. I use live cell imaging methods including those based on fluorescence and chemiluminescence.

Selected projects are:

1. The role and mechanism of action of PLCzeta in causing Ca²⁺ oscillation in eggs at fertilization

2. The relationship between Ca²⁺ and mitochondrial ATP production in eggs

Roles

Head of Biomedicine Division
Deputy Module Leader and teaching on BI2331 Physiology
Teaching on BI2231 Cell Biology
Supervision of projects for Final Year Undergraduate and Masters students

2023

-Eshalomi, C., Aliyev, E., Hoehn, S., Jurkowski, T. P. and Swann, K. 2023. Sperm induce a secondary increase in ATP levels in mouse eggs that is independent of Ca2+ oscillations. Biochemical Journal 480(24), pp. 2023-2035. (10.1042/bcj20230065)
Swann, K. 2023. Sperm-induced Ca2+ release in mammalian eggs: The roles of PLCζ, InsP3, and ATP. Cells 12(24), article number: 2809. (10.3390/cells12242809)
Biolková, M. et al. 2023. Investigation of potential gender bias in the peer review system at Reproduction. Learned Publishing 36(1), pp. 25-30. (10.1002/leap.1537)

2022

Swann, K. 2022. PLCzeta as the sperm factor that activates eggs: 20 years on. Reproduction 164(1), pp. E1-E4. (10.1530/REP-22-0148)
Thanassoulas, A., Swann, K., Lai, F. A. and Nomikos, M. 2022. Sperm factors and egg activation: the structure and function relationship of sperm plcz1. Reproduction 164(1), pp. F1-F8. (10.1530/REP-21-0477)
Wang, Y., Pope, I., Brennan-Craddock, H., Poole, E., Langbein, W., Borri, P. and Swann, K. 2022. A primary effect of palmitic acid on mouse oocytes is the disruption of the structure of the endoplasmic reticulum. Reproduction 163(1), pp. 45-56. (10.1530/REP-21-0332)

2021

Ostler, T. et al. 2021. Vitrifying multiple embryos in different arrangements does not alter the cooling rate. Cryobiology 103, pp. 22-31. (10.1016/j.cryobiol.2021.10.001)
Graham, C. F. et al. 2021. Dynamic shapes of the zygote and two-cell mouse and human. Biology Open 10(12), article number: bio059013. (10.1242/bio.059013)
Pope, I. et al. 2021. Background-free 3D four-wave mixing microscopy of single gold nanoparticles inside biological systems. Presented at: European Conference on Biomedical Optics 2021, Munich, Germany, 20-24 June 2021European Conferences on Biomedical Optics 2021 (ECBO). OSA Technical Digest Optical Society of America pp. EM3B.6.
Storey, A., Elgmati, K., Wang, Y., Knaggs, P. and Swann, K. 2021. The role of ATP in the differential ability of Sr2+ to trigger Ca2+ oscillations in mouse and human eggs. Molecular Human Reproduction 27(1), article number: gaaa086. (10.1093/molehr/gaaa086)

2020

Swann, K. 2020. The soluble sperm factor that activates the egg: PLCzeta and beyond. Reproduction 160(1) (10.1530/REP-20-0079)

2019

Bradley, J., Pope, I., Wang, Y., Langbein, W., Borri, P. and Swann, K. 2019. Dynamic label-free imaging of lipid droplets and their link to fatty acid and pyruvate oxidation in mouse eggs. Journal of Cell Science 132(13), article number: jcs228999. (10.1242/jcs.228999)
Bradley, J. and Swann, K. 2019. Mitochondria and lipid metabolism in mammalian oocytes and early embryos. International Journal of Developmental Biology 63(3-4-5), pp. 93-103. (10.1387/ijdb.180355ks)
Borri, P., Bradley, J., Pope, I., Langbein, W. and Swann, K. 2019. Imaging lipids in living mammalian oocytes and early embryos by coherent Raman scattering microscopy. Presented at: SPIE BIOS, San Francisco, CA, USA, 2-7 February 2019Proceedings Volume 10890, Label-free Biomedical Imaging and Sensing (LBIS) 2019, Vol. 108900. Society of Photo-Optical Instrumentation Engineers (SPIE) pp. 3., (10.1117/12.2506248)

