Anne Carlson

  • Assistant Professor
  • Fertilization & Channels

Contact

201 Life Sciences Annex
4249 Fifth Avenue
Pittsburgh, PA 15260

Polyspermy, the fertilization of an egg by more than one sperm, is a common problem faced by the eggs of all sexually reproducing species and causes severe chromosomal defects and embryonic mortality.  The effects of polyspermy are evident in the development of cleavage furrows shortly after fertilization.

In normal fertilization, the embryonic cleavage furrows develop symmetrically and transverse the entire embryo (center photo at 8 cell stage).  By contrast, the cleavage furrows develop irregularly following fertilization by more than one sperm (right photo) (Wozniak, Mayfield, & Carlson, unpublished).

Our lab strives to uncover the crucial signaling events ensuring that only one sperm enters the egg and thereby allowing for normal embryonic development.  Eggs can possess two mechanisms to prevent more than one sperm from entering at fertilization.  One such mechanism, called the fast block to polyspermy, exists in many species in the form of a prolonged membrane depolarization of the egg.

Fertilization-evoked depolarization in X. laevis eggs (recording by Wozniak, unpublished).  Line denotes 0 mV.

The channels that mediate this depolarization and the signaling pathways that regulate it are unknown.  To uncover the earliest signaling events evoked by fertilization, we use the African clawed frog Xenopus laevis as the model system.  Frogs naturally fertilize externally, facilitating the study of their fertilization in the lab.  Furthermore, X. laevis are particularly well-suited for the experiments proposed here due to the large size of their eggs (~1.2 mm diameter) and ease of exogenous protein expression.

Our lab is interested in elucidating the signaling events that occur within the first minutes of sperm entry into the egg.  We use various techniques including electrophysiology and fluorescence imaging to establish the timeline of events.

E-mail Lab

Wozniak, K.L., B.L. Mayfield, A.M. Duray, M. Te

Wozniak, K.L., B.L. Mayfield, A.M. Duray, M. Tembo, D.O. Beleny, M.A. Napolitano, M.L. Sauer, B.W. Wisner, and A.E. Carlson (2017) Extracellular Ca2+ Is Required for Fertilization in the African Clawed Frog, Xenopus laevis. PLoS One 12: e0170405.

Carlson, A.E., J.C. Rosenbaum, T.I Brelidze, R.

Carlson, A.E., J.C. Rosenbaum, T.I Brelidze, R.E. Klevit, and W.N. Zagotta (2013)  Fisetin potentiates HCN2 channels. Journal of Biological Chemistry 288: 33136-45.

Haitin, Y., A.E. Carlson, and W.N. Zagotta (201

Haitin, Y., A.E. Carlson, and W.N. Zagotta (2013) Structural mechanism for regulation of KCNH channels by the EAG domain. Nature 501: 444-8.

Carlson, A.E., T.I Brelidze, and W.N. Zagotta (

Carlson, A.E., T.I Brelidze, and W.N. Zagotta (2013) Flavonoid Regulation of EAG1 channels. Journal of General Physiology 141: 347-58.

Brelidze, T.I., A.E. Carlson, B. Sankarian, and

Brelidze, T.I., A.E. Carlson, B. Sankarian, and W.N. Zagotta (2012) Structure of the carboxy-terminal region of a KCNH Channel. Nature 481: 530-3.

Carlson, A.E., T.I. Brelidze (co-first author),

Carlson, A.E., T.I. Brelidze (co-first author), D.R. Davies, L J. Stewart, and W.N. Zagotta (2010) Identifying regulators for EAG1 channels with a novel electrophysiology and tryptophan fluorescence based screen.  PLoS One 5: e12523.

Carlson, A.E., L.A. Burnett, D. del Camino, T.A

Carlson, A.E., L.A. Burnett, D. del Camino, T.A. Quill, B. Hille, J.A. Chong, M.M. Moran, D.F. Babcock (2009) Pharmacological targeting of native CatSper channels reveals a required role in maintenance of sperm hyperactivation. PLoS One 4: 1-9.

Brelidze, T.I., A.E. Carlson, W.N. Zagotta (200

Brelidze, T.I., A.E. Carlson, W.N. Zagotta (2009) Absence of a direct cyclic nucleotide modulation of mEAG and hERG1 channels revealed with fluorescence and electrophysiological methods. Journal of Biological Chemistry 284: 27989-97.

Carlson, A.E., B. Hille, D.F. Babcock (2007) Ex

Carlson, A.E., B. Hille, D.F. Babcock (2007) External Ca2+ acts upstream of adenylyl cyclase SACY in the bicarbonate signaled activation of sperm motility.  Developmental Biology 312: 183-92.

Xie, F., M.A. Garcia, A.E. Carlson, S.M. Schuh,

Xie, F., M.A. Garcia, A.E. Carlson, S.M. Schuh, B.S. Jaiswal, M. van Duin, D.F. Babcock, and M. Conti.  2006.  Soluble adenylyl cyclase is indispensable for sperm function and fertilization.  Developmental Biology 296: 353-362.

Schuh, S.M., A.E. Carlson, G.S. McKnight, M. Co

Schuh, S.M., A.E. Carlson, G.S. McKnight, M. Conti, B. Hille, D.F. Babcock.  2006.  Signaling pathways for modulation of mouse sperm motility by adenosine and catecholamine agonists.  Biology of Reproduction 74: 492-500.

Carlson, A.E., T. Quill, R.E. Westenbroek, S.M.

Carlson, A.E., T. Quill, R.E. Westenbroek, S.M. Schuh, B. Hille, and D.F. Babcock (2005) Identical phenotypes of CatSper1 and CatSper2 null sperm Journal of Biological Chemistry. 280: 32238-44.

Carlson, A.E., R.E. Westenbroek, T. Quill, D. R

Carlson, A.E., R.E. Westenbroek, T. Quill, D. Ren, D.E. Clapham, B. Hille, D.L. Garbers, and D.F. Babcock (2003) CatSper1 required for evoked Ca2+ entry and control of flagellar function in sperm. Proceedings of the National Academy of Science 100: 14864-8.

Wennemuth, G., A.E. Carlson, A.J. Harper, and D

Wennemuth, G., A.E. Carlson, A.J. Harper, and D.F. Babcock (2003) Bicarbonate actions on flagellar and Ca2+ -channel responses: Initial events in sperm activation.  Development 130: 1317-26.

Rosenbaum, T., L.D. Islas, A.E. Carlson, and S.

Rosenbaum, T., L.D. Islas, A.E. Carlson, and S.E. Gordon (2003) Dequalinium: A novel, high-affinity blocker of CNGA1 channels. Journal of General Physiology 121: 37-47.
Dr. Carlson received her Ph.D. in 2006 with Bertil Hille and performed postdoctoral studies with William Zagotta at the University of Washington. She joined the department in 2014.