Skip to main content Accessibility help

Amino acid carryover in the subzonal space of mouse fertilized ova affects subsequent transport kinetics

  • Nirmala Rudraraju (a1) (a2) and Jay M. Baltz (a3) (a1) (a4) (a2)


We have investigated whether culture in glycine-containing medium affects subsequent glycine transport by the specific transport system, GLYT1, which is the sole glycine transporter in fertilized mouse ova. When fertilized ova were maintained for 6 h in culture with a physiological level of glycine (1 mM), subsequent transport of radiolabelled glycine was decreased by 40% compared with fertilized ova that had been maintained in glycine-free medium. Kinetic measurements showed that the apparent glycine affinity was decreased after culture with glycine (Km increased from 0.20 to 0.41 mM), but maximal transport rate was unchanged (similar Vmax of 20 and 23 fmol/fertilized ovum/min). These findings could have reflected activation of GLYT1 by prolonged substrate starvation, similar to some other amino acid transport systems. However, our findings were instead consistent with the alteration in glycine transport being due to trapping of glycine within the zona pellucida resulting in competitive transport inhibition even after ova were removed from glycine-containing media. First, even very brief exposures to glycine resulted in decreased subsequent glycine transport rates, with a maximal effect apparent within ~6 min. Second, extensive washing (at least six) reversed the effect. Third, the effect was absent when zona-free fertilized ova were used. Thus, it appears that components of the external environment of preimplantation embryos may continue to affect transport kinetics for a period even after embryos are removed from environments that contain them.


Corresponding author

All correspondence to: Jay M. Baltz. Moses and Rose Loeb Research Centre, Ottawa Health Research Institute, 725 Parkdale Ave., Ottawa, Ontario K1Y 4E9, Canada. Tel: +1 613 798 5555 ext. 13714. e-mail:


Hide All
Biggers, J.D., Whittingham, D.G. & Donahue, R.P. (1967). The pattern of energy metabolism in the mouse oocyte and zygote. Proc. Natl. Acad. Sci. USA 58, 560–7.
Carayannopoulos, M.O., Chi, M.M., Cui, Y., Pingsterhaus, J.M., McKnight, R.A., Mueckler, M., Devaskar, S.U. & Moley, K.H. (2000). GLUT8 is a glucose transporter responsible for insulin-stimulated glucose uptake in the blastocyst. Proc. Natl. Acad. Sci. USA 97, 7313–8.
Dandekar, P. & Talbot, P. (1992). Perivitelline space of mammalian oocytes: extracellular matrix of unfertilized oocytes and formation of a cortical granule envelope following fertilization. Mol. Reprod. Dev. 31, 135–43.
Dawson, K.M. & Baltz, J.M. (1997). Organic osmolytes and embryos: substrates of the Gly and beta transport systems protect mouse zygotes against the effects of raised osmolarity. Biol. Reprod. 56, 1550–8.
Dawson, K.M., Collins, J.L. & Baltz, J.M. (1998). Osmolarity-dependent glycine accumulation indicates a role for glycine as an organic osmolyte in early preimplantation mouse embryos. Biol. Reprod. 59, 225–32.
Franchi Gazzola, R., Sala, R., Bussolati, O., Visigalli, R., Dall'Asta, V., Ganapathy, V. & Gazzola, G.C. (2001). The adaptive regulation of amino acid transport system A is associated to changes in ATA2 expression. FEBS Letts. 490, 1114.
Gardner, D.K. & Lane, M. (1996). Alleviation of the ‘2-cell block’ and development to the blastocyst of CF1 mouse embryos: role of amino acids, EDTA and physical parameters. Hum. Reprod. 11, 2703–12.
Guerin, J.F., Gallois, E., Croteau, S., Revol, N., Maurin, F., Guillaud, J. & Menezo, Y. (1995). Techniques de récolte et aminogrammes des liquides tubaire et folliculaire chez les femelles domestiques. Revue Med. Vet. 146, 805–14.
Gwatkin, R.B. (1967). Passage of mengovirus through the zona pellucida of the mouse morula. J. Reprod. Fertil. 13, 577–8.
Harding, E.A., Day, M.L., Gibb, C.A., Johnson, M.H. & Cook, D.I. (1999). The activity of the H+-monocarboxylate cotransporter during pre-implantation development in the mouse. Pflugers Arch. 438, 397404.
Harris, S.E., Gopichandran, N., Picton, H.M., Leese, H.J. & Orsi, N.M. (2005). Nutrient concentrations in murine follicular fluid and the female reproductive tract. Theriogenology 64, 9921006.
Lawitts, J.A. & Biggers, J.D. (1993). Culture of preimplantation embryos. Methods Enzymol. 225, 153–64.
Leese, H.J. & Barton, A.M. (1984). Pyruvate and glucose uptake by mouse ova and preimplantation embryos. J. Reprod. Fertil. 72, 913.
Legge, M. (1995). Oocyte and zygote zona pellucida permeability to macromolecules. J. Exp. Zool. 271, 145–50.
Pastor-Anglada, M., Felipe, A., Casado, F.J., Ferrer-Martinez, A. & Gomez-Angelats, M. (1996). Long-term osmotic regulation of amino acid transport systems in mammalian cells. Amino Acids 11, 135–51.
Phillips, D.M. & Shalgi, R.M. (1980). Surface properties of the zona pellucida. J. Exp. Zool. 213, 18.
Steeves, C.L. & Baltz, J.M. (2005). Regulation of intracellular glycine as an organic osmolyte in early preimplantation mouse embryos. J. Cell. Physiol. 204, 273–9.
Steeves, C.L., Hammer, M.A., Walker, G.B., Rae, D., Stewart, N.A. & Baltz, J.M. (2003). The glycine neurotransmitter transporter GLYT1 is an organic osmolyte transporter regulating cell volume in cleavage-stage embryos. Proc. Natl. Acad. Sci. USA 100, 13982–7.
Tanaka, K., Yamamoto, A. & Fujita, T. (2005). Functional expression and adaptive regulation of Na+-dependent neutral amino acid transporter SNAT2/ATA2 in normal human astrocytes under amino acid starved condition. Neurosci. Letts. 378, 70–5.
Turner, K. & Horobin, R.W. (1997). Permeability of the mouse zona pellucida: a structure-staining-correlation model using coloured probes. J. Reprod. Fertil. 111, 259–65.
Van Winkle, L.J. (2001). Amino Acid Transport Regulation and Early Embryo Development. Biol. Reprod. 64, 112.
Van Winkle, L.J., Haghighat, N., Campione, A.L. & Gorman, J.M. (1988). Glycine transport in mouse eggs and preimplantation conceptuses. Biochim. Biophys. Acta 941, 241–56.


Related content

Powered by UNSILO

Amino acid carryover in the subzonal space of mouse fertilized ova affects subsequent transport kinetics

  • Nirmala Rudraraju (a1) (a2) and Jay M. Baltz (a3) (a1) (a4) (a2)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.