2018

Swann, K. 2018. The role of Ca 2+ in oocyte activation during In Vitro fertilization: Insights into potential therapies for rescuing failed fertilization. BBA - Molecular Cell Research 1865(11), pp. 1830-1837. (10.1016/j.bbamcr.2018.05.003)
Pope, I. et al. 2018. Coherent Raman Scattering microscopy: technology developments and biological applications. Presented at: 20th International Conference on Transparent Optical Networks (ICTON), Bucharest, Romania, 1-5 Jul 201820th International Conference on Transparent Optical Networks (ICTON). IEEE, (10.1109/ICTON.2018.8473706)
FitzHarris, G., Carroll, J. and Swann, K. 2018. Electrical-assisted microinjection for analysis of fertilization and cell division in mammalian oocytes and early embryos. Methods in Cell Biology 144, pp. 431-440. (10.1016/bs.mcb.2018.03.036)
Sanders, J., Ashley, B., Moon, A., Woolley, T. and Swann, K. 2018. PLCz induced Ca2+ oscillations in mouse eggs involve a positive feedback cycle of Ca2+ induced InsP3 formation from cytoplasmic PIP2. Frontiers in Cell and Developmental Biology 6, article number: 36. (10.3389/fcell.2018.00036)

2017

Nomikos, M., Swann, K. and Lai, F. A. 2017. Fundamental role for sperm phospholipase C ζ in mammalian fertilization. In: De Jonge, C. J. and Barratt, C. L. R. eds. The Sperm Cell. Cambridge: Cambridge University Press, pp. 177-192., (10.1017/9781316411124.014)
Nomikos, M. et al. 2017. Male infertility-linked point mutation reveals a vital binding role for the C2 domain of sperm PLCζ. Biochemical Journal 474(6), pp. 1003-1016. (10.1042/BCJ20161057)
Kashir, J. et al. 2017. Antigen unmasking enhances visualization efficacy of the oocyte activation factor, phospholipase C zeta, in mammalian sperm. Molecular Human Reproduction 23(1), pp. 54-67. (10.1093/molehr/gaw073)

2016

Sanders, J. R. and Swann, K. 2016. Molecular triggers of egg activation at fertilization in mammals. Reproduction 152(2), article number: R41. (10.1530/REP-16-0123)
Bradley, J., Pope, I., Masia, F., Sanusi, R., Langbein, W., Swann, K. and Borri, P. 2016. Quantitative imaging of lipids in live mouse oocytes and early embryos using CARS microscopy. Development 143, pp. 2238-2247. (10.1242/dev.129908)
Swann, K. and Lai, F. A. 2016. The sperm phospholipase C-ζ and Ca2+ signalling at fertilization in mammals. Biochemical Society Transactions 44(1), pp. 267-272. (10.1042/BST20150221)
Haverfield, J. et al. 2016. Ca2+ dynamics in oocytes from naturally-aged mice. Scientific Reports 6, article number: 19357. (10.1038/srep19357)
Swann, K. and Lai, F. A. 2016. Egg activation at fertilization by a soluble sperm protein. Physiological Reviews 96(1), pp. 127-149. (10.1152/physrev.00012.2015)

2009

Dumollard, R., Carroll, J., Duchen, M. R., Campbell, K. and Swann, K. 2009. Mitochondrial function and redox state in mammalian embryos. Seminars in Cell and Developmental Biology 20(3), pp. 346-353. (10.1016/j.semcdb.2008.12.013)

2008

Ajduk, A. M., Ciemerych, M. A., Nixon, V., Swann, K. and Maleszewski, M. 2008. Fertilization differently affects the levels of cyclin B1 and M-phase promoting factor activity in maturing and metaphase II mouse oocytes. Reproduction 136(6), pp. 741-752. (10.1530/REP-08-0271)
Yu, Y., Halet, G., Lai, F. A. and Swann, K. 2008. Regulation of diacylglycerol production and protein kinase C stimulation during sperm- and PLCζ-mediated mouse egg activation. Biology of the Cell 100(11), pp. 633-643. (10.1042/BC20080033)
Dumollard, R., Campbell, K., Halet, G., Carroll, J. and Swann, K. 2008. Regulation of cytosolic and mitochondrial ATP levels in mouse eggs and zygotes. Developmental Biology 316(2), pp. 431-440. (10.1016/j.ydbio.2008.02.004)
Yu, Y., Saunders, C. M., Lai, F. A. and Swann, K. 2008. Preimplantation development of mouse oocytes activated by different levels of human phospholipase C zeta. Human Reproduction 23(2), pp. 365-373. (10.1093/humrep/dem350)

2006

Campbell, K. and Swann, K. 2006. Ca2+ oscillations stimulate an ATP increase during fertilization of mouse eggs. Developmental Biology 298(1), pp. 225-233. (10.1016/j.ydbio.2006.06.032)

2005

Nomikos, M. et al. 2005. Role of phospholipase C-zeta domains in Ca2+-dependent phosphatidylinositol 4,5-bisphosphate hydrolysis and cytoplasmic Ca2+ oscillations. Journal of biological chemistry 280(35), pp. 31011-31018. (10.1074/jbc.M500629200)

2004

Rogers, N. T., Hobson, E., Pickering, S., Lai, F. A., Braude, P. and Swann, K. 2004. Phospholipase Cζ causes Ca2+ oscillations and parthenogenetic activation of human oocytes. Reproduction 128(6), pp. 697-702. (10.1530/rep.1.00484)
Larman, M. G., Saunders, C. M., Carroll, J., Lai, F. A. and Swann, K. 2004. Cell cycle-dependent Ca2+ oscillations in mouse embryos are regulated by nuclear targeting of PLCzeta. Journal of cell science 117(12), pp. 2513-2521. (10.1242/jcs.01109)

2002

Saunders, C. M. et al. 2002. PLC zeta: a sperm-specific trigger of Ca(2+) oscillations in eggs and embryo development. Development 129(15), pp. 3533-3544.

A major theme in my research is to answer the fundamental question of how the sperm activates the egg at fertilization. At fertilization in all mammals the sperm initiates development by causing a series of oscillations in the cytosolic Ca²⁺ concentration. We have previously shown that the sperm initiates Ca²⁺ oscillations in egg by introducing the sperm specific phospholipase C zeta (PLCzeta) after gamete membrane fusion. PLCzeta generates cycles of InsP₃ production and Ca²⁺ release. We have shown that PLCzeta is unique amongst mammalian PLCs in causing Ca²⁺ oscillations in eggs, and in that it specifically targets intracellular vesicles containing phosphoinositides. Recent studies in mice suggest that there may be an additional factor that promotes Ca²⁺ oscillations in eggs and we have begun to investigate the nature of a putative second sperm factor.

We are currently investigating exactly how PLCzeta causes Ca²⁺ release and what factors in the egg effect the sensitivity to PLCzeta. We study egg activation in mouse eggs and collaborate with the Wales Fertility Institute to study Ca²⁺ oscillations in human eggs. I collaborate with Thomas Woolley and Katerina Kaouri in the School of Mathematics in Cardiff University to model the mechanisms of Ca²⁺ oscillations. I also collaborate with Paola Borri and Wolfgang Langbein (Physics, Cardiff University) and use CARS imaging of eggs and embryos to monitor changes in the endoplasmic reticulum and lipid droplets caused by exposure to fatty acids. We are also investigating the nature of cytoplasmic movements in eggs and early embryos.

I am also interested in the regulation of mitochondrial activity in eggs and early embryos. We are studying the way the sperm stimulates mitochondrial ATP production at fertilization, and how ATP influences Ca²⁺ release. The main aims of these projects is to establish methods for improving egg activation at fertilization and subsequent embryo development.

Current Lab Members

Cindy Ikie (PhD student)

Elnur Aliyev (PhD student)

Zizhen Huang (PhD student)

Maryam Al Shaikh (PhD student)

Collaborators

Prof Paola Borri - Cardiff University

Thomas Woolley - Cardiff University

Dr Paul Knaggs - Wales Fertility Institute

Dr Tomasz Jurkowski – Cardiff University

I am involved in delivering teaching to Year 2, Masters and PhD students. I am also a tutor for Year 2, Year 3 and PTY students.

My Undergraduate teaching involves contributions to modules:

BI2331: Physiology (Deputy Module Lead)

BI2231: Cell Biology

BI2233: Developmental and Stem Cell Biology

BI3001: Biosciences Final Year Project

I completed my BSc Degree and the PhD in the Physiology Department at UCL under the supervision of Michael Whitaker. I worked as a postdoc in Japan with Shun-ichi Miyazaki studying Ca²⁺ oscillations at fertilization in eggs and returned to London to work with David Whittingham at St George’s Hospital Medical School. In 1994 I was appointed as a lecturer in the Department of Anatomy and Developmental Biology at UCL. Then in 2004 I was appointed as the Chair of Reproductive Cell Biology in the School of Medicine at Cardiff University. In 2016 I moved to the School of Biosciences. I hold an HFEA Research Licence to study human egg activation and I am an Editorial Board Member of the journal ‘Reproduction’. I have presented my research at many international meetings including invited talks at five Gordon Research Conferences.

In the 1990s I first described the existence of a soluble sperm protein that could trigger Ca²⁺ oscillations in mammalian eggs. I pioneered the theory that the sperm activates the egg by introducing a soluble sperm protein after gamete fusion. This mechanism of egg activation is now widely recognized as the way the sperm causes egg activation and initiates development. Work in my lab first showed that the principal mammalian sperm factor is a phospholipase C (PLC). Then in collaboration with Tony Lai at Cardiff University I helped demonstrate that the factor is a PLCzeta. I continue to work on egg activation and aspects of mitochondrial metabolism in mammalian eggs.

I am available for supervising Master’s and PhD projects within the general areas of:

1. Ca2+ oscillations and egg activation at fertilization.

2. The role of mitochondria in fertilization and early development.

Current supervision

Cindy Ikie

Research student

Zizhen Huang

Research student

Maryam Eissa H Al Shaikh

Research student

Doctoral student to present research to MPs in Westminster

20 February 2023

Exploring how fats affect eggs and embryo development

10 January 2017

External profiles

ORCID